Navegando por Data de Publicação, começando com "2020-06-22"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 6 de 6

Triagem de isolados clínicos de Leishmania sp. para sequenciamento genômico
(Universidade Federal de São Carlos, 2020-06-22) Takahashi, Talita Yuri; Maruyama, Sandra Regina Costa; https://lattes.cnpq.br/5719754923228879; https://lattes.cnpq.br/0742274098797121
Leishmaniasis is a group of infectious tropical disease caused by protozoan from genus Leishmania and transmitted to humans through bites of infected sand flies. Visceral Leishmaniasis (VL) is the most severe clinical form of the disease and can be lethal if untreated or treatments fail. Brazil composes one of the 13 countries with the highest number of new VL cases in the world caused by Leishmania infantum, with a great focus on Northeastern. Treatments are poorly developed and the fatality rate expands every year affecting mainly children under 10 years-old. Recent study has shown the occurrence of a similar Crithidia fasciculata parasite in clinical isolates (LVH60 and LVH60a) in a fatal VL case. The disease onset is related to parasite/host interface factors. Parasite identification and genomic analyses of the pathogen enable to understand the intrinsic factors and genetic diversity of parasite related to the disease outcome and response to treatment. Thus, one of the aims in this study was to perform the screening of clinical isolates from patients diagnosed with VL in Aracaju - Sergipe region, to select samples for Whole-Genome Sequencing (WGS) in Illumina platform for obtaining complete genomic sequences of parasites capable of causing VL in this endemic area. The screening encompassed the parasite morphological analysis, molecular characterization of conserved genomic regions through DNA sequencing analysis and molecular phylogenetics. Engendered data were useful for constructing an informative panel about the analyzed samples, which guided to the selection of clinical isolates for genome sequencing. In parallel, this study also had as aim to systematize the genome analyzes of WGS data obtained from previous work, which will assist the Comparative Genomic analyses between Leishmania and Crithidia-like to our group’s further studies. Finally, a polished genome of Crithidia-like parasite was obtained from a clonal sample of LVH60a with Oxford Nanopore Technology (ONT), which resulted in a final genome assembly of 38 contigs and a predicted genome size of 34.4 Mb in length. This study was essential to understand the occurrence of non-Leishmania parasites in the endemic region of LV in Aracaju and for studying the genome and genetic variation to lead future strategy analyses and intervention in public health caused by this new parasite.
Obstacle detection and avoidance for a mobile robot
(Universidade Federal de São Carlos, 2020-06-22) Silva, Rafael Gomes da; Roberto, Santos Inoue; https://lattes.cnpq.br/6221209121565990; Amar, Faiz Ben; ; https://lattes.cnpq.br/7347910207598781
Off-road robots are complex vehicles used in a variety of applications and are capable of operating over rough terrain, and its application has been growing more and more nowadays. With the growing importance of the study and application of autonomous vehicles in rough areas for the users’ safety reasons, researches concerning this kind of vehicle have increased. Works were already done to propose algorithms for non-linear predictive controllers, for the improvement of the stability of the vehicle, for path following and also for a nonlinear observer to estimate the contact cornering stiffness in real-time, but there is also the question of how to proceed if the robot encounters an obstacle that could obstruct its path while it is tracking a path. Thus, this work aims to propose an algorithm that allows a four-wheel, fast off-road, double-steering mobile robot to detect obstacles from the terrain in real-time using the dynamic mapping of the environment, and that also allows the robot to avoid obstacles by following a local path created using a composite Bézier curve, optimized based on the maximum steering that the robot can perform. For the experiments, a sensor for position and perception were used, including the Lidar (Light Detection And Ranging) Velodyne HDL-32E. The treatment of the point cloud provided by it was treated using mainly the PCL library. For reasons of internship duration, the tests performed were done mostly in a virtual environment considering different types of trajectory to be followed by the SPIDO, with obstacles positioned along the way. The final results obtained were satisfactory concerning the expected, thus concluding the validity of the proposed algorithm.
