560 resultados para Eletrodos de grafite
Resumo:
The PSFC (Pr0.5Sr0.5Fe1-xCuxO3-δ) is a new mixed oxide perovskite and has been studied and evaluated the cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs), mainly due to its good compatibility with the electrolyte (CGO) and its high ionic conductivity and electronic in intermediate temperature. In this work, PSFC powders with two different compositions (Pr0,5Sr0,5Fe0,8Cu0,2O3- PSFC5582 and Pr0,5Sr0,5Fe0,6Cu0,4O3-PSFC5564) were synthesized by the citrate method using a new route. The powders obtained were characterized by thermal analysis (Differential Scanning Calorimetry and Thermogravimetry), and the material calcined at 800, 900 and 1000 °C for 5h were analyzed by X-ray diffractometry (XRD), with the Rietveld refinement of the diffraction data and dilatometry. PSFC5582 composite films were obtained by screen printing of powder calcined at 1000 °C. The films were deposited on substrate ceria doped with gadolinia (CGO) and then sintered at 1050 °C for 2h. The electrochemical performance of the electrodes was evaluated by impedance spectroscopy and the interface electrode/electrolyte was observed by scanning electron microscopy (SEM). The specific resistance area (ASR) was 0.44 Ω.cm² at 800 °C, slightly lower than those reported in the literature for cathodes containing cobalt. The thermal expansion coefficients of both the PSFC compositions were obtained and varied between 13 and 15 x 10-6 °C-1 , in a temperature range of 200 to 650 °C, demonstrating the good thermal compatibility of cathodes with Ce0,9Gd0,1O1,95 electrolytes (CET = 12 x 10-6 °C).
Resumo:
Textile industry has been a cause of environmental pollution, mainly due to the generation of large volumes of waste containing high organic loading and intense color. In this context, this study evaluated the electrochemical degradation of synthetic effluents from textile industry containing Methylene Blue (AM) dye, using Ti/IrO2-Ta2O5 and Ti/Pt anodes, by direct and indirect (active chlorine) electrooxidation. We evaluated the influence of applied current density (20, 40 and 60 mA/cm2 ), and the presence of different concentrations of electrolyte (NaCl and Na2SO4), as well as the neutral and alkaline pH media. The electrochemical treatment was conducted in a continuous flow reactor, in which the electrolysis time of the AM 100 ppm was 6 hours. The performance of electrochemical process was evaluated by UV-vis spectrophotometry, chemical oxygen demand (COD) and total organic carbon (TOC). The results showed that with increasing current density, it was possible to obtain 100 % of color removal at Ti/IrO2-Ta2O5 and Ti/Pt electrodes. Regarding the color removal efficiency, increasing the concentration of electrolyte promotes a higher percentage of removal using 0,02 M Na2SO4 and 0,017 M NaCl. Concerning to the aqueous medium, the best color removal results were obtained in alkaline medium using Ti/Pt. In terms of organic matter, 86 % was achieved in neutral pH medium for Ti/Pt; while a 30 % in an alkaline medium. To understand the electrochemical behavior due to the oxygen evolution reaction, polarization curves were registered, determining that the presence of NaCl in the solution favored the production of active chlorine species. The best results in energy consumption and cost were obtained by applying lower current density (20 mA/cm2 ) in 6 hours of electrolysis.
