Representação da produtibilidade variável de usinas hidrelétricas no acoplamento entre os problemas do planejamento da operação energética de médio e curto prazos

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2020.O planejamento da operação energética de sistemas hidrotérmicos é resolvido com o apoio de vários modelos de otimização, que representam diferentes níveis de modelagem de acordo com os respectivos horizontes de estudo. No problema de médio prazo, cujo horizonte é plurianual, o sistema hidrelétrico é modelado com base no conceito de reservatório equivalente de energia. Por sua vez, no problema de curto prazo, o sistema hidrelétrico é representado por usinas individualizadas em um horizonte de poucos meses. O acoplamento entre os dois problemas de planejamento é feito pela inclusão da função de custo futuro (FCF), obtida no problema de médio prazo, no final do horizonte do problema de curto prazo. Dadas as características distintas de representação do sistema hidrelétrico, a FCF calculada no médio prazo deve ser desagregada para ser incluída no problema de curto prazo. Atualmente, a estratégia utilizada no acoplamento entre os problemas consiste em considerar constante a produtibilidade das usinas hidrelétricas para a conversão dos parâmetros do modelo equivalente em termos da modelagem individualizada. Neste contexto, este trabalho representa a produtibilidade em função do volume armazenado, permitindo assim uma melhor representação na desagregação do modelo equivalente. Contudo, a produtibilidade variável resulta em não linearidades, as quais precisam ser linearizadas no problema de curto prazo. Assim, são testadas duas estratégias, baseadas em envelopes de McCormick e restrições lineares inteiras mistas. Com um sistema teste de 7 usinas hidrelétricas e 7 termelétricas, são analisadas 7 árvores de cenários estocásticos de afluências, comparando as duas representações com a solução atual adotada pelo Setor Elétrico Brasileiro. Os resultados indicam diferenças significativas entre as produtibilidades resultantes das decisões fornecidas pelo acoplamento proposto e aquelas utilizadas pela atual solução do setor, indicando a necessidade de investigar um problema maior aplicado ao Sistema Interligado Nacional.Abstract: The generation scheduling problem of hydrothermal power systems is solved by several optimization models, which represent different modeling levels and planning horizons. The medium-term problem uses a composite representation of hydroelectric systems in a multiannual horizon. On the other hand, the short-term problem represents the hydroelectric systems through individual power plants in a few months? horizon. A future cost function (FCF) obtained from the medium-term problem allows coordinating both generation scheduling problems. Hence, the FCF calculated at the medium-term must be disaggregated to be included in the short-term problem due to the different hydroelectric system representations. The current strategy consists of using constant hydropower productivity coefficients to convert the composite representation parameters to individualized modeling. In this sense, this work considers hydropower productivity as a function of stored water volume, which allows a better representation for the equivalent model disaggregation. Nevertheless, the variable hydropower productivity results in nonlinearities, which must be linearized in the short-term problem. Thereby, two approaches are tested based on McCormick envelopes and mixed-integer linear constraints. Seven inflow scenario trees applied to a system of seven hydropower plants and seven thermal power plants allow analyzing the present solution adopted by the Brazilian Power Sector in contrast with both representations. Results attest significant differences between the hydropower coefficients calculated by the proposed coupling and those used by the Brazilian Power Sector, which indicates the necessity of a broader investigation based on the National Interconnected System

HPLC-DAD analysis and antifungal effect of Hyptis martiusii Benth (Lamiaceae) against Candida strains

Objective: To evaluate the anti Candida activity of Hyptis martiusii decoction and its major compound, caffeic acid alone or in the presence of fluconazole, as well as their cytotoxic effect. Methods: The decoction was characterized using high performance liquid chromatography coupled with diode array detector. For the antifungal activity, the minimum inhibitory concentration (MIC) and the potential effect of the decoction with the fluconazole were evaluated by microdilution method using 96-well microtiter trays. The osmotic fragility test was performed using erythrocytes under saline stress. All tests were performed in triplicate. Results: The chemical characterization of the decoction was performed by high performance liquid chromatography and revealed the presence of seven compounds, including caffeic acid as major constituent. The antifungal tests demonstrated that both decoction (DHm) and caffeic acid obtained from Hyptis martiusii presented MIC and MFC ≥ 4096 μg/mL against Candida albicans and Candida tropicalis strains. However, in the presence of fluconazole, DHm and caffeic acid presented IC50 of 2.60 and 2.53 μg/mL respectively, demonstrating significant synergistic effects against Candida strains. The modulator activity of DHm might be due to the presence of caffeic acid. Moreover, DHm and caffeic acid did not cause significant hemolytic effects, indicating that they present low cytotoxicity. Conclusions: These data indicate that DHm potentiates the activity of the fluconazole, without enhancement of the toxicity, encouraging further toxicological, pharmacological and phytochemical studies to provide consistent evidence of the potential of this plant to be used in drug development