Influência da variação de parâmetros da técnica de fusão seletiva a laser na microestrutura e dureza da liga reciclada Al-Fe-Cr-Ti formadora de fase quasicristalina
(Universidade Federal de São Carlos, 2020-06-22) Micheloti, Leandro César; Araújo, Aylanna Priscila Marques de; Gargarella, Piter; https://lattes.cnpq.br/4641435644243916; https://orcid.org/0000-0003-4445-5819
Selective laser melting (SLM) is an additive manufacturing technique that has attracted increasing interest due to the possibility of creating products with complex geometries and customizable density, which could not be produced by traditional processes, such as machining and casting. This technique also allows the achievement of high cooling rates during processing (~105 K/s), which favors the formation of metastable phases. Numerous parameters influence the parts produced by SLM, including power, speed, and the type of material being processed. Quasicrystalline alloys have the ability to precipitate the quasicrystalline (QC) phase under certain processing conditions. The QC phase is a metastable phase characterized mainly by presenting high hardness and brittleness, which requires high cooling rates to precipitate and is usually only obtained in powders and ribbons. SLM is a promising technique for quasicrystalline alloys due to the high cooling rates that are achieved, allowing the formation of the QC phase in bulk products. When the QC phase precipitates in aluminum alloys, it acts as a reinforcement phase of the ductile matrix α-Al, increasing the mechanical strength at high temperatures and the wear resistance of the alloys. Applications in molds and parts for automotive and aeronautical engines are some examples of where these alloys can be applied. The production of quasicrystalline alloys has been carried out using pure elements, however, it is well known the importance of using recycled materials. Taking these considerations, the aim of this work was to investigate the influence of some SLM parameters on the microstructural, thermal, and mechanical characteristics of the recycled quasicrystalline phase-former Al95Fe2Cr2Ti1 alloy. The effects of scanning speed, hatching, sample size, and heating substrate were evaluated regarding to finishing surface, the morphology of the melting pools, content and morphology of the quasicrystalline phase formed and also in the microhardness of the samples. The parts produced were characterized by X-ray diffraction, differential scanning calorimetry, optical microscopy, scanning electron microscopy, density, and microhardness. The results indicated the presence of the quasicrystalline phase in all samples produced by SLM. The density of the samples was not significantly changed with the tested parameters. Higher content of QC phase was obtained for samples produced with higher scanning speed. The morphology of the melt pools was influenced by both scanning speed and hatching. The surface cracks were more evident in the samples constructed with a larger size, however, the increase in the substrate temperature indicated an alternative to reduce this type of defect.
Machine learning em química orgânica
(Universidade Federal de São Carlos, 2020-06-22) Chiavegatti Neto, Attilio; Ferreira, Marco Antonio Barbosa; https://lattes.cnpq.br/6874055640224407; https://lattes.cnpq.br/5550113177749315
The search for intelligent computational systems capable of solving problems that are traditionally reserved for the human mind are a long-standing crusade. Several attempts to solve problems such as structural identification and synthesis of organic molecules using those toolboxes started in the 1970s, but the low capacity of available computational power and the lack of appropriate algorithms at the time were severe limitations, rendering many of these projects unfeasible. Currently, with a continuous increase in the processing capacity and with an enormous amount of chemical information accumulated in public and commercial databases, the interest in developing these systems has resurged. Several papers that have been published show that using machine learning algorithms it is possible to create programs capable of automatically generate synthetic paths for complex molecules of industrial and academic interest and also optimize reactions in an efficient and autonomous way.