Resumo:
Aim : To evaluate and to standardize surface electromyography (sEMG) normalization procedures for respiratory muscles by comparing muscle activation during Maximal Voluntary Isometric Contraction (MVIC) and Maximal Respiratory Pressures (MIP, MEP and sniff test). Methods: Healthy subjects were evalua ted regarding demographics, spirometry and sEMG during the five maneuvers: sniff test, MIP , MEP and Maximal Voluntary Isometric C ontraction (MVIC) of RA, SCM and SC A . For electrode placement, skin was prepared with abrasion, followed by shaving in the foll owing regions for acquisition of el ectromyographic signals: (1) SC M: lower third of the distance between the mastoid process and t he sternoclavicular joint; (2) SC A : 5 cm to the right from the sternoclavicular joint and at this point, up to 2 cm; and (3 ) RA: the level of umbilicus, 4 cm to the right. In electromyographic variables analysis , the data normality was assessed by Shapiro - Wilk test. Comparisons among studied maneuvers were performed by Friedman Test and Dunn’s post - hoc for multiple comparisons a mong inspiratory maneuvers, and Mann Whitney test for expiratory maneuvers. Subgroups differences between genders were performed by Student's t test or Mann - Whitney test according to data normality. Results: 35 subjects participated in the study, b ut 5 we re excluded (BMI> 25 kg/ m²). Sample consisted of 30 subjects (1 5 women), mean age 27.3±7.43 years, BMI 22.2 ± 1.69 kg/m² and spirometric indices within normal limits. Specific MVIC for SCM, SCA and RA showed the highest RMS. When we grouped sample into gender we found no difference among RMS values for the studied SCM maneuvers, while for SCA, MVIC SCM / SCA was the one with the highest RMS and for RA, MVIC RA in men. Once considering women, MVIC SCM/SCA showed the highest RMS for SCM, SCA and MVIC RA showed t he highest value for RA. Conclusion: MVIC for SCM, SCA and RA muscles showed the highest RMS values. When comparing RMS between the studied groups, there was no significant difference between men and women.
Resumo:
This work was performing effluent degradation studies by electrochemical treatment. The electrochemical oxidation (EO) hydroquinone (H2Q) was carried out in acid medium, using PbO2 electrode by galvanostatic electrolysis, applying current densities of 10 and 30 mA/cm2 . The concentration of H2Q was monitored by differential pulse voltammetry (DPV). The experimental results showed that the galvanostatic electrolysis process performance significantly depends on the applied current density, achieving removal efficiencies of 100% and 80 % and 10 applying 30 mA/cm2 , respectively. Furthermore, the electroanalytical technique was effective in H2Q be used as a detection method. In order to test the efficiency of PbO2 electrode, the electrochemical treatment was conducted in an actual effluent, leachate from a landfill. The liquid waste leachate (600ml effluent) was treated in a batch electrochemical cell, with or without addition of NaCl by applying 7 mA/cm2 . The efficiency of EO was assessed against the removal of thermo-tolerant coliforms, total organic carbon (TOC), total phosphorus and metals (copper, cobalt, chromium, iron and nickel). These results showed that efficient removal of coliforms was obtained (100%), and was further decrease the concentration of heavy metals by the cathode processes. However, results were not satisfactory TOC, achieving low total removal of dissolved organic load. Because it is considered an effluent complex were developed other tests with this effluent to monitor a larger number of decontamination parameters (Turbidity, Total Solids, Color, Conductivity, Total Organic Carbon (TOC) and metals (barium, chromium, lithium, manganese and Zinc), comparing the efficiency of this type of electrochemical treatment (EO or electrocoagulation) using a flow cell. In this assay was compared to electro streaming. In the case of the OE, Ti/IrO2-TaO5 was used as the anode, however, the electrocoagulation process, aluminum electrodes were used; applying current densities of 10, 20 and 30 mA/cm2 in the presence and absence of NaCl as an electrolyte. The results showed that EO using Ti/IrO2–TaO5 was anode as efficient when Cl- was present in the effluent. In contrast, the electrocoagulation flow reduces the dissolved organic matter in the effluent, under certain experimental conditions.
