Doutorado em Química

URI Permanente para esta coleção

http://repositorio.ufes.br/handle/10/17501

Nível: início
Ano de início: 2014
Conceito atual na CAPES: 5
Ato normativo: Homologação da 85ª Reunião do CTC-ES, Parecer CNE/CES nº 163/2005.
Processo nº 23001.000081/2005-56 do Ministério da Educação.
Publicado no DOU 28/07/2005, seção 1, página 11)
Periodicidade de seleção: Anual
Área(s) de concentração: Química
Url do curso: https://quimica.vitoria.ufes.br/pt-br/pos-graduacao/PPGQ/detalhes-do-curso?id=956/a>

Navegar

Agora exibindo 1 - 20 de 78

Alcaloides dos bulbos das espécies Griffinia gardneriana (Herb.) Ravenna e Habranthus itaobinus Ravenna (amaryllidaceae): perfil químico e propriedades citotóxicas e genotóxicas
(Universidade Federal do Espírito Santo, 2018-08-23) Cole, Eduardo Roberto; Borges, Warley de Souza; Lacerda Junior, Valdemar; Endringer, Denise Coutinho; Santos, Reginaldo Bezerra dos; Kuster, Ricardo Machado; Cunha Neto, Álvaro
The Amaryllidaceae family is widely distributed throughout the world, being considered one of the 20 most important families among which they present alkaloids in their composition, exhibiting antiviral, antimalarial, anticancer and anticholinesterase activities, among others. This work aims to perform a chemical study on alkaloids of Griffinia gardneriana and Habranthus itaobinus bulbs, belonging to this family, to evaluate its cytotoxic and genotoxic properties and the role of caspase-3 as a molecular mediator of apoptosis induced by these compounds. Fractions enriched in alkaloids obtained from G. gardneriana and H. itaobinus bulbs were initially subjected to gas chromatography coupled to mass spectrometry (GC-MS) and then fractionated by different chromatographic techniques, such as molecular exclusion chromatography, column chromatography and preparative thin layer chromatography. The isolation and identification of the alkaloids was done by means of high performance liquid chromatography and mono- and bidimensional nuclear magnetic resonance, in addition to circular dichroism. Studies were carried out to evaluate the cytotoxicity of the enriched fractions by the MTT method using the OVCAR-3, J774 and L929 cell lines. In addition, the in vitro cytotoxicity and genotoxicity of the alkaloids isolated (through the MTT assay and micronucleus test) using tumoral (HepG2, MCF- 7, A549) and normal (L929, CHO-1-15) cell lines. In parallel, a study was developed to evaluate the correlation of the results obtained in the cytotoxicity assays by MTT and cytometry by image analysis. Molecular docking studies were performed to evaluate the free binding energies between the alkaloids isolated with the caspase-3 protein, described in the literature as the probable site of action of these compounds, also being calculated the theoretical inhibition constant, Ki. The GC-MS result of the enriched fractions evidenced the presence of only one alkaloid in G. gardneriana and five in H. itaobinus. Seven alkaloids of Amaryllidaceae, belonging to different type skeletons, all of them already well characterized in the literature, are some common ones to the two species (trisphaeridine and pretazettine), whereas others present only in G. gardneriana (lycorine and sanguinine) or in H. itaobinus (tazettine, 11- hydroxyvitattine and 2-a-7-dimethoxyhomolycorine). All enriched fractions showed cytotoxic action in the tested methods, but for the alkaloids isolated 11-hydroxyvitattine and 2-a-7-dimethoxyhomocolycorine were not cytotoxic, whereas tazettine, trisphaeridine and sanguinine presented activity only against the fibroblastic lineage. Lycorine and pretazettine were 10 to 30 times more cytotoxic than the other alkaloids, being active also for the cancerous lines, exhibiting time-dependent and concentration action, besides being genotoxic and able to promote the apoptosis via caspase-3. This result corroborates the data obtained in the docking studies in which these two compounds were among those with the highest binding affinity values.
Análise Multivariada de Dados em Petroleômica por Técnicas de Alta Resolução: Espectrometria de Massas de Ressonância Ciclotrônica de Íons por Transformada de Fourier e Ressonância Magnética Nuclear
(Universidade Federal do Espírito Santo, 2024-02-24) Folli, Gabriely Silveira; Romão, Wanderson; https://orcid.org/0000-0002-2254-6683; http://lattes.cnpq.br/9121022613112821; Filgueiras, Paulo Roberto; https://orcid.org/0000-0003-2617-1601; http://lattes.cnpq.br/1907915547207861; https://orcid.org/0000-0003-0665-7540; http://lattes.cnpq.br/1256230443856795; Neto, Álvaro Cunha; https://orcid.org/0000-0002-1814-6214; http://lattes.cnpq.br/7448379486432052; Rosa, Thalles Ramon; https://orcid.org/0000-0001-9913-5885; http://lattes.cnpq.br/2629035369494897; Terra, Luciana Assis; https://orcid.org/0000-0003-2687-9669; http://lattes.cnpq.br/4918273242518895; Chinelatto Júnior, Luiz Silvino; https://orcid.org/0000-0002-0974-0465; http://lattes.cnpq.br/8008284454162318
Crude oil is a complex matrix, and the more in-depth study of its chemical structure (Petroleomics) has begun to be adopted by high-resolution techniques such as Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and high-field nuclear magnetic resonance (NMR) spectroscopy. However, high-resolution data presents challenges in spectral processing due to spectral variations. Consequently, the objective of this thesis was to develop multivariate data analysis applications (classification, regression, and design of experiments) to help overcome some of the limitations posed by high-resolution data. The first objective was to investigate the spectral profiles of analytical instruments (NMR, FT-ICR MS, nearinfrared – NIR, mid-infrared – MIR, and high-efficiency gas chromatography – HTGC). It was observed that high-resolution spectra predominantly exhibited a discrete profile (less correlated variables), while lower-resolution spectra showed a more continuous profile (more correlated variables), making them better suited for information clustering methodologies. The second objective involved estimating the intermediate precision of high-resolution mass spectrometers (FT-ICR MS and Orbitrap MS). It was noticed that both equipment presented oil with similar classes, but FT-ICR MS attributed a higher number of statistically assigned signals and had a lower detection limit compared to Orbitrap MS, due to its higher sensitivity. Furthermore, repeatability and intermediate precision of both spectrometers, although similar, demonstrated better values for FT-ICR MS in comparison to Orbitrap MS. The third objective focused on optimizing experimental parameters for ESI(±)FT-ICR MS in crude oil analysis. Plackett-Burman filtering planning was used to identify significant parameters, and the optimal analysis conditions were determined through a full factorial design. Global desirability determined by spectral quality metrics served as the response parameter for all experimental designs. The fourth objective aimed to develop a variable selection method that identifies variable correlations (Angular Search Algorithm with Variance Inflation Factor – ASA-VIF) and applies it to high-field 1H NMR, comparing it with MIR and NIR in linear (Partial Least Squares, PLS) and non-linear (Support Vector Regression, SVR) regression. An outlier identification methodology for non-linear models was also created. The results demonstrated that 1H NMR performed better using ASA-VIF-SVR. Furthermore, this selection drastically reduced the amount of information in MIR and NIR compared to 1H NMR, as these instruments contained a greater amount of correlated information (see the first application chapter). The final objective involved constructing a methodology for generating virtual samples (synthetic samples and artificial outliers) in complex data group classification models. This was essential as sample balance is crucial for more reliable metrics. The models showed good performance using virtual samples in both linear (PLS-DA) and non-linear (SVR) methodologies and with highresolution (Orbitrap MS) and low-resolution (MIR) spectra. In conclusion, all objectives resulted in improvements in the treatment of complex data using highresolution techniques.
