cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.19945209
title: EVALUATION OF CARBONIZED ARAUCARIACEAE WOOD FRAGMENTS WITH THERMOGRAVIMETRY AND FOURIER TRANSFORM INFRARED SPECTROSCOPY ASSOCIATED TO MULTIVARIATE ANALYSIS

description: The aim of the study is to evaluate the physical and chemical changes that occur on wood fragments submitted to different temperatures, verifying their influence on significant chemical characteristics in the forming process. Carbonization process in muffle associated to the techniques of Thermogravimetry, Fourier Transform Infrared Spectroscopy (FTIR) and multivariate analysis. The analyses were performed on 3 replicates for each burn temperature. The temperature of the thermal muffle process was in every 50 °C, from 200 °C to 600 °C. TGA were performed under nitrogen atmosphere, using a heating ramp from 25 °C min-1 to 995 °C. A range between 1900 to 650 cm-1 was used, with a resolution of 4 cm-1 and 64 scans. The PCA showed that it is possible to describe 95.73% of the data, grouping the samples into three main clusters. These clusters were used to build a SIMCA (Soft Independent Modeling of Class Analogy) model, enabling to predict with 100%. Results showed that technical associations, such as TGA, FTIR and multivariate analysis may help to characterize the natural carbonization process and, in future works, contribute to significant (paleo)environmental inferences.
DOI: 10.6084/m9.figshare.19945209.v1
title: EVALUATION OF CARBONIZED ARAUCARIACEAE WOOD FRAGMENTS WITH THERMOGRAVIMETRY AND FOURIER TRANSFORM INFRARED SPECTROSCOPY ASSOCIATED TO MULTIVARIATE ANALYSIS

description: The aim of the study is to evaluate the physical and chemical changes that occur on wood fragments submitted to different temperatures, verifying their influence on significant chemical characteristics in the forming process. Carbonization process in muffle associated to the techniques of Thermogravimetry, Fourier Transform Infrared Spectroscopy (FTIR) and multivariate analysis. The analyses were performed on 3 replicates for each burn temperature. The temperature of the thermal muffle process was in every 50 °C, from 200 °C to 600 °C. TGA were performed under nitrogen atmosphere, using a heating ramp from 25 °C min-1 to 995 °C. A range between 1900 to 650 cm-1 was used, with a resolution of 4 cm-1 and 64 scans. The PCA showed that it is possible to describe 95.73% of the data, grouping the samples into three main clusters. These clusters were used to build a SIMCA (Soft Independent Modeling of Class Analogy) model, enabling to predict with 100%. Results showed that technical associations, such as TGA, FTIR and multivariate analysis may help to characterize the natural carbonization process and, in future works, contribute to significant (paleo)environmental inferences.
DOI: 10.6084/m9.figshare.5734365
title: BEYOND CAIPIRINHA: BRAZILIAN CACHAÇA AS SOLVENT TO ORGANIC SYNTHESIS AND DYE EXTRACTION

description: Cachaça (brazilian sugarcane spirit) was applied for the first time as an alternative solvent in undergraduate experiments of organics synthesis, and natural dye extraction. The classical Claisen-Schmidt condensation of benzaldehyde with acetophenone and with acetone were employed to demonstrate the cachaça viability as solvent. Cachaça was also the recrystallization solvent of obtained benzalacetophenone and dibenzalacetone. The natural pigment of urucum (Bixa orellana L.) was obtained using as extractor solvent a 5% NaOH solution in cachaça. Considering that in Brazil cachaça is easily available and cheaper than the 40% mixture of ethanol/water, it can be found in every marketplace and is exported to 54 countries, the cachaça use as solvent is viable and attractive to green chemistry experiments in undergraduate courses, in Brazil and abroad.
DOI: 10.6084/m9.figshare.5734365.v1
title: BEYOND CAIPIRINHA: BRAZILIAN CACHAÇA AS SOLVENT TO ORGANIC SYNTHESIS AND DYE EXTRACTION

description: Cachaça (brazilian sugarcane spirit) was applied for the first time as an alternative solvent in undergraduate experiments of organics synthesis, and natural dye extraction. The classical Claisen-Schmidt condensation of benzaldehyde with acetophenone and with acetone were employed to demonstrate the cachaça viability as solvent. Cachaça was also the recrystallization solvent of obtained benzalacetophenone and dibenzalacetone. The natural pigment of urucum (Bixa orellana L.) was obtained using as extractor solvent a 5% NaOH solution in cachaça. Considering that in Brazil cachaça is easily available and cheaper than the 40% mixture of ethanol/water, it can be found in every marketplace and is exported to 54 countries, the cachaça use as solvent is viable and attractive to green chemistry experiments in undergraduate courses, in Brazil and abroad.
DOI: 10.6084/m9.figshare.5734260
title: SOLID STATE 13C NMR STUDY ON THE SYNTHESIS OF GRAPHITE OXIDE FROM DIFFERENT GRAPHITIC PRECURSORS