Modulation of the Antibiotic Activity by the <i>Mauritia flexuosa</i> (Buriti) Fixed Oil against Methicillin-Resistant Staphylococcus Aureus (MRSA) and Other Multidrug-Resistant (MDR) Bacterial Strains

Mauritia flexuosa (buriti) is a typical Brazilian palm tree found in swampy regions with many plant forms. The fruit has various purposes with the pulps to the seeds being used for ice creams, sweets, creams, jellies, liqueurs, and vitamin production. A physicochemical characterization of the fixed pulp oil and its antibacterial and aminoglycoside antibiotic modifying activity against Gram-positive and Gram-negative multiresistant bacterial strains were performed using broth microdilution assays. Physical properties, such as moisture, pH, acidity, peroxide index, relative density, and refractive index, indicated oil stability and chemical quality. In the GC/MS chemical composition analysis, a high content of unsaturated fatty acids (89.81%) in relation to saturated fatty acids (10.19%) was observed. Oleic acid (89.81%) was the main fatty acid identified. In the antibacterial test, the fixed oil obtained the Minimum Inhibitory Concentration (MIC) &#8805; 1024 &#956;g/mL for all standard and multiresistant bacterial strains. The synergic effect of fixed pulp oil combined was observed only in Staphylococcus aureus SA&#8315;10, with an MIC reduction of the gentamicin and amikacin by 40.00% and 60.55%, respectively. The data indicates the M. flexuosa fixed oil as a valuable source of oleic acid and modulator of aminoglycoside activity

Antibacterial and antibiotic modifying activity, ADMET study and molecular docking of synthetic chalcone (E)-1-(2-hydroxyphenyl)-3-(2,4-dimethoxy-3-methylphenyl)prop-2-en-1-one in strains of Staphylococcus aureus carrying NorA and MepA efflux pumps

A large number of infections are caused by multi-resistant bacteria worldwide, adding up to a figure of around 700,000 deaths per year. Because of that many strategies are being developed in order to combat the resistance of microorganisms to drugs, in recent times, chalcones have been studied for this purpose. Chalcones are known as α, β-unsaturated ketones, characterized by having the presence of two aromatic rings that are joined by a three-carbon chain, they are a class of compounds considered an exceptional model due to chemical simplicity and a wide variety of biological activities, which include anticancer, anti-inflammatory, antioxidants, antimicrobials, anti-tuberculosis, anti-HIV, antimalarial, anti-allergic, antifungal, antibacterial, and antileishmanial. The objective of this work was evaluate the antibacterial and antibiotic modifying activity of chalcone (E)-1-(2-hydroxyphenyl)-3-(2,4-dimethoxy-3-methylphenyl)prop-2-en-1-one against the bacteria Staphylococcus aureus carrying a NorA and MepA efflux pump. The results showed that chalcone was able to synergistically modulate the action of Norfloxacin and Ethidium Bromide against the bacteria Staphylococcus aureus 1199B and K2068, respectively. The theoretical physicochemical and pharmacokinetic properties of chalcone showed that the chalcone did not present a severe risk of toxicity such as genetic mutation or cardiotoxicity, constituting a good pharmacological active ingredient

Essential Oil of Croton ceanothifolius Baill. Potentiates the Effect of Antibiotics against Multiresistant Bacteria