Aplicação da cromatografia gasosa bidimensional abrangente na caracterização de classes de compostos do petróleo
(Universidade Federal do Espírito Santo, 2019-09-19) Silva, Samantha Ribeiro Campos da; Castro, Eustaquio Vinicius Ribeiro de; https://orcid.org/0000-0002-7888-8076; http://lattes.cnpq.br/1055263403980509; https://orcid.org/; http://lattes.cnpq.br/8592661743827044; Cunha Neto, Alvaro; https://orcid.org/0000-0002-1814-6214; http://lattes.cnpq.br/7448379486432052; Franca, Hildegardo Seibert; https://orcid.org/0000-0001-6129-8793; http://lattes.cnpq.br/1284874997224988; Lacerda Junior, Valdemar ; https://orcid.org/0000000282575443; http://lattes.cnpq.br/9819471276433138; Santos, Roberto Pereira
Crude oil is the term used for a wide variety of oils extracted from sedimentary rocks. Due to the variety and complexity of oil matrices an important oil assay is to quantify the content of saturated, aromatic, resin and asphaltene compounds (SARA). However, proper separation of saturated and aromatic components depends on the internal phase of the chromatographic column and on the method used for its quantification. Here works were described: aiming at the relative quantification of nonpolar components present in the saturated petroleum fraction and the use silica gel modified with boric acid to obtain aromatic fractions enriched with nitrogen aromatic compounds. The results showed that GCxGC-qMS technique was efficient in the relative quantification of n-paraffins from C11 to C35 and of branched paraffins in the saturated petroleum fraction. In addition, it allowed the determination of bicyclic, tricyclic, tetracyclic and pentacyclic compounds. In general, the classes of monocyclic and iso-paraffin compounds were the most abundant in the undegraded petroleum saturated fraction. Relative quantification of normal and branched paraffins allowed an understanding of the pour point values of light oils (API gravity greater than 30). The modification of the silica gel (column) with boric acid in the separation of the aromatic components of petroleum was selective to obtain fractions enriched with nitrogen aromatic compounds. However, the nitrogenous components identified in the aromatics fraction are characteristic of resins. Combining the FT-ICR MS (ESI (±) and APPI (±) sources using the Intensity vs DBE graphs) and GCxGC-qMS techniques allowed to ratify the good selectivity of the modified silica gel for the elution of aromatic nitrogen compounds. In the FT-ICR MS analyzes it was possible to visualize intense signals in all ionization sources for the nitrogen classes. The other visualized classes, such as hydrocarbons and oxygenated, were shown as low intensity peaks, corroborating the efficiency of separation of the modified column for nitrogen compounds. The concentration of nitrogenous compounds in crude oils is generally less than 2 wt%, however, they are detrimental to the refining processes and knowledge of the nitrogenous species present in crude oil is desirable. Thus, the methodology using the silica gel modified with boric acid column aimed to supply this important refining demand.
Aplicação de rejeitos de mineração na degradação de corante utilizado em laboratório de análises clínicas por processo Fenton
(Universidade Federal do Espírito Santo, 2022-10-07) Biazati, Luciana Brunhara; Castro, Eustaquio Vinicius Ribeiro de; https://orcid.org/; http://lattes.cnpq.br/1055263403980509; https://orcid.org/; http://lattes.cnpq.br/; Neto, Renato Rodrigues; https://orcid.org/; http://lattes.cnpq.br/1931267781220159; Sena, Denise Rocco de; https://orcid.org/; http://lattes.cnpq.br/; Lima, Edgar Alexandre Reis de; https://orcid.org/; http://lattes.cnpq.br/; Lelis, Maria de Fatima Fontes; Moura, Paulo Rogerio Garcez de; http://lattes.cnpq.br/9815585530252572
abstract
Aprendizagem de máquina na solução de problemas químicos: floresta aleatória aplicada à espectrometria na região do infravermelho
(Universidade Federal do Espírito Santo, 2023-02-13) Nascimento, Márcia Helena Cassago; Filgueiras, Paulo Roberto; https://orcid.org/0000000326171601; http://lattes.cnpq.br/1907915547207861; https://orcid.org/0000-0001-5252-586X; http://lattes.cnpq.br/2620289110303573; Lima, Maria Tereza Weitzel Dias Carneiro; https://orcid.org/0000-0002-8731-5093; http://lattes.cnpq.br/9989703911201351; Ferrão, Marco Flôres; https://orcid.org/0000-0002-3332-0540; http://lattes.cnpq.br/7552747227876113; Almeida, Mariana Ramos de; https://orcid.org/0000-0002-2612-068X; http://lattes.cnpq.br/6690913086860156; Romão, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; Oliveira, Marcone Augusto Leal de
Chemometrics began in the 1970s with the publication of a series of studies entitled "Computerized Learning Applied Machines to Chemical Problems" which express the motivation for the emergence of this field of study: the need for multivariate methods developed by chemists to solve chemical problems. Over 54 years, this area has expanded and presented solutions for increasingly complex data generated by modern Analytical Chemistry. Among the machine learning methods adapted to problems from the chemical point of view, this study contributes to a greater understanding, adaptation, and application of the random forest (RF) method. It is an ensemble-based method of learning multiple classifier systems. RF can be as a multivariate calibration model or pattern recognition, the latter being the focus of this thesis. In addition to the historical context, we describe adaptations proposed for the RF method to solve Chemistry problems with different analytical techniques and approaches. In this study, we applied RF for unsupervised pattern recognition as a screening method in a case study of suspected fuel fraud of diesel samples submitted to Fourier transform spectroscopy in the mid-infrared region (FT-MIR). The interpretation of the URF through a principal coordinate graph (PCoA) allowed the screening of samples with adulteration confirmed by the test of physical-chemical parameters. In addition, we adapted and applied the URF method to contribute to another field of study: biospectroscopy. A large part of the studies in this field is to develop alternative diagnosis methods or liquid biopsy. It is possible through biofluids, and spectroscopy associated with chemometric methods to extract information from biochemical changes caused by the disease or infectious agent. We adapted URF to identify a discriminant structure in spectroscopic data from two studies: a noninvasive diagnosis of COVID-19 from saliva samples analyzed by FT-MIR, and a proposal for pattern recognition and diagnosis of COVID-19 from nasopharyngeal swab and FT-MIR. In the first, an ensemble of classification models distinguished saliva samples from COVID19-infected people with an accuracy of 85%, a sensitivity of 93%, and a specificity of 74%. In another, URF was a comprehensive and innovative way: a starting point for selecting relevant variables and input data for classification models. With the URF as input data for classification models, we classified biofluid samples collected with two types of swabs with 87.6% accuracy, 93.6% sensitivity, 79.4% specificity, and 0.898 F-Score. Different approaches in this study contribute to disseminating the versatility and efficiency of the RF method, in addition to innovating its adaptation, taking advantage of the potential of this method for the different problems addressed.