Resumo:
Electrochemical technologies have been proposed as a promising alternative for the treatment of effluents and contaminated soils. Therefore, the objective of this work was to study the treatment of contaminated soils and wastewaters using electrochemical technologies. Thus, the study regarding the scale-up of the electrochemical system with continuous flow treatment of wastewater of the petrochemical industry was investigated using platinum electrodes supported on titanium (Ti / Pt), and boron-doped diamond (BDD). The results clearly showed that under the operating conditions studied and electrocatalytic materials employed, the better removal efficiency was achieved with BDD electrode reducing the chemical oxygen demand (COD) from 2746 mg L-1 to 200 mg L-1 in 5 h consuming 56.2 kWh m-3 . The decontamination of soils and effluents by petrochemical products was evaluated by studying the effects of electrokinetic remediation for removal of total petroleum hydrocarbons (HTP) from contaminated soil with diesel. The efficiency of this process was dependent on the electrolyte used Na2SO4 (96.46%), citric acid (81.36%) and NaOH (68.03%) for 15 days. Furthermore, the effluent after treatment of the soil was treated by electrochemical oxidation, achieving a good elimination of the organic polluting load dissolved. Depending on the physical behavior of wastewater contaminated with oil (emulsified state); atrazine emulsified effluents were investigated. The main characteristics of the effluent produced during the washing of contaminated soil were studied, being dependent on the surfactant dosage used; which determined its electrolytic treatment with BDD. The electrochemical oxidation of emulsified effluent of atrazine was efficient, but the key to the treatment is reducing the size of micelles.
Resumo:
The treatment of wastewater is essential to human health. One of the most important steps is the disinfection treatment which uses chlorine to eliminate bacteria as required by environmental agencies. However, the identification of potentially toxic byproducts generated by this method, such as trihalomethanes, has stimulated the development of new alternative disinfection technologies. Among them, heterogeneous photocatalysis, TiO2 photocatalysis and electrochemical disinfection are considered suitable alternatives to the chlorination method. Thus, the present dissertation analyzes the evolution of active chlorine species in a synthetic NaCl solution and it is tested to treat a synthetic solution of the dye Reactive Blue 19 using boron-doped diamond (BDD) and ruthenium oxide (Ti/Ru0.3Ti0.7O2) as anodes. The indirect electrochemical process was discussed in terms of mineralization of the total organic load and percentage of color removal in order to evaluate the applicability of electrochemical technology. Electrochemical experiments were carried out with different current densities (25, 50 and 75 mA.cm-2) during 120 minutes. On the other hand, other important parameter in this study was the influence of the proportion sp3/sp2 on BDD anode on the performance of the evolution of active chlorine species which was investigated by electrolytic techniques (linear polarization), with the intention of determining the related training oxidizing species and consumption energy to chemical or electrochemical reactions. From the results, it can be noted that the BDD electrode showed better efficiency throughout the electrochemical process.
Resumo:
The treatment of wastewater is essential to human health. One of the most important steps is the disinfection treatment which uses chlorine to eliminate bacteria as required by environmental agencies. However, the identification of potentially toxic byproducts generated by this method, such as trihalomethanes, has stimulated the development of new alternative disinfection technologies. Among them, heterogeneous photocatalysis, TiO2 photocatalysis and electrochemical disinfection are considered suitable alternatives to the chlorination method. Thus, the present dissertation analyzes the evolution of active chlorine species in a synthetic NaCl solution and it is tested to treat a synthetic solution of the dye Reactive Blue 19 using boron-doped diamond (BDD) and ruthenium oxide (Ti/Ru0.3Ti0.7O2) as anodes. The indirect electrochemical process was discussed in terms of mineralization of the total organic load and percentage of color removal in order to evaluate the applicability of electrochemical technology. Electrochemical experiments were carried out with different current densities (25, 50 and 75 mA.cm-2) during 120 minutes. On the other hand, other important parameter in this study was the influence of the proportion sp3/sp2 on BDD anode on the performance of the evolution of active chlorine species which was investigated by electrolytic techniques (linear polarization), with the intention of determining the related training oxidizing species and consumption energy to chemical or electrochemical reactions. From the results, it can be noted that the BDD electrode showed better efficiency throughout the electrochemical process.