description: The influence of the structural and microstructural characteristics of graphitic precursors on the production of graphite oxide (GO) is investigated in the present work. Six different graphitic precursors were used to produce GO following a modified Hummers method, namely: natural graphite, commercial lubricant graphite, milled graphite, graphite flakes, high-purity graphite and graphite recycled from Li-ion batteries. The products were characterized by X-ray diffraction (XRD), thermogravimetry, solid-state 13C nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). 13C NMR spectra revealed the presence of epoxy, hydroxyl, carbonyl and lactol groups in the synthesized GOs. However, the oxidation degree of each product was found to be dependent on the average crystallite size (Lc) and particle size of the graphitic precursors, with the best GO samples being produced from the milled graphite and the graphite recycled from ion-Li batteries. These results were rationalized in terms of the structural and microstructural differences among the graphitic precursors, as revealed by the XRD patterns and SEM images, evidencing the importance of the correct choice of the precursor aiming the achievement of a well-developed structure for the GO product.
DOI: 10.6084/m9.figshare.5907436
title: ALCOHOLIC FERMENTATION OF HEMICELLULOSIC HYDROLYZATE FROM SUNFLOWER CAKE BY Galactomyces geotrichum UFVJM-R10 AND Candida akabanensis UFVJM-R131

description: The use of the hemicellulosic fraction of plants for the production of second generation bioethanol depends on microorganisms capable to ferment pentoses. Two yeast strains habile to xylose fermenting in synthetic medium, Candida akabanensis UFVJM-R131 and Galactomyces geotrichum UFVJM-R10, not yet registered in the literature for the production of bioethanol, were evaluated here in the alcoholic fermentation of the hemicellulosic hydrolyzate from sunflower cake. The biomass hydrolysis was performed by 38 minutes at 120 °C / 1 atm with 6% H2SO4 solution and solid / liquid ratio of 1:3.2. Chromatographic characterization of the hemicellulosic hydrolyzate showed the presence of glucose (7.57 g L-1), xylose (19.53 g L-1) and arabinose (8.85 g L-1), besides 5-hydroxymethylfurfural (0.71 g L-1), furfural (0.05 g L-1) and acetic acid (5.27 g L-1). Both yeasts were able to produce ethanol from the acid hydrolyzate from sunflower cake. The fermentation carried out with G. geotrichum UFVJM-R10 and C. akabanensis UFVJM-R131 presented YP/S values of 0.29 and 0.27 g ethanol g-1sugars, respectively. The amounts of the inhibitors identified in the hydrolyzate did not affect the efficiency of the alcoholic fermentation. The supplementation of the hydrolyzate with nitrogen and mineral sources increased the rate of consumption of xylose and arabinose.
DOI: 10.6084/m9.figshare.5907436.v1
title: ALCOHOLIC FERMENTATION OF HEMICELLULOSIC HYDROLYZATE FROM SUNFLOWER CAKE BY Galactomyces geotrichum UFVJM-R10 AND Candida akabanensis UFVJM-R131

description: The use of the hemicellulosic fraction of plants for the production of second generation bioethanol depends on microorganisms capable to ferment pentoses. Two yeast strains habile to xylose fermenting in synthetic medium, Candida akabanensis UFVJM-R131 and Galactomyces geotrichum UFVJM-R10, not yet registered in the literature for the production of bioethanol, were evaluated here in the alcoholic fermentation of the hemicellulosic hydrolyzate from sunflower cake. The biomass hydrolysis was performed by 38 minutes at 120 °C / 1 atm with 6% H2SO4 solution and solid / liquid ratio of 1:3.2. Chromatographic characterization of the hemicellulosic hydrolyzate showed the presence of glucose (7.57 g L-1), xylose (19.53 g L-1) and arabinose (8.85 g L-1), besides 5-hydroxymethylfurfural (0.71 g L-1), furfural (0.05 g L-1) and acetic acid (5.27 g L-1). Both yeasts were able to produce ethanol from the acid hydrolyzate from sunflower cake. The fermentation carried out with G. geotrichum UFVJM-R10 and C. akabanensis UFVJM-R131 presented YP/S values of 0.29 and 0.27 g ethanol g-1sugars, respectively. The amounts of the inhibitors identified in the hydrolyzate did not affect the efficiency of the alcoholic fermentation. The supplementation of the hydrolyzate with nitrogen and mineral sources increased the rate of consumption of xylose and arabinose.
DOI: 10.6084/m9.figshare.5907523
title: ELECTROCHEMICAL TREATMENT OF WASTEWATER FROM BIODIESEL PRODUCTION USING A DSA KIND ELECTRODE: Ti/IrO2-Nb2O5