Aproveitamento de resíduos de Chrysanthemum morifolium da Agroindústria Capixaba para produção de larvicidas naturais
(Universidade Federal do Espírito Santo, 2021-03-01) Lima, Tamires Aliprandi; Kuster, Ricardo Machado; https://orcid.org/0000000289615348; http://lattes.cnpq.br/4149814906786366; https://orcid.org/; http://lattes.cnpq.br/; Braga, Soraia Cristina Gonzaga Neves; https://orcid.org/; http://lattes.cnpq.br/; Filgueiras, Paulo Roberto; https://orcid.org/0000000326171601; http://lattes.cnpq.br/1907915547207861; Romao, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; Neto, Alvaro Cunha; http://lattes.cnpq.br/7448379486432052; Simas, Naomi Kato
Chrysanthemum morifolium is a perennial species of the Asteraceae family. In Brazil its cultivation has as its main purpose to provide for the ornamental industry. In the agroindustrial process of the species, many residues are generated that do not prese
Atividade experimental problematizada (AEP) e ensino de quimiometria: uso do aplicativo portátil REDGIM® no contexto educacional superior
(Universidade Federal do Espírito Santo, 2023-09-18) Siqueira, Bruno Magela de Melo; Moura, Paulo Rogerio Garcez de; https://orcid.org/0000-0002-6893-3873; http://lattes.cnpq.br/9815585530252572; https://orcid.org/0000-0003-2074-5686; http://lattes.cnpq.br/4318692166120742; Romao, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; Silva, André Luís Silva da; https://orcid.org/0000-0002-8245-9389; http://lattes.cnpq.br/0808253492421363; Mendes, Ana Nery Furlan; https://orcid.org/0000000164885483; http://lattes.cnpq.br/8266113579775016; Rosa, Thalles Ramon
This thesis addresses the theoretical-methodological strategy of Problematized Experimental Activity (PEA) in the teaching of Chemometrics, introducing innovative concepts in chemical analysis through digital images using the REDGIM® app in the context of Higher Education. Additionally, it explores the use of apps in predicting the concentration and pH of an ore dust suppressor resin as an alternative method with the use of portable technologies, in collaboration with the Doctoral Academic Innovation Scholarship - DAI (01/2019) and Vale Company. Despite the growing importance of Chemometrics in research and industry, its place in education is still limited. Universities have the responsibility to update future professionals, following the 2001 Curriculum Guidelines that emphasize a student-centered approach. Thus, PEA stands out as a theoretical-methodological strategy, combining experimentation and substantial learning, encouraging independent student research to solve complex problems and serving as a potential mediator for chemometric subjects. In terms of the methodology of this study, the approach is characterized as mixed, combining qualitative and quantitative procedures. Its applied nature aims to solve practical problems and offer tangible solutions. The research is descriptive, focusing on the interpretation of phenomena, and characterized as intervention research, as the researcher acts as a mediator, articulating the process and promoting interaction with the research subjects. The didactic and experimental planning developed was validated through applications over three years, both remotely and in-person, with undergraduate students in the Chemistry courses at the Federal University of Espírito Santo – Goiabeiras campus. Throughout these applications, data collection involved audio recordings, logbooks, photographic records, questionnaires, and assessment sheets based on cognitive performance indicators that analyze the competencies, skills, and intelligences developed and exercised by students. For the purpose of the technological innovation scholarship, apps were used to develop an alternative methodology for analyzing the ore dust suppressor resin. The results indicate that PEA demonstrated applicability in developing competencies and skills in students, such as collaboration, critical thinking, communication, creativity, and the ability to argue based on chemical knowledge. Content analysis of the final questionnaires, aided by the Iramuteq® software, highlighted how the use of an alternative app is interconnected with chemical knowledge and Chemistry education. Regarding the prediction of physicochemical properties of the resin, the proposed method yielded results close to those of established methods, demonstrating the potential use of apps in industrial analyses due to ease and low cost. In light of the foregoing, the combination of theoretical, experimental, and educational studies led to the conception of a plan for teaching Chemometrics and chemical analyses. This planning aimed to promote deep and meaningful learning, empowering students to deal with the complexities of the field and its applications in chemical analyses, preparing them solidly and updatedly for the challenges of the contemporary world.