Resumo:
This study aimed to evaluate the potential of oxidative electrochemical treatment coupled with adsorption process using expanded perlite as adsorbent in the removal of textile dyes, Red Remazol and Novacron Blue on synthetic effluent. Dyes and perlite were characterized by thermogravimetry techniques (TG), Differential Scanning Calorimetry (DSC), Spectroscopy infrared (IR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. Electrochemical treatments used as anodes, Ti/Pt and Pb/PbO2 under different conditions: 60 minutes, current density 20, 40 e 60 mAcm-2, pH 1, 4.5 e 8 and temperature variation 20, 40 e 60 ºC. In the case of adsorption tests, contact time of 30 minutes for the Remazol Red dye and 20 minutes for Novacron Blue were established, while pH 1, 4.5 e 8, 500 mg adsorbent and temperature variation 20, 40 e 60 ºC were used for both treatments. The results indicated that both treatments, electroxidation/adsorption and the adsorption/electroxidation, were effective for removing color from synthetic solutions. The consumption of electricity allowed to evaluate the applicability of the electrochemical process, providing very acceptable values, which allowed us to estimate the cost. Total organic carbon (TOC) and Gas Chromatography linked mass spectrometer (GC-MS) analyzes were performed, showing that the better combination for removing organic matter is by Pb/PbO2 and perlite. Meanwhile, GC-MS indicated that the by-products formed are benzoic acid, phthalic acid, thiocarbamic acid, benzene, chlorobenzene, phenol-2-ethyl and naphthalene when Remazol Red was degraded. Conversely, aniline, phthalic acid, 1, 6 - dimethylnaphthalene, naphthalene and ion hidroxobenzenosulfonat was detected when Novacron Blue was studied. Analyses obtained through atomic absorption spectrometry showed that there was release of lead in the electrochemical oxidation of analyzes that were performed with the anode Pb/PbO2, but these values are reduced by subjecting the effluent to adsorption analysis. According to these results, sequential techniques electroxidation/adsorption and adsorption/electroxidation are to treat solutions containing dyes.
Resumo:
This study aimed to evaluate the potential of oxidative electrochemical treatment coupled with adsorption process using expanded perlite as adsorbent in the removal of textile dyes, Red Remazol and Novacron Blue on synthetic effluent. Dyes and perlite were characterized by thermogravimetry techniques (TG), Differential Scanning Calorimetry (DSC), Spectroscopy infrared (IR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. Electrochemical treatments used as anodes, Ti/Pt and Pb/PbO2 under different conditions: 60 minutes, current density 20, 40 e 60 mAcm-2, pH 1, 4.5 e 8 and temperature variation 20, 40 e 60 ºC. In the case of adsorption tests, contact time of 30 minutes for the Remazol Red dye and 20 minutes for Novacron Blue were established, while pH 1, 4.5 e 8, 500 mg adsorbent and temperature variation 20, 40 e 60 ºC were used for both treatments. The results indicated that both treatments, electroxidation/adsorption and the adsorption/electroxidation, were effective for removing color from synthetic solutions. The consumption of electricity allowed to evaluate the applicability of the electrochemical process, providing very acceptable values, which allowed us to estimate the cost. Total organic carbon (TOC) and Gas Chromatography linked mass spectrometer (GC-MS) analyzes were performed, showing that the better combination for removing organic matter is by Pb/PbO2 and perlite. Meanwhile, GC-MS indicated that the by-products formed are benzoic acid, phthalic acid, thiocarbamic acid, benzene, chlorobenzene, phenol-2-ethyl and naphthalene when Remazol Red was degraded. Conversely, aniline, phthalic acid, 1, 6 - dimethylnaphthalene, naphthalene and ion hidroxobenzenosulfonat was detected when Novacron Blue was studied. Analyses obtained through atomic absorption spectrometry showed that there was release of lead in the electrochemical oxidation of analyzes that were performed with the anode Pb/PbO2, but these values are reduced by subjecting the effluent to adsorption analysis. According to these results, sequential techniques electroxidation/adsorption and adsorption/electroxidation are to treat solutions containing dyes.
