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Comportamento ecofisiológico de Croton urucurana Baill, Cecropia pachystachya Trécul, Gallesia integrifolia (Spreng.) Harms, Hevea brasiliensis Willd. Ex A. Juss e Psidium cattleianum Sabine
(Universidade Federal de São Carlos, 2020-05-20) Leal, Mariana Santos; Tonello, Kelly Cristina; https://lattes.cnpq.br/3844965971290638; https://lattes.cnpq.br/3208577997632374
The ecophysiological behavior of plants is intrinsic to each plant species and is also influenced by environmental conditions such as solar radiation and water availability. Once the ecophysiology of tree species and their interactions with environmental conditions and their water use efficiency are better understood, local water dynamics can be better understood and more efficient management systems adopted. The objective of this study was to characterize, quantify and compare the ecophysiological behavior (transpiration, photosynthesis and stomatal conductance) and the efficiency of water use as a function of environmental variables and soil water availability of five native forest species: Croton urucurana, Cecropia pachystachya, Hevea brasiliensis, Gallesia integrifolia and Psidium cattleianum. The monitoring of the ecophysiological variables was performed in the hour scale, in healthy and expanded leaves of seedlings packaged with the aid of the diffusion porometer, and the leaf water potential was obtained by means of the Scholander pump. The results indicated that the studied species responded differently to environmental conditions (water availability, photosynthetically active radiation and vapor pressure deficit), and in general, the seedlings of all species under conditions of lower leaf water potential had lower rates of gas exchanges, however on a different scale of values. Thus, the restriction of water in the soil caused the plants to decrease their rates in order to avoid excessive water loss.
Géis, nanocompósitos e compósitos de pectina preparados utilizando a técnica adaptada de ice template.
(Universidade Federal de São Carlos, 2020-05-20) César, Natália Reigota; De Meneses, Aparecido Junior; https://lattes.cnpq.br/0484426340349483; Waldman, Walter Ruggeri; https://lattes.cnpq.br/0616238673458322; https://lattes.cnpq.br/3615702921384821
Byopolymers, such as pectin, have the ability to form gels which allows their use as jelly thickeners in food industries, for example. Porous pectin gels are generally homogeneous, forming a water-rich mesh. Pores are cavities within a material, which in some cases can weaken it because it is a discontinuity, or its presence can favor its use in different applications. One of the techniques used for the production of porous materials is the ice template, or freeze-casting, which uses freezing to obtain these materials. The purpose of this work was to develop a process similar to the ice template, replacing the cold finger with cooling in a domestic freezer without a frost-free system; since this new methogology presents low cost and easy access. After the development of the technique, it was applied in the preparation of porous materials, the Project was developed using formulations of pectin and calcium below the concentration of gelation in diferente concentrations; as well as, nanocomposites were prepared with formulations of pectin, calcium and celulose nanofibril (CNF) also with concentrations below gelation; and finally, composites were prepared with diferente concentrations of pectin, calcium and fibers (obtained from young leaves of Typha domingensis) also with concentrations below gelation. After the satisfactory development of the adapted ice template system, followed by the preparation of the new materials, the selection of the best materials (gels, nanocomposites and composites) was carried out, these were conditioned to compression tests, in addition to being also morphologically characterized. The pre-selected solutions of gels and nanocomposites were tested on porous structures, thus forming pore structures within the pore, these were morphologically characterized; in order to possible application in cell growth. Among all the formulations prepared, after compression test (mechanical strength) and morphological characterization, the best mechanically obtained materials were the weak composites (improved 17,4 times in breaking strength compared to the weak gel), medium (improved 32,2 times in relation to the médium gel) and strong (improved 14,7 times in relation to the strong gel), the best formulation for the formation of pore structures within the pore was that of the gel called very weak, as this diffused porous material forming the expected structure.