Avaliação da distribuição de elementos químicos em sedimento marinho, água do mar e material particulado atmosférico da Região Metropolitana da Grande Vitória
(Universidade Federal do Espírito Santo, 2022-02-25) Dalfior, Bruna Miurim; Athayde, Geisamanda Pedrini Brandao; https://orcid.org/0000-0002-4315-0653; http://lattes.cnpq.br/8037324704189596; https://orcid.org/; http://lattes.cnpq.br/; Lima, Maria Tereza Weitzel Dias Carneiro; https://orcid.org/0000-0002-8731-5093; http://lattes.cnpq.br/9989703911201351; Neto, Renato Rodrigues; https://orcid.org/0000-0003-0803-4435; http://lattes.cnpq.br/1931267781220159; Borges, Daniel Lazaro Gallindo; https://orcid.org/0000-0001-7829-7180; http://lattes.cnpq.br/9529870514669368; Matos, Wladiana Oliveira; Sa, Fabian; https://orcid.org/0000000339645685; http://lattes.cnpq.br/9329106914297651
The urban and industrial growth around the Greater Vitória Metropolitan Region has awakened the need to monitor the area in order to investigate the impacts on the environment. For this work purpose, the concentration of chemical elements in a sample of marine sediment and in a sample of atmospheric material from the Region of Grande Vitória do Espírito Santo and a sample of atmospheric material from the Region of Grande Vitória and apparent is determined. Marine sediment and seawater samples were collected at 23 sampling points (5 quarterly campaigns). As a sample of atmospheric particulate matter (PM) from 16 sampling points, they were provided by the State Institute for the Environment (IEMA). A decrease in the concentration of elements in the 2C and 5C campaigns was observed for the sediment samples, which may have occurred due to climatic conditions with large volume of precipitation and high energy events. Among the elements determined in the sediment samples, the concentrations of As, Cd, Zn, V and Mn stand out, since they were higher than recommended in the quality guides by calculating contamination indices, which may be related to a natural contribution from the Barreiras Group, as well as anthropic sources, such as mining. For seawater samples, higher concentrations of Pb, Mn, Zn and, above all, Fe were observed, with some samples showing values higher than those recommended for water intended for primary contact recreation. Similar behavior to that of the sediments was observed for the water samples from the 2C and 5C campaigns, which presented the lowest concentrations. Through the treatment of the concentration data of the sediment and water samples (dissolved fraction) using Pearson's correlation, it was possible to observe low correlations, however, mostly negative, suggesting a small transfer of the elements between the matrices. In order to better evaluate the distribution of elements in the sedimentary matrix and in the fraction dissolved in the water, the partition coefficient was calculated for all sampling points. Log Kd values greater than O were observed for most elements, indicating greater association with the sedimentary matrix, highlighting Mn and Fe; however, Ni and Zn behaved in opposite ways, indicating them with greater availabilty and appreciable presence in the dissolved fraction of water. For the study of atmospheric particulate matter, in addition to the elements previously determined in the sediments, rare earth elements (REEs) in PM samples and some possible sources of increment for this material were determined. The results found indicate that for each of the analyzed sources it would be possible to use a group of REEs to be used as chemical markers. It was also observed that the particulate material samples showed greater similarities with the sand and iron ore samples with and without suppressor resin than with the cement and asphalt samples. As concentrations for most of the elements studied in the particulate material matrix are not foreseen in the environmental quality guides, it was not possible to infer about the air quality of the Greater Vitória Region. In view of the results presented, the importance of monitoring this region is verified, considering the activities that take place in the surroundings of these environmental areas.
Avaliação da taxa de corrosão do aço AISI 1020 em petróleo bruto e padrões de ácidos naftênicos
(Universidade Federal do Espírito Santo, 2019-06-07) Dias, Heloisa Pinto; Romao, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; https://orcid.org/; http://lattes.cnpq.br/5071058338667825; Nicolin, Viviane Azambuja Favre; https://orcid.org/0000-0001-6795-1167; http://lattes.cnpq.br/8203456381935461; Prado, Adilson Ribeiro; https://orcid.org/0000-0001-8808-4488; http://lattes.cnpq.br/3085491325255749; Filgueiras, Paulo Roberto; https://orcid.org/0000000326171601; http://lattes.cnpq.br/1907915547207861; Junior, Valdemar Lacerda; https://orcid.org/0000000282575443; http://lattes.cnpq.br/9819471276433138
It is common to use the total acid number (TAN) as a measure of the acidity of a Petroleum. However, naphthenic acids (NAs) vary in their structures and concentrations from one petroleum to another, even when the TAN value remains constant. Daily practice at the refineries has shown that oils with a NAT less than 0.5 mg of KOH·g-1 most often presents an unexpected corrosive behavior. Although naphthenic corrosion has been studied for years, its process is still not completely understood. Thus, the present study investigated the influence of solutions of molecules of linear, cyclic and aromatic NAs, (evaluating the effect of their concentrations, molar mass (Mw), and structural and electronic properties) in the corrosion rate under AISI 1020 steel, through tests at 320 ºC in 24H.The type and extent of corrosion were monitored by characterizing the surface of the specimens by light microscopy (LM), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The results showed that, even when the TAN was below the limit of detection, the value of the observed corrosion rate (CR) was significant, being considered high (TC < 0.19 mm·year-1) by the oil industry. At concentrations ≥ 5000 ppm of benzoic acids (BENA) and stearic (STA), the corrosion rate varied proportionally to the TAN. In addition, there was an inversely proportional correlation between the molar mass (Mw) and the number of aromatic rings of the NAs with their corrosive capacity. It was observed that the NAs standards containing a lower molar volume presented a higher corrosion rate. The images presented by SEM showed changes in the surface of all coupons exposed to NAs solutions, indicating that a protective layer was formed under the surface of the carbon steel coupon. The images by AFM revealed a topographic and phase profile deeply altered by the formation of valleys and peaks and variations in the mechanical properties of the AISI 1020 steel surface. The results obtained in this study are promising and confirm the influence of the electronic structural properties of organic acid molecules under naphthenic corrosion.