Resumo:
This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.
Resumo:
This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.
Resumo:
O autismo é um transtorno do desenvolvimento que se manifesta nos primeiros anos de vida e apresenta semiologia heterogênea. Esta patologia afeta a maturação do encéfalo e produz alterações sensoriais, de linguagem e de interação social no início na infância. O modelo experimental de autismo utilizando ácido valproico (VPA) durante o período gestacional tem sido demonstrado ter alta validade de face e permitir estudos tanto das bases neuropatológicas quanto neuro-funcionais durante o desenvolvimento. A despeito do recente interesse por este modelo como instrumento de compreensão dos aspectos básicos da fisiopatologia do autismo, a maioria dos estudos experimentais têm se concentrado nos aspectos comportamentais, histológicos e celulares. Neste trabalho, foram propostas estratégias experimentais de avaliação comportamental associadas a eletrofisiologia \textit{in vivo}, uma técnica que nunca fora utilizada para avaliação desse modelo. Animais controles e experimentais, submetidos previamente a um procedimento cirúrgico para implante de eletrodos crônicos, participaram de experimentos de livre exploração, interação social e condicionamento ao medo.
Resumo:
A number of studies in the areas of Biomedical Engineering and Health Sciences have employed machine learning tools to develop methods capable of identifying patterns in different sets of data. Despite its extinction in many countries of the developed world, Hansen’s disease is still a disease that affects a huge part of the population in countries such as India and Brazil. In this context, this research proposes to develop a method that makes it possible to understand in the future how Hansen’s disease affects facial muscles. By using surface electromyography, a system was adapted so as to capture the signals from the largest possible number of facial muscles. We have first looked upon the literature to learn about the way researchers around the globe have been working with diseases that affect the peripheral neural system and how electromyography has acted to contribute to the understanding of these diseases. From these data, a protocol was proposed to collect facial surface electromyographic (sEMG) signals so that these signals presented a high signal to noise ratio. After collecting the signals, we looked for a method that would enable the visualization of this information in a way to make it possible to guarantee that the method used presented satisfactory results. After identifying the method's efficiency, we tried to understand which information could be extracted from the electromyographic signal representing the collected data. Once studies demonstrating which information could contribute to a better understanding of this pathology were not to be found in literature, parameters of amplitude, frequency and entropy were extracted from the signal and a feature selection was made in order to look for the features that better distinguish a healthy individual from a pathological one. After, we tried to identify the classifier that best discriminates distinct individuals from different groups, and also the set of parameters of this classifier that would bring the best outcome. It was identified that the protocol proposed in this study and the adaptation with disposable electrodes available in market proved their effectiveness and capability of being used in different studies whose intention is to collect data from facial electromyography. The feature selection algorithm also showed that not all of the features extracted from the signal are significant for data classification, with some more relevant than others. The classifier Support Vector Machine (SVM) proved itself efficient when the adequate Kernel function was used with the muscle from which information was to be extracted. Each investigated muscle presented different results when the classifier used linear, radial and polynomial kernel functions. Even though we have focused on Hansen’s disease, the method applied here can be used to study facial electromyography in other pathologies.
