Intraspecific variability of Holostylis reniformis: concentration of lignans, as determined by maceration and supercritical fluid extraction (SFE-CO2), as a function of plant provenance and plant parts

Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. ¹H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO2 were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated.

Inorganic phosphates in juices from different parts of sugarcane stalks (cultivars ctc 9, ctc 15 and ctc 16)

This study aimed to quantify, the inorganic phosphates in sugarcane juice from nodes and internodes of three sugarcane cultivars. The experimental design was a randomized block in factorial scheme 3x2. The main treatments were three sugarcane cultivars and two parts of the stalk (nodes and internodes). The inorganic phosphates contents were determined for each treatment. The results were subjected to variance analysis by the F test; when statistically significant, means were compared by the Tukey test at 5% probability. It is concluded that the three cultivars (CTC 9, CTC 16 and CTC 15) showed similar values regarding the content of inorganic phosphates present in the juice, and these values are considered adequate for a good performance in juice clarification. For the different parts of the stem, differences were observed in the levels of the nutrient studied, which showed a higher concentration in the node than in the internode.

Evaluation of the acidity in the juice from different parts of the stem of sugarcane, cycle 2010/2011

The acidity levels present in the juice of sugarcane can cause problems in its processing. This study aimed to compare the values of total, volatile and fixed acidity in the juice of the stem nodes and internodes of sugarcane. The experimental design was a completely randomized, 3x2 factorial arrangement with four replications, using three varieties of sugarcane (IAC91-1099; ISC95 and CTC7-5000) divided into node and internode. The stems were collected and separated in node and internode. After extraction of juice from each part, total, volatile and fix acidities were determined. The results were subjected to variance analysis the by F test and compared by the Tukey test at 5% probability. The cultivar CTC7 had the lowest levels of total and fixed acidity. Cultivar IAC91-1099 showed high levels of fixed acidity on both parts of the stem, and high volatile acidity at the node. In the stem, the values of volatile acidity showed no definite pattern between cultivars. The node has, in general, a higher fixed acidity, but some cultivars have shown opposite results.

Processamento de peças em materiais compósitos para o projeto BAJA SAE

The weight of a vehicle has always been considered an extreme important factor, because it interferes in the performance, steering, consume, environmental impact, wear of components, among the others. Because of the new demand, consume reduction aim and gases emission increased the necessity to manufacture lighter vehicles, guaranteeing the complying with the gas emission international law. Besides the legal demand, the low weight will certainly be essential for the competitiveness for the next generation of vehicles. It is with this thinking the composite materials have been introduced in the automobilist industry, because those materials show an excellent relation of strength/weight, providing a reduction of consume and the increase of load capacity. Those factors justify the increase of interest of industry and the necessity of optimization of those materials and of their process. For this research, the field of application will be the Baja SAE Project, a project that is fully developed by engineering students, where they build a prototype single seat, off-road category, for use on hilly slopes with obstacle. This research aims to study two key components of the prototype are made of composite materials, analyzing all the processing. In addition, there is the analysis of the viability of this production parts to a Baja SAE vehicle, in order to increase their performance and reduce their weight without reducing the safety and robustness of the prototype. It was possible to achieve weight reduction of the steering subsystem with manufacturing the flywheel hybrid composite (carbon/glass) and the replacement of SAE 1010 steel by hybrid composite (carbon/aramid) in CVT box. The importance of this study is to obtain a good project for the vehicle of technical and scientific manner, contributing to the know-how to the team and providing a basis for optimization for upcoming projects

Aplicação de adesivos estruturais em painéis de carros

The automobile industry is increasingly interested in reducing vehicle weight for greater speed, lower fuel consumption and emissions, through innovation of materials and processes. One way to do this is to seek the replacement of conventional processes by the use of structural adhesives. Structural adhesives are highly resistant materials, which can replace rivets, bolts and welds allowing the substrate / adhesive assemble is stronger than the substrate itself. One of the major advantages of gluing with respect to welding is its esthetic appearance, since it does not leave marks. For this reason, parts to be soldered require a minimum thickness so that the marks do not appear, since the pieces from gluing have no restriction as to the thickness. By replacing the vibration welding process for gluing process of the instrument panel parts of an automobile, one obtains a reduction of the thickness of the parts and therefore it decreases the weight of the car. This work aims to study the various structural adhesives that already exist on the market to be applied on the instrument panel. The mechanical test performed to measure the maximum adhesive strength was the Lap Shear Test at 23°C (room temperature), -35°C and 85°C. The types of adhesives used were the hot-melt and the bi-component. By the results obtained, it is in favor using the bi-component for application to the union of instrument panel parts

Analise de desgaste em materiais aplicados em discos de freio

Baja SAE competitions challenge engineering students to design and build offroad vehicles, preparing them for the competitive job market. This monograph aims to study a part of the braking of a Baja SAE vehicle system, the brake disc. Giving attention to the wear suffered by discs of two different materials, steel 1045 and stainless steel 304, helping the team Piratas do Vale Bardahl in the best selection between them. Braking tests were performed on a test bench. Both discs have suffered the same braking conditions. Brake pads material, brake line pressure, braking time, number of braking, were parameters which were repeated in the testing of different types of disk, in order to ensure a high power comparison between the obtained data. Before and after the disk tests were weighed and measured, to make a comparison. After the brake tests, the disks were subjected to hardness and surface roughness testing. With the data collected and observations made in the worn parts, the comparison between these two materials was made, obtaining a selection of the best material for the team. The tests showed that steel 1045 has more advantages, compared to stainless steel 304, when applied to brake discs, on the tested conditions