Avaliação dos Teores de Elementos em Amostras de Água e Sedimentos da Bacia Hidrográfica Rio Reis Magos - ES: Em Busca de Indícios de Impactos Antrópicos
(Universidade Federal do Espírito Santo, 2022-08-26) Barbieri, Eldis Maria Sartori; Athayde, Geisamanda Pedrini Brandao; https://orcid.org/0000-0002-4315-0653; http://lattes.cnpq.br/8037324704189596; https://orcid.org/; http://lattes.cnpq.br/; Souza, Jefferson Rodrigues de; https://orcid.org/0000-0002-3347-8735; http://lattes.cnpq.br/2386398242050923; Ribeiro, Juliano Souza; https://orcid.org/0000-0002-5685-7551; http://lattes.cnpq.br/6265921763953587; Ferreira, Rafael de Queiroz; https://orcid.org/; http://lattes.cnpq.br/5053247764430323; Lelis, Maria de Fatima Fontes
Anthropogenic activities can cause important environmental impacts, since the contribution of trace elements in ecosystems affect geochemical cycles and present toxicity to living beings. When these elements are carried to aquatic systems, they are distributed between water and sediments, and most of them accumulate in sediments due to adsorption, hydrolysis and co-capacity processes, therefore, they are potential sources of contamination, as they can re-available them in the water body. Therefore, research with sediments is fundamental to verify the anthropic contribution in the structure of these ecosystems, having as polluting sources direct discharges of effluents and solid residues, agricultural defensives, fertilizers, atmospheric deposition and sediment transport. With the water crisis, the Government of Espírito Santo (Brazil) started to use, in 2017, the Reis Magos River for public supply, however, this hydrographic basin has been suffering important environmental impacts, however, despite its importance, there is still no data provided published regarding its environmental quality. Thus, the present work aimed to quantify the requirements of As, Cd, Co, Cr, Cu, Fe, Mn, Hg, Ni, Pb, Sb e Zn, organic matter and carbonate content, pH, granulometric and crystallographic study in sediment. For water samples determination of pH, temperature (T), electrical conductivity, turbidity, oxydation reduction potential (ORP), dissolved oxygen (DO), total dissolved solids (TDS) and salinity of the Basin of the River Reis Magos. To assess the probability of adverse effects to biota, the values by the Canadian Council of Ministries of Environment that recommend threshold effect level (TEL) and probable effects level (PEL) concentration levels were adopted. In order to measure the degree of anthropogenic contribution, enrichment factors (EF), contamination (FC) and the geoaccumulation index (Igeo), pollution load index (PLI) and potential ecological risk (EF) were determined. The correlation between the variables made by principal component analysis (PCA), showing a direct relationship between the degree of source and proximity to the urban center, alkaline mineralogical characteristics cause an increase in pH and the higher the content of fines and organic matter, the greater the concentration of trace elements. For the water samples the concentrations of As, Cr, Cu and Fe presented more alarming values, above those allowed by law (10, 50, 9 and 300 µL L-1, respectively), mainly in the Reis Magos River. According to the general assessment, the sediments have mild to severe degrees of contamination, with a range of EF 5.67 - 384.02, suggesting a possible anthropic contribution.
Biofluidos e espectrometria de massas para triagem de pacientes para COVID-19
(Universidade Federal do Espírito Santo, 2024-02-28) Almeida, Camila Medeiros de; Mill, José Geraldo; https://orcid.org/0000-0002-0987-368X; http://lattes.cnpq.br/2497419234600362; Romão, Wanderson ; https://orcid.org/0000-0002-2254-6683; http://lattes.cnpq.br/9121022613112821; https://orcid.org/0000-0003-3318-8583; http://lattes.cnpq.br/4627760102080131; Chaves, Andrea Rodrigues ; https://orcid.org/0000-0002-1600-1660; http://lattes.cnpq.br/6064014965252121; Campos, Luciene Cristina Gastalho ; https://orcid.org/0000-0002-5962-661X; http://lattes.cnpq.br/6872591263471658; Cunha Neto, Alvaro ; https://orcid.org/0000-0002-1814-6214; http://lattes.cnpq.br/7448379486432052; Filgueiras, Paulo Roberto ; https://orcid.org/0000-0003-2617-1601; http://lattes.cnpq.br/1907915547207861
The COVID-19 disease has been and continues to be a global health concern. The identification of infected patients through rapid and efficient screenings remains necessary to contain its spread. Biological fluids, such as serum and saliva, offer ease of collection and provide rich information about molecular changes in the body during illness. The use of mass spectrometry (MS) combined with machine learning (ML) has been applied to biofluids from patients with diseases and controls to identify biomarkers and conduct rapid and effective screenings. Therefore, this thesis aims to present advancements in the search for disease biomarkers, particularly for COVID-19, using technologies based on Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS) and Electrospray Ionization Mass Spectrometry (ESI MS), along with chemometric data treatments. To achieve this, a methodology was developed for screening patients suspected of having COVID-19 based on saliva samples, using MALDI MS with the assistance of Support Vector Machine (SVM) learning. This involved optimizing sample preparation and analysis parameters. The most efficient results in a shorter analysis time were obtained by digesting saliva with 10 μL of trypsin for 2 hours. Optimization of the parameters at 1M resolution was ideal for the analyses. SVM models were created using data from the analysis of 149 samples, 97 positive and 52 negative for COVID-19. Two models yielded the best results. SVM1 selected 780 variables with a false negative rate (FNR) of 0%, while SVM2 selected only 2 variables (525.4 Da and 1410.8 Da) with a 3% FNR. Another application of MS in biofluids was the development of a multiomic method for screening patients infected with SARS-CoV-2 based on serum lipid and proteomic profiles. ESI MS was used to investigate the lipid profile of 239 serum samples (119 positive and 120 negative for COVID-19). MALDI MS was used to analyze the proteomic profile of 300 serum samples (150 positive and 150 negative for COVID-19). After processing MS data and variable selection, statistical analyses such as Volcano plot, Heatmap, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and SVM were performed to distinguish the most relevant variables for classifying positive and negative samples for COVID-19. In lipidomic analyses using ESI(±)-Orbitrap MS and SVM models, sensitivities of 96.67% and 100%, specificities of 82.14% and 96.88%, and accuracies of 89.66% and 98.44% were observed for positive and negative ion mode analyses, respectively. In proteomic analyses using MALDI(+) MS, the linear PLS-DA model demonstrated an accuracy of 99.10%. Thus, the combination of MS techniques with chemometric data treatments has shown promising alternatives with high sensitivity and specificity to discriminate infected and non-infected biological samples by SARS-CoV-2
Caracterização de asfaltenos e outros derivados do petróleo por ESI(±)FT-ICR MS
