59 resultados para Algodão - Semente


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work aims to study the effects of adding antioxidants, such as, α- tocopherol and BHT on the thermal and oxidative stability of biodiesel from cottonseed (B100). The Biodiesel was obtained through the methylical and ethylical routes. The main physical and chemical properties of cotton seed oil and the B100 were determined and characterized by FTIR and GC. The study of the efficiency of antioxidants, mentioned above, in concentrations of 200, 500, 1000, 1500, 2000ppm, to thermal and oxidative stability, was achieved by Thermogravimetry (TG), Differential Thermal Analysis (DTA), Differential Scanning Calorimetry (DSC), Differential Scanning Calorimetry - Hi-Pressure (P-DSC) and Rancimat. The Biodiesel obtained are within the specifications laid down by Resolution of ANP No7/2008. The results of TG curves show that the addition of both antioxidants, even in the lowest concentration, increases the thermal stability of Biodieseis. Through the DTA and DSC it was possible to study the physical and chemical transitions occurred in the process of volatilization and decomposition of the material under study. The initial time (OT) and temperature (Tp) of oxidation were determined through the P-DSC curve and they showed that the α-tocopherol has a pro-oxidant behavior for some high concentrations. The BHT showed better results than the α-tocopherol, with regard to the resistance to oxidation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La historia de la expansión colonial en los sertónes del Seridó del siglo XVIII y el asentamiento de los primeros pobladores alrededor de las haciendas de ganado y más tarde de la cultura de algodón, oculto la presencia afrodescendiente que ya regia esa vasta región. Por otro lado, la esclavitud se observaba como un fenómeno de segunda prioridad y leve, por el hecho de tener un número de esclavos muy reducido en relación al litoral azucarero; sin embargo no se puede minimizar las marcas que dejaron más de tres siglos de dominación colonial, pues la violencia simbólica en su descripción aun existe. Este trabajo tiene como objetivo reflexionar sobre las causas y consecuencias de la extinción precoz de la presencia afro-brasileña y de la invisibilidad de los núcleos familiares en el municipio de Acari. A través de las memorias de las familias Nunes, Inácio y Pereira, antiguos moradores del Saco de los Pereira y de las familias Pedros, Paula, Higinos y Félix outroras moradores de las haciendas de la región, pretendemos reflexionar sobre las actividades de sobrevivencia, las relaciones de trabajo, la propiedad de la tierra y los robos ocurridos en los siglos XIX – XX, así como mostrar la importancia de las tradiciones familiares en la elaboración de los discursos sobre el pasado y de las variadas identidades. La metodología utilizada durante la investigación, mantuvo como foco las entrevistas que contemplan historias de la vida y las memorias de nuestros interlocutores, en particular los afrodescendientes. Los relatos colocan una luz sobre las vivencias en el período algodonero, los oficios realizados en las haciendas (vaquero, bordado, culinaria, losa) donde se muestra la importancia de las familias negras para entender el escenario Acarienses. También fotos y documentos cartoriáles que ayudaron a componer las historias de vida. El estudio revela la presencia de muchas familias negras vinculadas a las haciendas, demostrando que existe otra versión de la historia local, teniendo como protagonistas aquellos cuya memoria fue silenciada y quedando así marcados por el estigma de la esclavitud.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The present research deals with the modernization process of the Cidade da Parahyba2, between 1850 and 1924, and its relation with the cotton economy, which represented the main source of wealth accumulation for both the private and the public sectors throughout the First Republic. This study on urban history was developed by focusing on the understanding of the city s spatial formation, and despite its emphasis on the economic aspects involved, other factors that also contribute to the development of the social life were not put aside. The modernization process of the Cidade da Parahyba was also analyzed during the period established for the study according to a chronological and thematic approach that established comparisons with the financial situation of the State, whenever this was necessary, with special attention to the contribution of the cotton economy to the State´s revenues. It was possible to detect a lack of financial help and loans from the federal and municipal administrations for finishing several public works already underway in the capital, since the federal funds allocated to the State of Parahyba do Norte were rather employed in emergency works against droughts and in agricultural development. One can then conclude that the financial resources required for the urban interventions were withdrawn from the State s treasury itself, resources that were collected mainly from activities such as cotton exportation and cotton trading. Another factor shows the interdependence between the urban remodeling and the cotton economy: during the years marked by great droughts or by hard plagues on the cotton plantations, cotton production decreased, as well as the State s finances. The first measures taken by the State s administrators were to halt all projects of urban remodeling in progress in the Cidade da Parahyba, which was, clearly, the most privileged city by the State s presidents during the period analyzed. 2 The city of João Pessoa was named Cidade da Parahyba, a designation that remained until September 1930, when it received its present-day name in order to pay homage to the president of the State, João Pessoa Cavalcanti de Albuquerque, murdered in the city of Recife in August of that same year. At that time, the State of Paraíba was known as Parahyba do Norte. Since this work is limited to a period of time comprised within the First Republic, the names employed respect the terms used in those days