Estudo comportamental e efeitos da interação animal-visitante dos felinos do Zoológico de São Paulo
(Universidade Federal de São Carlos, 2020-05-20) Mata, Emily Perez Guimarães da; Sekiama, Margareth Lumy; https://lattes.cnpq.br/7506297262479134; https://lattes.cnpq.br/9339760342899503
Zoos play the role of conservation, research, environmental education, and recreation centers, and one of their main concerns is the welfare of the animals on display, which can be influenced by factors such as adequate enclosure, balanced feeding, veterinary management and interaction with visiting public. The presence of visitors may influence animal behavior, either positively or negatively. Thus, understanding animal-visitor interaction is extremely helpful in the quest to improve the animals’ well-being and raise public interest, because it may help the species' conservation. Therefore, the general objective of this work was to analyze the crowd’s effect on the behavior of the cats at the São Paulo Zoo, and how the behavior of the cats affects the public's interest. 20 hours of behavioral observations were made for each species - Herpailurus yagouaroundi, Puma concolor, Panthera onca, Panthera leo, and Panthera tigris tigris - via focal animal sampling for enclosures with only one individual and scan sampling for enclosures with multiple animals. The recorded behaviors were then correlated to the visitors' behavior, age group, and length of stay in front of the venues. Furthermore, modifications were made to the structural and environmental elements of the H. yagouaroundi enclosure to verify the effect of these changes on the activity of the animals and the perception and interest of the public, and, following, new behavioral observations were made. The results showed that cats, in general, exhibited behaviors related to rest, such as lying down or remaining inactive in structures. The stereotyped behavior, pacing, was observed more frequently for the jaguar. As for other factors that could influence the cat’s behavior, such as the age range of the visitors and the time of the visit, they showed no effect, however, the pacing events occurred mainly during mornings. After the changes were made in the H. yagouaroundi enclosure, there was a reduction in the inactive and stereotyped behaviors of the species. Therefore, the enrichment of ex situ environments can be considered an important tool for zoos and institutions with animals under human care to promote the welfare of the animals, providing more complex environments so their behavioral repertoire can approach what is observed in their natural habitat. Also, the setting of the enclosures may promote greater attractiveness to the visiting public and consequently deeper knowledge, affection, and respect for the animals in captivity.
Método para classificação de sementes agrícolas em imagens obtidas por tomografia de raios-X em alta resolução
(Universidade Federal de São Carlos, 2020-05-20) Brito, André Ribeiro de; Cruvinel, Paulo Estevão; https://lattes.cnpq.br/7924553462118511; https://lattes.cnpq.br/8676076486184629
This research produced a method for classifying agricultural oil seeds based on tomography (CT) assays. Oilseeds may present good or poor quality for planting, the latter being related to the presence of defects associated with physical imperfections such as cracks, breaks and voids. In such a context, for the development of the method, high-resolution tomographic slices reconstruction have been considered, as well as the evaluation of digital image processing and visualization techniques, i.e., evaluations related to pre-processing, segmentation, extraction of supervised characteristics and classifiers. For such evaluations, samples containing oilseeds with and without defects for sunflower (Helianthus annuus L.), physic nut (Jatropha curcas L.), and soybean (Glycine max ( L.) Merrill) were classified. For the choice of the pre-processing, processing and visualization of tomographic images techniques, the following metrics were used: PSNR (Peak Signal-to-Noise Ratio), MSE (Mean Square Error), SSIM (Structural Similarity Index Measure), and DSC (Dice Similarity Coefficient). Thus, for the establishment of the method, the techniques for filtering and segmentation have been selected considering the Nonlocal means and Gaussian filters, while for the segmentation steps, the simple thresholding and graph techniques have been selected, respectively. For the characteristic extraction stage, the HOG (Histogram of Oriented Gradients) and the Hu invariant moments techniques have been selected, as they can allow obtaining texture descriptors and descriptors based on geometric characteristics, respectively. Additionally, the PCA (Principal Component Analysis) technique has been used to establish a composite characteristic vector with these descriptors. Finally, not only the NB (Naïve Bayes) but also the SVM (Support Vector Machine) classifier shown its usefulness. Furthermore, for the method, the NB classifier has been indicated for the analysis of tomographic slices of sunflower seeds and the SVM classifier for the analysis of tomographic slices of jatropha and soybean seeds. The method developed for the grading of oilseeds has been shown to be suitable for selection in pre-planting, which helps to assist decision making in the selection of good quality agricultural seed. It also contributes to the evolution of advanced techniques and analysis tools, obtained from digital image processing and visualization techniques.