(Universidade Federal do Espírito Santo, 2019-06-18) Pinto, Fernanda Endringer; Romao, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; https://orcid.org/0000000223008481; http://lattes.cnpq.br/2271664099284682; Cardoso, Felipe Mauro Rena; https://orcid.org/0000-0002-2300-8481; http://lattes.cnpq.br/7445086243070619; Cunha Neto, Alvaro ; https://orcid.org/0000-0002-1814-6214; http://lattes.cnpq.br/7448379486432052; Junior, Valdemar Lacerda; https://orcid.org/0000000282575443; http://lattes.cnpq.br/9819471276433138; Souza, Lindamara Maria de
Positive and negative ion-mode electrospray (ESI(±)) technique coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) preferably provides ionization of polar constituents with ultra-high resolution and mass accuracy. The purpose of this research was to characterize asphaltenes and vacuum gasoil (VGO) by ESI(±)FT-ICR MS. Three asphaltenes subfractions obtained from precipitation with different n-hexane/crude oil ratios (3.5V, 3.5–6V, and 6–40V), and three subfractions obtained from adsorption onto CaCO3 (non-adsorbed, adsorbed, and irreversibly adsorbed), besides the original asphaltenes were analyzed. With the data generated from the ESI(±), solubility parameters (δ) were calculated. ESI(±) data showed that polar compounds species with lower carbon numbers were mainly found for the irreversibly adsorbed subfraction, while the subfraction 6-40V presented a more aromatic profile than of remaining subfractions. The δ obtained from the ESI(+) results showed an overlapping of Nx species indicating that subfractions produced in n-hexane had a lower tendency to precipitate in hydrocarbons in relation to subfractions produced onto CaCO3. The last presented a shift to higher δ for both ionization modes ESI(±), indicating that the fractionation onto CaCO3 was able to produce more distinct subfractions, with different δ, aromaticity, and polarity. The VGO samples consisted of VGO original and VGO treated with clay and silica obtain from breakthrough curves on two temperature levels (80 and 150 °C) and different rupture times (from 60 to 420 min). ESI(±) analyses of GOV and their fractions indicated that the removal of nitrogen compounds by the clay adsorbent was enhanced when the temperature was higher (150 °C). Conversely, silica has shown a rich adsorption capacity at moderate temperatures (80 °C). This result corroborates the existence of two different adsorption mechanisms. The clay adsorption mechanism is likely a chemisorption process, while the silica adsorption mechanism is related to physisorption. Both processes displayed better performance in short rupture times, for example, at 60 min. Class distribution showed a preferential removal of N[H] and N2[H] compounds with low carbon numbers (< C26) for ESI(+). However, the ESI(−) data showed that, although adsorbents, such as clay, present acid sites and selectively adsorb basic nitrogen species, a great reduction of non-basic nitrogen species, such as carbazole and its analogues, is clearly observed mainly for VGO samples treated with clay at 150 °C and with silica at 80 and 150 °C. The application of ESI (±) FT-ICR MS in the analysis of petroleum and derivatives facilitated the specific comparison of compounds between the samples, due to the ability of the equipment to monitor thousands of species present in the oil, with a high precision and mass resolution, as well a promise tool in the determination of different reaction mechanisms.
Caracterização dos Sistemas Praiais Adjacentes à Foz do Rio Doce (Espírito Santo, Brasil) quanto aos Teores de Elementos Químicos em Sedimentos e Material Particulado em Suspensão
(Universidade Federal do Espírito Santo, 2022-09-23) Krause, Maiara; Lima, Maria Tereza Weitzel Dias Carneiro; https://orcid.org/; http://lattes.cnpq.br/9989703911201351; https://orcid.org/; http://lattes.cnpq.br/; Souza, Jefferson Rodrigues de; https://orcid.org/; http://lattes.cnpq.br/; Athayde, Geisamanda Pedrini Brandao; https://orcid.org/; http://lattes.cnpq.br/8037324704189596; Ribeiro, Juliano Souza; https://orcid.org/; http://lattes.cnpq.br/; Sa, Fabian; https://orcid.org/0000000339645685; http://lattes.cnpq.br/9329106914297651
abstract
Compostos fenólicos em folhas de Eugenia uniflora L.: atividade citotóxica em adenocarcinoma gástrico (células AGS) e atividade anti-Helicobacter pylori
(Universidade Federal do Espírito Santo, 2023-11-17) Oliveira, Fernanda Mirella Garcia de; Kuster, Ricardo Machado; https://orcid.org/0000000289615348; http://lattes.cnpq.br/4149814906786366; https://orcid.org/0000-0002-0627-223X; http://lattes.cnpq.br/7757710237470773; Filgueiras, Paulo Roberto; https://orcid.org/0000000326171601; http://lattes.cnpq.br/1907915547207861; Gomes, Anne Caroline Candido; Franca, Hildegardo Seibert; http://lattes.cnpq.br/1284874997224988; Borges, Warley de Souza; https://orcid.org/0000000344751028; http://lattes.cnpq.br/9742402285970429
The infusion of Eugenia uniflora L. leaves is popularly used to treat viral and gastric symptoms, and the effectiveness of these treatments can be associated with the presence of flavonoids and tannins in its leaves. Eugenia uniflora L. is one of the species included in the National List of Medicinal Plants of Interest to the Unified Health System (RENISUS) and listed in the DRC on March 10, 2010 due to its importance in popular medicine. Furthermore, its leaves are used to treat sore throats, diarrhea, infections and gastrointestinal disorders. Among the secondary metabolites present in its composition, and which already have biological activities reported in the literature, flavonoids and tannins can be mentioned. Myricitrin is one of the flavonoids found abundantly in the leaves of Eugenia uniflora L. and has been associated with antioxidant, anti-inflammatory, antidiabetic, antihypertensive and antiviral activity. Oenotein B and gemin D/hipommannin A also have several related activities, including antibacterial activity. Thus, the objective of this study was to verify the anti-Helicobacter pylori activity and cytotoxicity of the extract and fractions of Eugenia uniflora L. leaves on gastric adenocarcinoma cells (AGS). Furthermore, verify better leaf collection conditions considering different locations (between mangrove, beach and mountain regions) and times (8:00 am, 1:00 pm and 6:00 pm), in addition to proposing FTIRPCA as a low-cost screening method for obtaining bioactive samples. The extracts and fractions had their chemical profiles determined by ESI(-)FT-ICR MS, ESI(-)FT-ICR MS/MS, ESI(-)LTQ MS and MSn. The aqueous fraction, rich in tannins, was considered the most active sample for Helicobacter pylori (MBC of 1024 µg/mL and MIC of 256 µg/mL) and the most cytotoxic for AGS cells (IC50 of 178 µg/mL). The strain analyzed showed resistance to metronidazole (MBC >1024 µg/mL and MIC of 512 µg/mL). For the FTIR-PCA analysis of the collection location, the samples from the beach and mangrove region were located in the PC1 > 0 direction, but separated along PC2. Those from the mountainous region were located at PC1 < 0. Regarding the separation by collection time, the samples collected at 1:00 pm were grouped at PC1 > 0. Considering the TIC values of the mass spectra and FTIR-PCA, the sample with the highest abundance of flavonoids is the one collected in the beach region at 1:00 p.m. In conclusion, the greatest cytotoxicity on AGS cells and anti Helicobacter pylori activity was found for the aqueous fraction of Eugenia uniflora L. leaves, which may be directly related to the presence of the tannins oenotein B and gemin D/hippomannin A. Finally, The best collection location and time to obtain bioactive extracts is at 1:00 pm in the beach area due to the high incidence of UV rays.