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A chymotrypsin inhibitor was purified from Erythrina velutina seeds by ammonium sulphate fractionation, affinities chromatographies on Trypsin-Sepharose, Quimotrypsin-Sepharose and reversed phase C-18 FPLC/AKTA system. The inhibitor, named EvCI, shown molecular mass of 17 kDa, as determined by SDSPAGE. 2D-PAGE showed four isoinhibitors with pI values of 4,42, 4,63, 4,83 and 5,06, with molecular mass of 17 kDa each. The aminoacid sequence of EvCI was determined by MALDI-TOF-MS and showed a high similarity with other Kunitz-type inhibitor of Erythrina variegata. EvCI competitively inhibited chymotrypsin, with Ki of 4 x10-8 M, but did not inhibited trypsin, pancreatic elastase, bromelain and papain. The inhibitory activity of EvCI was stable over wide pH and temperature ranges. In the presence of DTT 100 mM for 120 min, EvCI lost 50 % of activity. Cytotoxicity was studied in HeLa, MDA, HepG2, K562 and PC3 cells after 72-h incubation period. EvCl inhibited HeLa cells growth with an IC50 value of 50 μg/ml. Subsequent studies in HeLa cells analysis of cell death by annexin V/PI double-staining and cell cycle, using flow cytometry. The results provide evidence for a cytostatic activity of EvCl and support further studies on potential application of this inhibitors as an antiproliferative agent in combined therapy against cervical cancer

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The seeds are excellent sources of proteinase inhibitors and have been highlighted owing to various applications. Among these applications are those in effect on food intake and weight gain that stand out because of the increasing number of obese individuals. This study evaluated the effects of trypsin inhibitor present in the seed of tamarind (Tamarindus indica L.) reduction in weight gain, biochemical and morphological alterations in Wistar rats. For this, we partially purified a trypsin inhibitor tamarind seed. This inhibitor, ITT2 at a concentration of 25 mg / kg body weight, over a period of 14 days was able to reduce food intake in rats (n = 6) by approximately 47%, causing a reduction in weight gain approximately 70% when compared with the control group. With the evaluation of the in vivo digestibility was demonstrated that the animals lost weight due to satiety, presented by the reduction of food intake, since there were significant differences between true digestibility for the control group (90.7%) and the group treated with inhibitor (89.88%). Additionally, we checked the deeds of ITT2 on biochemical parameters (glucose, triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, glutamic-pyruvic transaminase, glutamic oxaloacetic transaminase, gamma glutamyl transferase albumin, globulin, total protein and C-reactive protein) and these, when assessed in the study groups showed no statistically significant variations. We also evaluate the histology of some organs, liver, stomach, intestine, and pancreas, and showed no changes. And to evaluate the effect of trypsin inhibitor on food intake due to the satiety is regulated by cholecystokinin (CCK) were measured plasma levels, and it was observed that the levels of CCK in animals receiving ITT2 were significantly higher ( 20 + 1.22) than in animals receiving only solution with casein (10.14 + 2.9) or water (5.92 + 1.15). Thus, the results indicate that the effect caused ITT2 satiety, reducing food intake, which in turn caused a reduction in weight gain in animals without causing morphological and biochemical changes, this effect caused by the elevation of plasma levels CCK

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The development of new materials to fill the demand of technological advances is a challenge for many researchers around the world. Strategies such as making blends and composites are promising alternatives to produce materials with different properties from those found in conventional polymers. The objective of this study is to evaluate the effect of adding the copolymer poly(ethylene methyl acrylate) (EMA) and cotton linter fibers (LB) on the properties of recycled poly(ethylene terephthalate) (PETrec) by the development of PETrec/EMA blend and PETrec/EMA/LB blend composite. In order to improve the properties of these materials were added as compatibilizers: Ethylene - methyl acrylate - glycidyl methacrylate terpolymer (EMA-GMA) and maleic anhydride grafted polyethylene (PE-g-MA). The samples were produced using a single screw extruder and then injection molded. The obtained materials were characterized by thermogravimetry (TG), melt flow index (MFI) mensurements, torque rheometry, pycnometry to determinate the density, tensile testing and scanning electron microscopy (SEM). The rheological results showed that the addition of the EMA copolymer increased the viscosity of the blend and LB reduces the viscosity of the blend composite. SEM analysis of the binary blend showed poor interfacial adhesion between the PETrec matrix and the EMA dispersed phase, as well as the blend composite of PETrec/EMA/LB also observed low adhesion with the LB fiber. The tensile tests showed that the increase of EMA percentage decreased the tensile strength and the Young s modulus, also lower EMA percentage samples had increased the elongation at break. The blend composite showed an increase in the tensile strength and in the Young`s modulus, and a decrease in the elongation at break. The blend formulations with lower EMA percentages showed better mechanical properties that agree with the particle size analysis which showed that these formulations presented a smaller diameter of the dispersed phase. The blend composite mechanical tests showed that this material is stronger and stiffer than the blend PETrec/EMA, whose properties have been reduced due to the presence of EMA rubbery phase. The use of EMA-GMA was effective in reducing the particle size of the EMA dispersed phase in the PETrec/EMA blend and PE-g-MA showed evidences of reaction with LB and physical mixture with the EMA