Avaliação da usabilidade de representações cartográficas em diferentes escalas para sistema de navegação e guia de rota em automóvel

Pós-graduação em Ciências Cartográficas - FCT

The association of chlorhexidine digluconate and calcium chloride to use as vehicle of a silicate calcium-based cement

Objective: The purpose of this study was to evaluate the influence of the addition of 2% chlorhexidine digluconate (CHX) associated with 5% calcium chloride (CaCl2 ) on antimicrobial activity, setting time, pH and calcium release of gray mineral trioxide aggregate (GMTA). Materials and Methods: GMTA powder was mixed with water, 2% CHX alone or 2% CHX combined with 5% CaCl2 . Antimicrobial activity was determined against Enterococcus faecalis (ATCC 29212) strains by agar diffusion test. Data obtained were submitted to kruskal wallis tests. Analysis of the setting time was evaluated by American society for testing and materials C266-03 requirements. The pH and calcium release analysis were evaluated, in 24 h, 7, 14 and 28 days using pH meter equipment and atomic absorption spectrophotometer, respectively. Data obtained were analyzed by ANOVA, in 5% significance level. Results: Significant differences were seen (P < 0.01) among the zones of bacterial growth inhibition produced by 5% CaCl2 + 2% CHX combination against E. faecalis when compared with water (P < 0.05). Regarding the setting time, that combination had the shortest setting time (P < 0.05). All associations were alkaline and released calcium. No statistical difference was observed between the experimental groups at the different periods of analysis (P > 0.05). Conclusion: Combination of 5% CaCl2 + 2% CHX reduced the setting time and enhanced the antimicrobial activity of GMTA without changing the pH and calcium release.

Avaliação dos mecanismos de endurecimentoda liga AISI 300M submetida a diferentes ciclos de transformações martensíticas

Pós-graduação em Engenharia Mecânica - FEG

Action of ethanolic extract from aerial parts of Tagetes patula L. (Asteraceae) on hatchability and embryogenesis of Rhipicephalus sanguineus eggs (Acari: Ixodidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Late Quaternary vegetation dynamics from central parts of the Madeira River in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

An MILP model for the plug-in electric vehicle charging coordination problem in electrical distribution systems

A new mixed-integer linear programming (MILP) model is proposed to represent the plug-in electric vehicles (PEVs) charging coordination problem in electrical distribution systems. The proposed model defines the optimal charging schedule for each division of the considered period of time that minimizes the total energy costs. Moreover, priority charging criteria is taken into account. The steady-state operation of the electrical distribution system, as well as the PEV batteries charging is mathematically represented; furthermore, constraints related to limits of voltage, current and power generation are included. The proposed mathematical model was applied in an electrical distribution system used in the specialized literature and the results show that the model can be used in the solution of the PEVs charging problem.

Mutagenicity profile of atmospheric particulate matter in a small urban center subjected to airborne emission from vehicle traffic and sugar cane burning

Atmospheric particulate matter (PM) is genotoxic and recently was classified as carcinogenic to humans by the International Agency for Research on Cancer. PM chemical composition varies depending on source and atmospheric conditions. The Salmonella/microsome assay is the most used mutagenicity test and can identify the major chemical classes responsible for observed mutagenicity. The objective of this work was to characterize the mutagenicity of PM samples from a countryside city, Limeira, Brazil, which is influenced by heavy traffic and sugar cane biomass burning. Six samples of total PM were collected. Air mass backward trajectories were calculated. Organic extracts were assayed using the Salmonella/microsome microsuspension mutagenicity assay using TA98, YG1041, and TA1538, with and without metabolic activation (S9). YG1041 was the most sensitive strain and mutagenicity reached 9,700 revertants per m(3) without metabolic activation. Potency for TA1538 was higher than TA98, indicating that this strain should be considered in air mutagenicity studies. The increased response to YG1041 relative to TA98, and the decreased response with S9, suggests that nitroaromatics are the major contributors. Limeira is among the most mutagenic cities in the world. High mutagenicity in Limeira seems to occur when the air mass from the area of sugarcane production is mixed with air from the region impacted by anthropogenic activities such as traffic. An increase in the formation of nitro-polycyclic aromatic hydrocarbons may result from longer contact time between the aromatic compounds and the atmosphere with high NOx and ozone concentration, although more studies are required to confirm this hypothesis. Environ. Mol. Mutagen., 2015. © 2015 Wiley Periodicals, Inc.

Análise dos fatores influentes nos riscos de descontinuidade na cadeia de peças de reposição automotivas

Pós-graduação em Engenharia Mecânica - FEG

Leishmanicidal activity of different parts from Arrabidaea brachypoda (DC.) Bureau (Bignoniaceae)

Infections by protozoans of the genus Leishmania are the major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which exert renal and cardiac toxicity. Thus, there is a strong need for safer and more effective treatments against leishmaniasis. The present study was designated to evaluate, by a bioguided assay, the leishmanicidal activity of hidro-ethanolic extracts from different parts (leves, caule and root) of one same plant the Arrabidaea brachypoda (DC.) Bureau. Its has been used to relieve general pain, painful joints and kidney stones in Brazilian folk medicine. Nevertheless, scientific information regarding this species is scarce; there are no reports related to its possible leishmanicidal activity. The leves extract presented the best activity on promastigotes forms of Leishmania (L.) amazonensis, when compared to the other extracts. It showed significant activity on Leishmania (L.) amazonensis. Our results are promising, showing that these compounds are biologically active on Leishmania (L.) amazonensis.