Desenvolvimento de Candidatos à Materiais de Referências com Aplicação em Química Forense
(Universidade Federal do Espírito Santo, 2022-03-31) Macrino, Clebson de Jesus; Romao, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; https://orcid.org/; http://lattes.cnpq.br/; Filgueiras, Paulo Roberto; https://orcid.org/0000000326171601; http://lattes.cnpq.br/1907915547207861; Chaves, Andrea Rodrigues; https://orcid.org/0000-0002-1600-1660; http://lattes.cnpq.br/6064014965252121; Costa, Jose Luiz da; https://orcid.org/0000-0001-9607-3391; http://lattes.cnpq.br/9846018023731358; Junior, Valdemar Lacerda; https://orcid.org/0000000282575443; http://lattes.cnpq.br/9819471276433138
The area of forensic chemistry has been growing and developing more and more as a research line in Brazil, and thus requires increasingly reliable results due to its importance in criminalistics. Thus, the development of new technologies that help this area, whether in the identity and quantification of drugs or in the fight against fraud, become promising. In this context, the present work explored the development of reference materials from the purification of drug samples seized by the Civil Police of the State of Espírito Santo (PCES), cocaine, crack and ecstasy tablets. The samples were isolated by croamtographic techniques. Benzoylecgonic was synthesized from cocaine alone. All substances were characterized by mass spectrometry and nuclear magnetic resonance. Homogeneity and stability studies were conducted with benzylecgonin, and the results were evaluated by variance analysis (ANOVA). Studies with europium III complexes have also been carried out for application in the fight against document and gasoline fraud. The complexes [Eu(pic)3(DVL)3], [Eu(pic)3(EPK)3] and [Eu(pic)3(OEN)3] were evaluated as new luminescent markers for application as security elements in Brazilian banknotes. And the complex [Eu(TTA)3(PRD)(H2O)] was studied to be applied as a luminescent sensor to combat adulteration of gasoline as ethanol.
Desenvolvimento de catalisadores de Pd modificados por Ag, Ru e Mo para atuar como ânodo em células a combustível de etanol direto em meio alcalino
(Universidade Federal do Espírito Santo, 2022-03-14) Filho, Yonis Fornazier; Ribeiro, Josimar; https://orcid.org/0000000295441647; http://lattes.cnpq.br/1265145498501171; https://orcid.org/0000-0002-5359-2316; http://lattes.cnpq.br/1227905675896069; Ribeiro, Marcos Antonio; https://orcid.org/0000000293506419; http://lattes.cnpq.br/3587612609487639; Colmati Junior, Flavio ; https://orcid.org/0000-0002-1867-0091; http://lattes.cnpq.br/0231242349462585; Luz, Priscilla Paiva; https://orcid.org/; http://lattes.cnpq.br/3663470249824660; Salgado, Jose Ricardo Cezar
Pd catalysts modified by Ag, Ru and Mo were produced by the thermal decomposition of polymeric percussor method to study their catalytic properties to ethanol oxidation reaction (EOR) in alkaline medium for fuel cells. Vulcan XC72 carbon was used as support, and the catalysts Pd/C, Pd60Ru40/C, Pd70Ru20Mo10/C, Pd60Ru20Mo20/C, Pd80Ag20/C, and Pd60Ag40/C were synthesized. Good experimental yields (Pd/C, Pd60Ru40/C, Pd70Ru20Mo10/C, Pd60Ru20Mo20/C, Pd80Ag20/C e Pd60Ru40/C = 97.1, 90.2, 97.9, 98.0, 98.6 e 96.5% respectively) and an increase in superficial area with addition of the metals were archieved (Pd/C, Pd60Ru40/C, Pd70Ru20Mo10/C, Pd60Ru20Mo20/C, Pd80Ag20/C e Pd60Ru40/C = 27.5, 100, 47.2, 38.9, 84.8 e 103.6 m2/g respectively). The X-ray diffraction and Raman spectroscopy results, showed formation of PdO for the Pd/C catalyst and RuO2 for the Pd60Ru40/C catalyst, a fact not observed for the other catalysts. Diffraction peak shifts were also observed for Pd70Ru20Mo10/C, Pd60Ru20Mo20/C, Pd80Ag20/C and Pd60Ag40/C, suggesting the formation of alloys in these catalysts. The electrochemical activities were investigated in alkaline medium, and an increase in the electrically active area was observed when the metals were combined with Pd and with the Ag-modified catalysts having the highest values (Pd/C, Pd60Ru40/C, Pd70Ru20Mo10/C, Pd60Ru20Mo20/C, Pd80Ag20/C e Pd60Ru40/C = 2.36, 4.63, 4.24, 3.04, 7.62 e 11.5 m2/g respectively). In the cyclic voltammetry tests for EOR in alkaline medium, the catalysts Pd70Ru20Mo10/C, and Pd60Ru20Mo20/C showed more negative onset potentials (-0.69 e -0.68 V respectively), suggesting that the initiation of the reaction was facilitated in these catalysts and the catalysts Pd80Ag20/C and Pd60Ag40/C had higher current densities at the oxidation peak (44.7 e 64.8 mA cm-2 respectively). In the chronoamperometry tests it was observed that the Pd60Ru40/C catalyst showed the lowest susceptibility to poisoning due to the bifunctional mechanism promoted by the presence of RuO2, followed by the PdAg/C catalysts, due to the electronic effect mechanism (intrinsic mechanism). From the CO-Stripping voltammetry results, in which the Pd60Ag40/C and Pd60Ru20Mo20/C catalysts showed a higher ability to remove CO intermediates from Pd active sites in EOR and stability tests, in which the catalyst Pd60Ag40/C had the highest values of current density after approximately 600 minutes of reaction (132 mA cm-2) and also because these catalysts have shown greater savings in the amount (Pd60Ag40/C ~ 36.65% e Pd60Ru20Mo20/C ~ 64.1 %) of Pd (a noble and expensive metal), it is concluded that these catalysts can be considered the most viable for commercial applications as anode in EOR in alkaline medium, being suggested more tests to investigate their properties.