description: This work presents the electrochemical treatment of wastewater of biodiesel production, using DSA based on IrO2 and Nb2O5. The anode was prepared by modified Pechini method and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), in order to evaluate structural and morphological properties and by electrochemical impedance spectroscopy, cyclic voltammetry and accelerated stability test to investigate the electrochemical behavior. The SEM image shows the typical mud-cracked layer. By the XRD measurements, the oxides onto the support were crystallized as tetragonal IrO2 and hexagonal Nb2O5. The amount of glycerin and methanol in the wastewater were 1.60 and 0.31% (w/w), respectively. The electrochemical treatment of the wastewater was evaluated by electrolysis at different current densities and time. The total organic carbon (TOC) and UV-Vis spectra were performed during the electrolysis. The UV-Vis spectra obtained during the electrolysis at 100 and 150 mA cm-2, shows the disappearance of an absorption band at 264 nm and the appearance of one at 290 nm, which the absorption increases as current and the time of the electrolysis increases. The electrochemical treatment with the proposed DSA leads to 80% of removal of TOC by electrolysis at 150 mA cm-2 during the first 6 hours of the electrochemical treatment.
DOI: 10.6084/m9.figshare.5907523.v1
title: ELECTROCHEMICAL TREATMENT OF WASTEWATER FROM BIODIESEL PRODUCTION USING A DSA KIND ELECTRODE: Ti/IrO2-Nb2O5

description: This work presents the electrochemical treatment of wastewater of biodiesel production, using DSA based on IrO2 and Nb2O5. The anode was prepared by modified Pechini method and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), in order to evaluate structural and morphological properties and by electrochemical impedance spectroscopy, cyclic voltammetry and accelerated stability test to investigate the electrochemical behavior. The SEM image shows the typical mud-cracked layer. By the XRD measurements, the oxides onto the support were crystallized as tetragonal IrO2 and hexagonal Nb2O5. The amount of glycerin and methanol in the wastewater were 1.60 and 0.31% (w/w), respectively. The electrochemical treatment of the wastewater was evaluated by electrolysis at different current densities and time. The total organic carbon (TOC) and UV-Vis spectra were performed during the electrolysis. The UV-Vis spectra obtained during the electrolysis at 100 and 150 mA cm-2, shows the disappearance of an absorption band at 264 nm and the appearance of one at 290 nm, which the absorption increases as current and the time of the electrolysis increases. The electrochemical treatment with the proposed DSA leads to 80% of removal of TOC by electrolysis at 150 mA cm-2 during the first 6 hours of the electrochemical treatment.
DOI: 10.6084/m9.figshare.19383749
title: Species-specific repeat libraries generated by RepeatModeler2 - Part 2

description: We identified repetitive elements (REs) in genome assemblies using RepeatModeler2.0 (Flynn et al. 2019) with search engine “ncbi”, which generated these libraries of repeat consensus sequences.<br><br><br><i>Authors: John S. Sproul, Scott Hotaling, Jacqueline Heckenhauer, Ashlyn Powell, Amanda M. Larracuente, Joanna L. Kelley, Steffen U. Pauls, and Paul B. Frandsen</i>
DOI: 10.6084/m9.figshare.5907850
title: DEVELOPMENT AND OPTIMIZATION OF A MICROWAVE-ASSISTED EXTRACTION OF PLUMIERIDE FROM Allamanda cathartica L. FLOWERS

description: A simple and efficient microwave-assisted extraction process has been developed in order to extract plumieride from Allamanda cathartica flowers. The extracts have been obtained through microwave-assisted extraction (MAE) process with ethanol and ethyl acetate at different time, power and temperatures. Static maceration at room temperature with ethanol and ethyl acetate was obtained in order to compare the efficiency of extraction. HPLC method was validated to quantify plumieride in the extracts. The analyzed parameters: linearity (R2 = 0.999), precision (CV 3.3%), recovery (98%), specificity (97%), limit of detection (1 µg mL-1), and limit of quantification (2 µg mL-1) were satisfactory. The yield of plumieride reached 43% in the extracts under the optimal MAE conditions (10 min, 300W). Plumieride recoveries by conventional extraction method were 12% with ethanol and 22% with ethyl acetate. Time and power parameters on plumieride extraction yield was determined by applying a factorial design and surface plots. Ethanol was the best extractor solvent and it was possible to obtain high contents (52 mg g-1 of dry flowers) at optimized conditions. It can be concluded that MAE process has actual advantages over the conventional extraction method in terms of shorter time and higher efficiency to recover plumieride from A. cathartica flowers.
DOI: 10.6084/m9.figshare.5907850.v1
title: DEVELOPMENT AND OPTIMIZATION OF A MICROWAVE-ASSISTED EXTRACTION OF PLUMIERIDE FROM Allamanda cathartica L. FLOWERS