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2020-02-07T16:46:41Z No. of bitstreams: 1 Araújo, Essential....pdf: 480059 bytes, checksum: fae6482a0731dd97886ba0302a211c87 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2020-02-07T16:59:24Z (GMT) No. of bitstreams: 1 Araújo, Essential....pdf: 480059 bytes, checksum: fae6482a0731dd97886ba0302a211c87 (MD5)Made available in DSpace on 2020-02-07T16:59:24Z (GMT). No. of bitstreams: 1 Araújo, Essential....pdf: 480059 bytes, checksum: fae6482a0731dd97886ba0302a211c87 (MD5) Previous issue date: 2020-01-14Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Federal University of Paraná. Curitiba, PR, Brazil.Federal University of Paraná. Curitiba, PR, Brazil.Federal University of Paraná. Curitiba, PR, Brazil.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.Milan State University. Department of Agricultural and Environmental Sciences. Milan, Italy.Regional University of Cariri. Department of Biological Chemistry. Crato, CE, Brazil.This study is a pioneer in reporting the antibacterial properties of the species Croton ceanothifolius Baill. The genus Croton belongs to the family Euphorbiaceae composed of numerous species with documented biological activities. However, the pharmacological properties of C. ceanothifolius remain poorly understood. The leaves of this plant were submitted to hydrodistillation for essential oil (CcEO) extraction and the phytochemical characterization of the oil was performed by GC/MS. The minimum inhibitory concentration of the CcEO was determined for the evaluation of antibacterial activity against multiresistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The antibiotic-modulating activity of the oil, in combination with antibiotics, was also evaluated. The combination of the CcEO with penicillin, norfloxacin, and gentamicin presented a synergistic effect. This effect was more significant for the association with antibiotics of the quinolone and aminoglycoside classes against Escherichia coli. The association of oil with gentamicin showed better results with regard to the Gram-positive strain. The association of the oil with norfloxacin against P. aeruginosa also showed synergism, but the association with penicillin did not change the effect of this antibiotic. Thus, it is concluded that C. ceanothifolius essential oil selectively potentiates the action of antibiotics against multiresistant strains

Mechanisms of Actions Involved in The Antinociceptive Effect of Estragole and its &beta;-Cyclodextrin Inclusion Complex in Animal Models

(1) Background: estragole is a monoterpene found in the essential oils of several aromatic plants, which can be used for several pharmacological activities. The aim of this study was to evaluate the antinociceptive effect of estragole (Es) and its &beta;-cyclodextrins inclusion complex (Es/&beta;-CD). (2) Methods: the effects of Es and Es/&beta;-CD on the central nervous system (CNS) were evaluated through open field and rota-rod assays, and the antinociceptive effect in formalin models, abdominal writhing induced by acetic acid, hot plate, tail flick test and plantar mechanical hyperalgesia. (3) Results: Es and Es/&beta;-CD showed no alterations on the CNS evaluated parameters and the results suggested there was an antinociceptive action in the formalin, abdominal writhing, hot plate, tail flick tests and plantar mechanical hyperalgesia, proposing the involvement of the nitric oxide, glutamatergic signaling pathways, cyclic guanosine monophosphate and vanilloid pathways. (4) Conclusion: the results suggest that Es and Es/&beta;-CD have a promising antinociceptive potential as a possible alternative for the pharmacological treatment of pain, also showing that the encapsulation of Es in &beta;-cyclodextrins probably improves its pharmacological properties, since the complexation process involves much lower amounts of the compound, contributing to better bioavailability and a lower probability of adverse effect development

Antifungal Properties of Nerolidol-Containing Liposomes in Association with Fluconazole

(1) Background: Infections by Candida species represent a serious threat to the health of immunocompromised individuals. Evidence has indicated that nerolidol has significant antifungal properties. Nonetheless, its use is restricted due to a low water solubility and high photosensitivity. The incorporation into liposomes may represent an efficient alternative to improve the physicochemical and biopharmaceutical properties of this compound. The present study aimed to characterize the antifungal properties of liposomal nerolidol, alone or in combination with fluconazole. Of note, this is the first study reporting the antifungal activity of liposomal nerolidol and its potentiating effect in association with fluconazole. (2) Methods: The Inhibitory Concentration 50%-IC50 and minimum fungicide concentrations (MFC) of the substances against Candida albicans (CA), Candida tropicalis (CT), and Candida krusei (CK) were established by subculture in a solid medium. To evaluate the antifungal-enhancing effect, the MFC of fluconazole was determined in the presence or absence of subinhibitory concentrations of nerolidol (free or liposomal). The analysis of fungal dimorphism was performed through optical microscopy and the characterization of liposomes was carried out considering the vesicular size, polydispersion index, and zeta medium potential, in addition to a scanning electron microscopy analysis. (3) Results: The physicochemical characterization revealed that liposomes were obtained as homogenous populations of spherical vesicles. The data obtained in the present study indicate that nerolidol acts as an antifungal agent against Candida albicans and Candida tropicalis, in addition to potentiating (only in the liposomal form) the effect of fluconazole. However, the compound had little inhibitory effect on fungal dimorphism. (4) Conclusions: The incorporation of nerolidol into liposomes improved its antifungal-modulating properties