Desenvolvimento de catalisadores heterogêneos suportados em carvões ativados e aplicações na síntese de biodiesel
(Universidade Federal do Espírito Santo, 2020-05-28) Faria, Diego Nunes; Freitas, Jair Carlos Checon de; https://orcid.org/0000000244742474; http://lattes.cnpq.br/3074997830683878; https://orcid.org/; http://lattes.cnpq.br/; Baranano, Audrei Gimenez; https://orcid.org/0000000201745202; http://lattes.cnpq.br/6155024776819193; Machado, Marta Albuquerque; https://orcid.org/; http://lattes.cnpq.br/5991893415892784; Neto, Alvaro Cunha; https://orcid.org/; http://lattes.cnpq.br/7448379486432052; Perez, Victor Haber
The development of heterogeneous catalysts useful in the reaction of biodiesel synthesis constitutes a subject of high interest from the environmental and technological points of view. This work describes the preparation and characterization of a series o
Desenvolvimento de novos métodos analíticos em química forense e petroleômica por espectrometria de massas ambiente (Paper Spray) e espectroscopia portátil na região do infravermelho próximo (MICRONIR)
(Universidade Federal do Espírito Santo, 2017-11-30) Domingos, Eloilson; Romão, Wanderson; Ferreira, Ernesto Correa; Ribeiro, Juliano Souza; Filgueiras , Paulo Roberto; Kuster, Ricardo Machado
With the advent of a new family of ionization techniques, ambient mass spectrometry (or ambient MS) was introduced as a simple way of generating ions in MS. Among them, the paper spray ionization (PS-MS) technique has demonstrated to be versatile to solve numerous problems in many areas of science. In this work, the PS-MS technique in the positive ionizationmode (PS(+)-MS) was applied in three subareas of forensic chemistry: drugs of abuse, documentoscopy, and herbal medicines. In the first, the PS(+)MS technique was applied to obtain the chemical profiles of illicit drugs such as drug stamps containing 25I-NBOMe, extracts and leaves of natural cannabinoids (?9-tetrahydrocannabinol) and synthetic cannabinoids (JWH-073; 5F-AKB48; JWH-122; JWH-250; e JWH-210). In all cases, molecules were easily detected in their protonated form ([M + H]+) with resolution of m/?m50%=67,000 and a mass precision <2 ppm. The performance of the PS(+)-MS technique was compared with other sources of ionization: leaf spray (LS-MS) and electrospray (ESI-MS). In addition, a method was developed to quantify a series of illicit drugs (from 1 to 110 ??g L-1, with linearity of R2> 0.99). In documentoscopy, the PS(+)-MS technique was able to successfully obtain the chemical profile of different pens commercially sold in stores. The relative intensity (RII372) of the methylene blue dye was monitored to discriminate crossing pen traces and, to date, questioned documents. The chemical profile of second-generation Brazilian notes of R$ 100.00 (reais) was also explored. The PS(+)-MS technique was able to classify notes into either authentic or counterfeit. Finding that fake samples have a chemical profile similar to the homemade notes of the Deskjet® printer. Finally, PS-MS was applied to verify the authenticity of herbs used for weight loss. Fifteen different herbal medicines were analyzed by PS(+)-MS, substances such as: sibutramine (m/z280), caffeine (m/z195), and glucose (m/z203 [M + Na], m/z219 [M + K] and sucrose (m/z381 [M + K]) were found in samples where they were not listed in the herbal medicine label. In general, the PS(+)-MS technique proved to be an excellent analytical tool in chemistry forensic. A second study developed wasquality control of fuel with the application of the portable micro-spectrometer inthe near infrared region (MICRONIR), which has proven to be an excellent analytical technique in the quality control of several products. In this work, the potential of the MICRONIR in the control of fuel quality was verified. Thus, chemometric models (PLS-Partial Least Squares regression) were developed using near-infrared data acquired in the MICRONIR to determine the amount of biodiesel in Diesel (LOD=0.5wt%; LOQ=1.8 wt%, RMSEP=1.8 wt%); sulfur in Diesel (LOD=2.4 mg L-1; LOQ=8.0 mg L-1, RMSEP=13.2 mg L-1); gasoline, ethanol and methanol in gasoline type C (LODgas=0.55 wt%; LOQgas=1.84 wt%, RMSEPgas=0.81 wt%; LOQgas=2.50 wt%, RMSEPeth=3.81 wt%, LODmet= 0.85 wt% LOQmeth= 2.84 wt%, RMSEPmeth=1.80 wt% ; and water, methanol and ethanol in ethanol hydrated fuel (LODH2O=0.04 wt%; LQH2O=1.29 wt%, RMSEPH2O=1.05 wt%; , LOQmeth=1.73 wt%, RMSEPmeth=2.78 wt%). The proposed method presented high precision and accuracy in all cases, and the results showed that the MICRONIR technique had excellent performance in the control of fuel quality.
Desenvolvimento de softwares para aplicações quimiométricas
(Universidade Federal do Espírito Santo, 2020-04-24) Rosa, Thalles Ramon; Filgueiras, Paulo Roberto; https://orcid.org/0000000326171601; http://lattes.cnpq.br/1907915547207861; https://orcid.org/; http://lattes.cnpq.br/; Vaz, Boniek Gontijo; https://orcid.org/; http://lattes.cnpq.br/; Romao, Wanderson; https://orcid.org/0000000222546683; http://lattes.cnpq.br/9121022613112821; Neto, Alvaro Cunha; https://orcid.org/; http://lattes.cnpq.br/7448379486432052; Moura, Paulo Rogerio Garcez de; http://lattes.cnpq.br/9815585530252572; Rocha, Ygor dos Santos
The present work developed two software based on multivariate analysis in two lines of research, petroleomics and digital image processing with a focus on colorimetry. In both areas, multivariate analysis boosts the interpretive capacity of the data, whic
DESENVOLVIMENTO DE UM MÉTODO ALTERNATIVO DE DESSALGAÇÃO E DESIDRATAÇÃO DE PETRÓLEOS PESADOS E EXTRAPESADOS
(Universidade Federal do Espírito Santo, 2019-02-15) Sad, Cristina Maria dos Santos; Castro, Eustaquio Vinicius Ribeiro de; https://orcid.org/; http://lattes.cnpq.br/1055263403980509; https://orcid.org/; http://lattes.cnpq.br/; Prado, Adilson Ribeiro; https://orcid.org/; http://lattes.cnpq.br/; Neto, Alvaro Cunha; https://orcid.org/; http://lattes.cnpq.br/7448379486432052; Santana, Hosiberto Batista de; https://orcid.org/; http://lattes.cnpq.br/; Junior, Valdemar Lacerda; https://orcid.org/0000000282575443; http://lattes.cnpq.br/9819471276433138
abstract

Navegar

Navegando Doutorado em Química por Título

Resultados por página

Opções de Ordenação