Síntese e caracterização de nanopartículas de quitosana-tripolifosfato e seu potencial como antifúngico natural para aplicação por aspersão em frutas frescas
(Universidade Federal de São Carlos, 2020-05-20) Alexandrino, Taís Téo de Barros; Assis, Odílio Benedito Garrido de; https://lattes.cnpq.br/4626267791983725; https://lattes.cnpq.br/1423196539001121
Contamination by pathogens is a problem that occurs on a global scale and is related to approximately 25% of total fruit and vegetables losses in the post-harvest condition. The synthetic antimicrobials usually applied in order to minimize these losses, if not used in a moderate way, might generate undesirable impacts on human health and to the environment. So, a growing awareness and preference for healthy foods, absent of chemical pesticides, is in course. An alternative to meet these demands is the development of natural fungicides, which can act satisfactorily and with low impact or side effects. In this context, chitosan has been considered as a suitable alternative for the development of antimicrobials, mainly due its natural source and biodegradability. In conventional diluted form, chitosan has already proved to have a broad antimicrobial activity. In the present study, the synthesis of nanoparticles from the Chitosan-Tripolyphosphate (NPQui-TPP) system and their antifungal potential, when in aqueous suspensions, were evaluated in topical applications on fruits via spray. The premise is that as larger the particulate area, the greater will be the surface interaction between chitosan molecules and pathogens. The NPQui-TPP were synthesized by the ionotropic gelation method, and several experimental parameters evaluated aiming at the optimization and standardization of the process, where the following conditions were defined: height of 8 cm between intercrossing (TPP) dropping and the chitosan gel surface, under agitation of 1500 rpm and additional ultrasonication with 30% of amplitude for 2 minutes.In these conditions NPQui-TPP with an average diameter of 117.3 nm were generated and assessed in vitro at concentrations of 8 and 9 g/L with effective activity in inhibiting the growth of Alternaria alternata and Penicillium expansum inoculated in BDA medium. Formulations for topical application with 9 g/L (particles in suspension) were prepared and sprinkled on apples and guavas, inoculated and non-inoculated with the analyzed fungi, for in vivo assessment. Coatings in non-nanoparticulated condition (dipping into chitosan gel), were also carried out for comparison. The results show superior activities of NPQui-TPP when compared to the continuous coatings. The nanoparticulated coatings promoted reductions of 55 % in the loss of firmness in guavas and 38.7 % concerning the apples. Additionally the nanoparticles provided a decrease in 24 % in the fungal growth on apples and of 28 % on guavas, with simultaneous colorimetric alterations around 13.7 % on apples, when compared to non-coated samples, along 14 days. Although the exact mechanisms by which chitosan antimicrobial activity occurs is not yet fully elucidated, it is evident that chitosan in nanoparticles form has superior antifungal activity and general preservative properties, what have been attributed to their high surface area and consequently the ability to perform larger interactions.
Estudo de Ligas Fe-Nb-B Nanocristalinas Eutéticas Ultrafinas e Laser Cladding de Pós Atomizados
(Universidade Federal de São Carlos, 2020-05-20) Caneda, Chaiane Messa; Gargarella, Piter; https://lattes.cnpq.br/4641435644243916; Afonso, Conrado Ramos Moreira; https://lattes.cnpq.br/2176215981291453; https://lattes.cnpq.br/5288147854256960
Fe-Nb-B alloys have gained much attention in recent years because of the possibility to obtain different constituents in nanostructured composites, amorphous and ultrafine eutectics (scale of 100 nm to 1 μm) alloys depending on composition and cooling rate. These structures are originated by rapid solidification in non-equilibriun balance and have excellent mechanical (high hardness, high resistance to fracture and plasticity) and chemical properties. LASER processing is considered one of the routes that also allows the development of these structures, enabling new perspectives on technological applications of these alloys. This work presents aimed the development of ultrafine eutectic nanocrystalline Fe-Nb-B alloys seeking to evaluate the mechanical behavior on strength and ductility. From these selected compositions for the subsequent production of gas atomized powders were manufacturing the coatings of these alloys onto AISI 1020 mild steel substrate by LASER cladding using a pre-placed powder method. The compositions in which the coatings were produced, Fe76.5Nb8.5B15 and Fe74.25Nb8.25B17.5 (at. %), allowed to investigate the appropriate parameters ranges to obtain coatings with high microhardness and at the same time, with possible wear resistance. Both coatings were characterized using the techniques of X-ray Diffraction (DRX), Scanning (SEM) and Transmission Electron Microscopy (TEM) of a samples prepared by Focused Ion Beam (FIB) allowed the analysis of the formation of eutectic phases (as predicted).The wear resistance of coatings for Fe76.5Nb8.5B15 (at.%) alloy were evaluated through the pin-on-disk test with three-body abrasive indicated lower wear rates values compared to the steel substrate (1.9 x 10-5 to 3.9 x 10-5 mm³/Nm, respectively).