Resumo:
A number of studies in the areas of Biomedical Engineering and Health Sciences have employed machine learning tools to develop methods capable of identifying patterns in different sets of data. Despite its extinction in many countries of the developed world, Hansen’s disease is still a disease that affects a huge part of the population in countries such as India and Brazil. In this context, this research proposes to develop a method that makes it possible to understand in the future how Hansen’s disease affects facial muscles. By using surface electromyography, a system was adapted so as to capture the signals from the largest possible number of facial muscles. We have first looked upon the literature to learn about the way researchers around the globe have been working with diseases that affect the peripheral neural system and how electromyography has acted to contribute to the understanding of these diseases. From these data, a protocol was proposed to collect facial surface electromyographic (sEMG) signals so that these signals presented a high signal to noise ratio. After collecting the signals, we looked for a method that would enable the visualization of this information in a way to make it possible to guarantee that the method used presented satisfactory results. After identifying the method's efficiency, we tried to understand which information could be extracted from the electromyographic signal representing the collected data. Once studies demonstrating which information could contribute to a better understanding of this pathology were not to be found in literature, parameters of amplitude, frequency and entropy were extracted from the signal and a feature selection was made in order to look for the features that better distinguish a healthy individual from a pathological one. After, we tried to identify the classifier that best discriminates distinct individuals from different groups, and also the set of parameters of this classifier that would bring the best outcome. It was identified that the protocol proposed in this study and the adaptation with disposable electrodes available in market proved their effectiveness and capability of being used in different studies whose intention is to collect data from facial electromyography. The feature selection algorithm also showed that not all of the features extracted from the signal are significant for data classification, with some more relevant than others. The classifier Support Vector Machine (SVM) proved itself efficient when the adequate Kernel function was used with the muscle from which information was to be extracted. Each investigated muscle presented different results when the classifier used linear, radial and polynomial kernel functions. Even though we have focused on Hansen’s disease, the method applied here can be used to study facial electromyography in other pathologies.
Resumo:
A aguardente de cana é uma bebida de grande importância económica para Cabo Verde, mais concretamente para as ilhas de Santiago, Brava, Nicolau e S. Antão, que apresentam boas condições climáticas para a produção de cana. O consumo tem vindo a crescer em todas as classes sociais e tem a pretensão de conquistar o mercado internacional. Mas isso gera dificuldades para os produtores de aguardente, que muitas vezes enfrentam barreiras para entrar no mercado externo, principalmente devido à qualidade do produto e à falta de padronização desta bebida. Este trabalho teve como objectivo obter uma identidade e qualidade padrão da aguardente de cana em Cabo Verde, portanto, fizeram-se 5 destilados na ESTM os quais foram avaliados sensorialmente quanto à padronização do produto e também quanto à qualidade através de comparação com duas aguardentes feitas por produtores cabo-verdianos. Para isso, foram preparados 40 litros de calda, dividida em 5 lotes de 7,5 litros no alambique, obtendo-se 5 destilados com 450, 470, 565, 300 e 430ml. Determinou-se o grau alcoólico, acidez total, teor furfural e teor de cobre dos destilados realizados na escola e em Cabo Verde. Os valores obtidos do grau alcoólico, acidez total e furfural encontramse dentro dos limites estabelecidos pela lei brasileira, com exceção para o furfural que apresentou um resultado positivo nas amostras dos destilados feitos em Cabo Verde, correspondente a 28,57%. Os valores de acidez total variaram entre 9,38 a 136,87 mg/100 ml (álcool anidrido). O cobre foi determinado através da técnica de espectroscopia de absorção atómica com câmara grafite. As amostras analisadas apresentaram valores de cobre que variaram de 0,406 a 7,380 mgL-1. Das amostras analisadas 71,43% estavam dentro do limite e 28,57 % apresentaram teores de cobre acima do permitido pela legislação. Relativamente à padronização das 5 amostras feitas na escola, demonstrou-se que a estrutura de dados apenas se evidenciou validada para os atributos oleosidade e aroma (p = 0.000 e p = 0.037, respetivamente). Comparando as amostras feitas na escola com as duas de Cabo Verde, mostrou-se que à cor franca (P <0,000) e aceitável (P <0,013), limpidez (P <0,000) brilhante e transparente (P <0,001), as variáveis independentes não exercem influências na variável dependente segundo o modelo proposto.