description: A simple and efficient microwave-assisted extraction process has been developed in order to extract plumieride from Allamanda cathartica flowers. The extracts have been obtained through microwave-assisted extraction (MAE) process with ethanol and ethyl acetate at different time, power and temperatures. Static maceration at room temperature with ethanol and ethyl acetate was obtained in order to compare the efficiency of extraction. HPLC method was validated to quantify plumieride in the extracts. The analyzed parameters: linearity (R2 = 0.999), precision (CV 3.3%), recovery (98%), specificity (97%), limit of detection (1 µg mL-1), and limit of quantification (2 µg mL-1) were satisfactory. The yield of plumieride reached 43% in the extracts under the optimal MAE conditions (10 min, 300W). Plumieride recoveries by conventional extraction method were 12% with ethanol and 22% with ethyl acetate. Time and power parameters on plumieride extraction yield was determined by applying a factorial design and surface plots. Ethanol was the best extractor solvent and it was possible to obtain high contents (52 mg g-1 of dry flowers) at optimized conditions. It can be concluded that MAE process has actual advantages over the conventional extraction method in terms of shorter time and higher efficiency to recover plumieride from A. cathartica flowers.
DOI: 10.6084/m9.figshare.6208124
title: POLYANILINE IN THE ENVIRONMENTAL SCENARIO: AN APPROACH ON HETEROGENEOUS PHOTOCATALYSIS

description: Polyaniline is a conducting polymer that has recently been studied regarding its potential in the removal of contaminants by heterogeneous photocatalysis. Since it is a polymer with a high absorption capacity of photons in the visible region, it promotes the photosensitization of catalysts that are typically inactive in solar systems. The increasing number of publications applying photocatalysis and composite catalysts based on polyaniline highlights the importance of this subject. This review systematizes the most important and specific contributions of composite catalysts formed by polyaniline. The main mechanisms proposed for photosensitization, which show the synergism between the phases of the composite, are summarized. Moreover, the relevance of morphology and conductivity of the composite catalyst, operating parameters (eg. pH, and light source contaminant) are some of the aspects discussed, revealing how these differ from traditional catalysts. Future prospects for the continuation and improvement of this issue mainly involve a greater variety of contaminant removal tests and understanding of relations between the structure of the material and its photocatalytic property.
DOI: 10.6084/m9.figshare.6208124.v1
title: POLYANILINE IN THE ENVIRONMENTAL SCENARIO: AN APPROACH ON HETEROGENEOUS PHOTOCATALYSIS

description: Polyaniline is a conducting polymer that has recently been studied regarding its potential in the removal of contaminants by heterogeneous photocatalysis. Since it is a polymer with a high absorption capacity of photons in the visible region, it promotes the photosensitization of catalysts that are typically inactive in solar systems. The increasing number of publications applying photocatalysis and composite catalysts based on polyaniline highlights the importance of this subject. This review systematizes the most important and specific contributions of composite catalysts formed by polyaniline. The main mechanisms proposed for photosensitization, which show the synergism between the phases of the composite, are summarized. Moreover, the relevance of morphology and conductivity of the composite catalyst, operating parameters (eg. pH, and light source contaminant) are some of the aspects discussed, revealing how these differ from traditional catalysts. Future prospects for the continuation and improvement of this issue mainly involve a greater variety of contaminant removal tests and understanding of relations between the structure of the material and its photocatalytic property.
DOI: 10.6084/m9.figshare.6208040
title: PHOTOELECTROCATALYSIS ON SEMICONDUCTORS: FROM THE FUNDAMENTALS TO ITS CONFORMATION AT THE NANOSCALE LEVEL