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulphate fractionation, affinity chromatography on immobilized Trypsin-Sepharose and TCA precipitation. The trypsin inhibitor, named ITC, had Mr of 32.5 kDa by SDS-PAGE and was composed by two subunits with 27.7 and 5.6 kDa linked by disulphide bridges, a typical characteristic of Kunitz-Inhibitor family. ITC was stable until 50°C, and at 100°C its residual activity was of about 60%. Also, ITC was stable at pHs 2 to 12. The inhibition of trypsin by ITC was non-competitive, with a Ki of 8,8 x 10-7M. ITC inhibits weakly other serine proteinases such as chymotrypsin and elastase. The inhibition of papain (44% of inhibition), a cysteine proteinase was an indicative of the bi-functionality of ITC. In vitro assays against digestive proteinases from several Lepdoptera, Diptera and Coleoptera pests were made. ITC inhibited in 100% digestive enzymes of Ceratitis capitata (fruit fly), Spodoptera frugiperda and Alabama argillacea, the last one being a cotton pest. It also inhibited in 74.4% Callosobruchus maculatus (bean weevil) digestive enzymes, a Coleoptera pest. ITC, when added in artificial diet models, affected weakly the development of C. capitata larvae and it had a WD50 of 2.65% to C. maculatus larvae

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Serines proteinases inhibitors (PIs) are widely distributed in nature and are able to inhibit both in vitro and in vivo enzymatic activites. Seed PIs in than leguminous are classified in seven families, Bowman-Birk and Kunitz type families that most studied representing an important role in the first line of defense toward insects pests. Some Kunitz type inhibitors possess activities serine and cysteine for proteinases named bifunctional inhibitor, as ApTKI the inhibitor isolate from seed of Adenanthera pavonina. The A. pavonina inhibitor presenting the uncommon property and was used for interaction studies between proteinases serine (trypsin) and cysteine (papain). In order to determinate the in vitro interaction of ApTKI against enzymes inhibitor purification was carried cut by using chromatographic techniques and inhibition assays. The 3D model of the bifunctional inhibitor ApTKI was constructed SWISS-MODEL program by homology modeling using soybean trypsin inhibitor (STI, pdb:1ba7), as template which presented 40% of identity to A. pavonina inhibitor. Model quality was evaluated by PROCHECK program. Moreover in silico analyzes of formed complex between the enzymes and ApTKI was evaluated by HEX 4.5 program. In vitro results confirmed the inhibitory assays, where the inhibitor presented the ability to simultaneously inhibit trypsin and papain. The residues encountered in the inhibitor model of folder structural three-dimensional that make contact to enzymes target coud explain the specificity pattern against serine and cysteine proteinases

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Oilseeds are a high-value natural resource, due to its use as a substitute for petroleum. However, the storage time can reduce seed viability and oil quality. Therefore, scientific efforts have been made to provide a increment of storage time, germination rates and plant establishment of high-value oilseeds. The seedling establishment depends of the plant pass over the functional transition stage, characterized by a metabolic change from heterotrophic condition to autotrophic one. The storage oil mobilization is performed by β-oxidation process and the glyoxylate cycle. Also, the functional transition involves acclimation to photosynthetic condition, which generally includes the participation of antioxidant system and the reactive oxygen species, the latter are produced in various reactions of primary and secondary metabolism. In the present study, Catalase was inhibited during the functional transition of sunflower and safflower, after were performed many analyzes to elucidate the effects caused on the SOD and APX antioxidant systems. Also, were checked the changes in expression pattern of the glyoxylate cycle enzymes markers, ICL and MLS. It was observed that after CAT inhibition, the SOD and APX antioxidant systems allow the seedling establishment. Besides, was verified that both oilseeds can be accelerate the reverse mobilization and the photosynthetic establishment when Catalase activity has dramatically decreased