Projetos de dosadores mecânicos e pneumáticos para a semeadura mecanizada de amendoim
(Universidade Federal de São Carlos, 2020-06-22) Angelo, Eduardo Prisco; Voltarelli, Murilo Aparecido; https://lattes.cnpq.br/4889939917847330; https://lattes.cnpq.br/6965502961463356
A crop of peanuts (Arachis hypogaea L.) is providing important gains for the country. However, although there has been an increase in the area sown in the country over the years, the need to increase also increases. For this, the development of mechanisms for specific use for culture is of great importance, since the use of standard dials for culture can favor mechanical injuries and failures in seed exposures. In this context, the objective of this work was to design two peanut seed engines. With a characterization of the linear and physical parameters of the seeds, it was possible to determine the mechanics of filling the discs for the honeycomb disk, and with the data of sowing densities (12; 15; 17 and 20 seeds m-1) with frequency of seed displacement. machine (4.00; 5.00 and 6.00 km h-1) determined a negative pressure in the pneumatic system. According to the analysis of the packing mechanics of the alveoli, the tangential speed of the base or alveolar disk must contain to dose as the three varieties were 43.65 rpm. On the other hand, with the determination of the negative pressure it was possible to verify that there is a variation of approximately 10.4 kPa of pressure between the lowest and the highest average speed of 4.0 km h-1 in relation to the number of seeds per meter , for working speeds of 5.0 and 6.0 km h-1 as media variations were 16.4 and 22.7 kPa, respectively. In this way, the standards used for dimensioning the mechanisms were dimensioned linear and an area designed for seeds. The processors' engines did not elaborate any AutoCAD® software and those printed using a 3D printer.
Propagação e controle de Anredera cordifolia (Ten.) Stennis
(Universidade Federal de São Carlos, 2020-06-22) San Gregorio, João Paulo Ruvieri; Silva, Paulo Vinícius da; https://lattes.cnpq.br/9428251941902990; Monquero, Patricia Andrea; https://lattes.cnpq.br/2766526793830455; https://lattes.cnpq.br/0652406678640024
Anredera cordifolia (Ten.) Stennis (Madeira vine) is a succulent vine that produces vegetative structures on its stem, called aerial bulbils that are responsible for the dispersion of this species. This plant has become a possible invader in Brazilian agriculture with records of losses in coffee crops. The objective of this study was to study the influence of dimensional variation and different depths of planting aerial bulbils on the growth and development of A. cordifolia plants, as well as to study the influence of the effect of herbicides on pre and post emergence control of plants. All experiments were carried out in a greenhouse. Experiments for the study of propagation: In experiment 1, a completely randomized design with six replications was used. The treatments consisted of four mass classes (previously established) of aerial bulbils: C1 (0 to ≤ 0.6g), C2 (> 0.6 to ≤ 1.5g), C3 (> 1.5 to ≤ 3.0g) and C4 (> 3.0 to ≤ 12.0g), observing the percentage of viable bulbils (BV), the number of stems per bulbillus (NH/B), the average stem length (CMH), the aerial part dry mass (MSPA) and the emergency speed index (IVE). For experiment 2, a completely randomized design with four replications was used. The emission of plants by bulbilli planted at seven different depths (0, 3, 6, 10, 15, 20 and 30 cm) was verified, NH/B and IVE were observed. Experiments designed to study the management of potted plants: In experiment 1, the control percentage and the MSPA were determined after application in post-emergence in the commercial dose of the herbicides: chlorimuron-ethyl (20 g a.i. ha-1), flumioxazin ( 25 g a.i. ha-1), glyphosate (2.4 g a.i. ha-1), metsulfuron-methyl (6 g a.i. ha-1), saflufenacil (70 g a.i. ha-1) and glyphosate + saflufenacil (1.44 g a.i. ha-1 + 49 g a.i. ha-1) in a completely randomized design in a factorial scheme (herbicides X periods), with four replications. In experiment 2, the number of shoots per bulb (NB/B) was observed after the application of the herbicides: flumioxazin (120 g a.i. ha-1), imazapic (122.5 g a.i. ha-1), indaziflan (92.5 g a.i. ha-1), metribuzin (960 g a.i. ha-1), sulfentrazone (700 g a.i. ha-1) and tebuthiuron (1200 g a.i. ha-1) in pre-emergence of the plants in a completely randomized design, with four replications. Plants from bulbils with greater mass have a fast growth and establishment; the establishment of aerial bulbils on the soil surface has a greater chance of emission of plants with rapid growth; A. cordifolia plants had about 80% control when subjected to the mixture of glyphosate + saflufenacil herbicides.