description: The science of semiconductors, essential in electronics, is pivotal also for the most active research fields of environmental science and engineering today - the development of solar energy conversions and advanced oxidation processes, exemplified by the harvesting of sun daylight to produce electric energy, environmentally friendly fuels and to clean up water from harmful pollutants. The advancement of such fields relies on the fundamentals of the photocatalysis at semiconductors, summarized in this review in language familiar to chemists. The theory and experimental onrush emerged mainly during the first half of the 20th century but the rising interest in the science of nanostructured materials in recent decades, besides many insights about the potential of this scale-down of sizes, also forced a revision of the theoretical models. Essentially, the interfacial model of the space-charge layer cannot explain the behavior of nanoparticulate films, even at doped conditions comparable to monocrystalline materials. The present work encompasses the conformation of classical photocatalytic models to the nanoscale size, critically reviewing their features and role for modern electrochemical applications.
DOI: 10.6084/m9.figshare.6208040.v1
title: PHOTOELECTROCATALYSIS ON SEMICONDUCTORS: FROM THE FUNDAMENTALS TO ITS CONFORMATION AT THE NANOSCALE LEVEL

description: The science of semiconductors, essential in electronics, is pivotal also for the most active research fields of environmental science and engineering today - the development of solar energy conversions and advanced oxidation processes, exemplified by the harvesting of sun daylight to produce electric energy, environmentally friendly fuels and to clean up water from harmful pollutants. The advancement of such fields relies on the fundamentals of the photocatalysis at semiconductors, summarized in this review in language familiar to chemists. The theory and experimental onrush emerged mainly during the first half of the 20th century but the rising interest in the science of nanostructured materials in recent decades, besides many insights about the potential of this scale-down of sizes, also forced a revision of the theoretical models. Essentially, the interfacial model of the space-charge layer cannot explain the behavior of nanoparticulate films, even at doped conditions comparable to monocrystalline materials. The present work encompasses the conformation of classical photocatalytic models to the nanoscale size, critically reviewing their features and role for modern electrochemical applications.
DOI: 10.6084/m9.figshare.6502802
title: REACTIVE MOLECULAR DYNAMICS SIMULATION AND CHEMICAL KINETIC EVALUATION OF COMBUSTION OF TRIETHYLALUMINIUM (TEA)

description: The combustion process of triethylaluminum is investigated by means of reactive molecular dynamics simulations using the ReaxFF force field. The behavior of the system in five different temperatures ranging from 2000-4000 K was evaluated. As a pyrophoric material, TEA reacts also with water, generating gaseous hydrogen, whose content increases with the system temperature. Rapid water formation and O2 depletion were observed and, using Arrhenius equation, the preexponential factor and activation energy were found to be 9.67E+09 s-1 and 1.242 kJ mol-1, respectively. The results obtained are in accordance to the expected for pyrophoric materials and the simulation in question can help elucidating and analyzing the complex reaction mechanism of TEA combustion.
DOI: 10.6084/m9.figshare.6502802.v1
title: REACTIVE MOLECULAR DYNAMICS SIMULATION AND CHEMICAL KINETIC EVALUATION OF COMBUSTION OF TRIETHYLALUMINIUM (TEA)

description: The combustion process of triethylaluminum is investigated by means of reactive molecular dynamics simulations using the ReaxFF force field. The behavior of the system in five different temperatures ranging from 2000-4000 K was evaluated. As a pyrophoric material, TEA reacts also with water, generating gaseous hydrogen, whose content increases with the system temperature. Rapid water formation and O2 depletion were observed and, using Arrhenius equation, the preexponential factor and activation energy were found to be 9.67E+09 s-1 and 1.242 kJ mol-1, respectively. The results obtained are in accordance to the expected for pyrophoric materials and the simulation in question can help elucidating and analyzing the complex reaction mechanism of TEA combustion.
DOI: 10.6084/m9.figshare.6832793
title: AVOCADO, SPENT COFFEE GROUNDS, LICURI AND COCONUT MILK FOR OIL EXTRACTION, BIODIESEL PRODUCTION, AND SPECTRAL ANALYSIS

description: An undergraduate organic chemistry experiment for oil extraction and biodiesel production using alternative biomass was developed, whereby oils of avocado, coconut and spent coffee grounds were obtained and submitted to transesterification reaction with CH3OH under NaOH catalysis. Avocado and coffee oils were obtained by typical extraction and coconut oil was obtained through water evaporation of coconut milk in a domestic microwave oven. The commercial oil of licuri (Syagrus coronate), a Brazilian native biomass, was also converted to biodiesel. All four oils and four biodiesels were characterized by 1H-NMR and FTIR, and a comparative study of these spectra reveled that FTIR analyses alone provides enough information to discriminate between oil and biodiesel and confirm transesterification reaction. Besides, the unsaturation degree of all oils was determined by 1H-NMR. A mechanistic proposal concerning the role of NaOH catalysis is presented, excluding the sodium methoxide formation.