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The brazilian-plum (Spondias tuberosa, His) is a tropical fruit tree that has been consolidated in the market for agribusiness processing, due to its characteristic flavor of fruit. Accordingly, studies to optimize the propagation of plants are necessary for production of seedlings with agronomic and quality assurance measures. This study aimed at determining the efficient techniques for uniform seed germination, as brazilian-plum seed present mechanical dormancy, and establish optimal culture media for multiplication of shoots from the in vitro micropropagation. Firstly, in a greenhouse at the Universidade Federal do Rio Grande do Norte, was evaluated the influence of different methods of breaking dormancy in the emergence of seedlings of brazilian-plum and speed of germination (IVG) of seeds. After 60 days of cultivation, it was found that splay in the distal portion of the seed was the best treatment, with rates of 85.33% in germinability and 3.415 of IVG, compared with the treatment of seed-soaking in water for 12h + humus and the control group. Subsequently, new sources of seedling explants were obtained in studies of tissue culture. Laboratory of Plant Biotechnology that the university, was used stem apex, nodal segments and internodes in search of decontamination with various concentrations of calcium hypochlorite [Ca(OCl)2] and micropropagation, inoculating them in half WPM (1980) with various concentrations of 6-benzylaminopurine (BAP). We used 10 sample units with three replications for different concentrations of [Ca(OCl)2], BAP and explants type. After thirty days, which was observed for the control of contamination, during the establishment in vitro, concentrations of [Ca(OCl)2] between 0.5% and 2.0% were effective in combating exogenous contamination of the apex. In nodal segments and internodes, concentrations of [Ca(OCl)2] between 1.0% and 2.0% and 1.5% and 2.0% were respectively, sufficient to reduce the percentage of losses in these infestations explants. For micropropagation, the culture medium supplemented with 0.1 mg.L-1 BAP promotes better development of multiple shoots per explants from nodal segment. However, success does not get to shoot training in internodal segment

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Although it has been suggested that retinal vasculature is a diffusion-limited aggregation (DLA) fractal, no study has been dedicated to standardizing its fractal analysis . The aims of this project was to standardize a method to estimate the fractal dimensions of retinal vasculature and to characterize their normal values; to determine if this estimation is dependent on skeletization and on segmentation and calculation methods; to assess the suitability of the DLA model and to determine the usefulness of log-log graphs in characterizing vasculature fractality . To achieve these aims, the information, mass-radius and box counting dimensions of 20 eyes vasculatures were compared when the vessels were manually or computationally segmented; the fractal dimensions of the vasculatures of 60 eyes of healthy volunteers were compared with those of 40 DLA models and the log-log graphs obtained were compared with those of known fractals and those of non-fractals. The main results were: the fractal dimensions of vascular trees were dependent on segmentation methods and dimension calculation methods, but there was no difference between manual segmentation and scale-space, multithreshold and wavelet computational methods; the means of the information and box dimensions for arteriolar trees were 1.29. against 1.34 and 1.35 for the venular trees; the dimension for the DLA models were higher than that for vessels; the log-log graphs were straight, but with varying local slopes, both for vascular trees and for fractals and non-fractals. This results leads to the following conclusions: the estimation of the fractal dimensions for retinal vasculature is dependent on its skeletization and on the segmentation and calculation methods; log-log graphs are not suitable as a fractality test; the means of the information and box counting dimensions for the normal eyes were 1.47 and 1.43, respectively, and the DLA model with optic disc seeding is not sufficient for retinal vascularization modeling

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dormancy is an inherent property of the seeds that define the environmental conditions in which they are able to germinate and their presence is an adaptive trait common in species inhabiting semiarid regions. Moreover, the ability of seedling establishment in these environments has been related to the size, strength and chemical characteristics of the seeds. This study investigated patterns of dormancy and germination speed in tree species of the Caatinga, exploring how the seed size influence the processes of germination, seedling size and biomass allocation. In addition, we aim to investigate the chemical characteristics of the reserves, to verify a possible relationship between nutritional content and the process of seed germination. Therefore, seeds were collected from ten species of woody Caatinga for tests of breaking dormancy, germination and biochemical characterization. Overall, the results show that the scarification treatments mechanical and chemical, and thermal shock influenced the percentage and speed of germination in 50 % of the species, suggesting that they have some level of physical dormancy in the seeds. Biochemical characterization showed the existence of large amounts of carbohydrates in the seeds of all species, low proportion of protein and low amounts of neutral lipids. Using linear regression, we demonstrated the existence of a significant relationship between seed size and the ratio of root/shoot where the largest seeds invested a greater amount of resources for shoot growth. The relationship between germination speed and non-reducing sugar content was also significant, so these compounds is related to the maintenance of physiological seed quality. These results confirm some relationships discussed in the literature for cultivated species, but can be applied to the species native to the Caatinga