Passion fruit seed meal at growing and finishing pig (30-90 kg) feeding

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

Citrus pulp and enzyme complex for growing and finishing pigs

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

Hot turning of a difficult-to-machine steel (sae xev-f) aided by infrared radiation

A possible way for increasing the cutting tool life can be achieved by heating the workpiece in order to diminish the shear stress of material and thus decrease the machining forces. In this study, quartz electrical resistances were set around the workpiece for heating it during the turning. In the tests, heat-resistant austenitic alloy steel was used, hardenable by precipitation, mainly used in combustion engine exhaustion valves, among other special applications for industry. The results showed that in the hot machining the cutting tool life can be increased by 340% for the highest cutting speed tested and had a reduction of 205% on workpiece surface roughness, accompanied by a force decrease in relation to conventional turning. In addition, the chips formed in hot turning exhibited a stronger tendency to continuous chip formation indicating less energy spent in material removal process. Microhardness tests performed in the workpieces subsurface layers at 5 m depth revealed slightly higher values in the hot machining than in conventional, showing a tendency toward the formation of compressive residual stress into plastically deformed layer. The hot turning also showed better performance than machining using cutting fluid. Since it is possible to avoid the use of cutting fluid, this machining method can be considered better for the environment and for the human health.

Finishing precocity visual score and genetic associations with growth traits in Angus beef cattle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Color stability of a nanofilled resin: influence of polishing and finishing and fluoride solutions according to time

Aim: The aim of the study was evaluate the finishing and polishing effect of the color stability of the composite resin Filtek Supreme XT, according to different fluoride solutions and time. Material and Methods: Specimens were prepared (n=140) with half of the samples finished and polished. The experimental groups were divided according to the presence or absence of finishing and polishing and immersion solutions (artificial saliva, sodium fluoride solution at 0.05% - manipulated, Fluordent Reach, Oral B, Fluorgard). The specimens remained in artificial saliva for 24 hours and were subjected to an initial color analysis using a spectrophotometer CIELab system. Then, they were immersed in the experimental solutions for 1 minute a day. The readings of the color change were made after 24 and 48 hours, 7, 14, 21, 30 and 60 days after the first immersion. The three-way mixed Analysis of Variance (ANOVA) ("finishing/polishing", "immersion medium" and “time”) were performed. For multiple comparisons, the Sidak test for repeated measure was used, with a 5% level of significance. Results: The finishing and polishing factor showed significant variability, independently of the immersion media (p<0.001). Cconclusion: Finishing and polishing procedures yielded better color stability to composite resin over time, regardless of the immersion media.

Chemical and morphological features of nanofilled composite resin: influence of finishing and polishing procedures and fluoride solutions

This study evaluated the influence of finishing and polishing procedures and differ-ent fluoride solutions on superficial morphology and chemistry of the nanofilled composite resinSupreme XT (3M) through the EDX analysis and SEM evaluation. Circular specimens (n 5 30) of 10mm diameter and 2 mm thickness were prepared, with half of the sample assays finished and polishedwith Super-Snap1sandpaper. The experimental groups were divided according to the presence or ab-sence of finishing and polishing and solutions (arti ficial saliva, 0.0 5% of manipulated sodium fluoridesolution, Fluordent Re ach, Oral B, Fluorgard). Specimens were immersed in each respective solutionfor 1 min per day, during 60 days and stored in artificial saliva at 37 6 18C between immersion peri-ods. Topography and chemical analysis was qualitative. It was observed that specimens submitted tofinishing and polishing procedures had lower superficial degradation. Fluoride solutio ns promoted su-perficial alterations on specimens, being the highest degradation obtained with Fluordent Reach. Itca n be concluded that finishing and polishing procedures and the immersion media influence the su-perficial morphology of composite resin tested; the Fluordent Reach was the flu oride solution thatmo st affected the material’s surface.

Effect of finishing and polishing on color stability of a nanofilled resin immersed in different media

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Source and frequency of dry season lipid supplementation of grazing, finishing cattle

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

Análise do acabamento superficial e força de corte no torneamento de alumina a verde

In experimental conditions, cutting forces were studied during turning of green alumina billets, including their correlation with surface aspects of the workpiece. The correlation between cutting power and the removal rate are important parameters for defining the design of ceramic products, since inadequate parameters can produce excessive surface damage to the workpiece. This study examined the forces obtained during turning of alumina workpieces with 99.8% purity in their green state, by means of a three-point dynamometer, evaluating the cutting, feed and depth forces, using a cermet tool under constant machining conditions. Variables were compared with the forces, including surface finish, tool wear and temperature during machining. In the study, it was found that the depth of cut had no significant effect on the surface quality, and the cutting speed and feed influencing the finish. However, preliminary tests for selecting the cutting conditions showed that unsuitables cutting speeds and feeds generate severe damage to the workpiece surface. The best condition was 1.00 mm depth of cut, and the forces increasedfor with each pass performed, with the feed force the variable with greatest increases in relation to the cutting and depth forces, and wear of the cutting tool directly influenced the surface finish, generated by the highly abrasive nature of the alumina particles of the green compact. It is emphasized that the alumina in its green state showed high abrasive effect on the cutting tool during the turning process and the surface finishing of the green workpiece had a direct influence on the sintered workpiece.

Torneamento da liga de alumínio da classe 6005 utilizando ferramenta cerâmica

Machining processes are one of the most important manufacturing processes in the modern world. In these processes, there are many elements which will influence in the final result of the machined part. Among them, the tools are the principal factor of the rising cost, because its global influence on the process. In aeronautical industries, this can be more evidenced due the need to machining several alloys, between them, aluminum alloys. These alloys have to demonstrate a specific surface finishing to be used in aircraft's fuselage. This kind of industry is one of the segments which is still rising in Brazil, and they are looking viable alternatives in the manufacturing processes of materials, due the need to produce more and more parts and equipment, with costs increasingly reduced. The purpose of this project is the development of a ceramic with differentiated properties. The ceramics were developed using a pre-sintering at 1200 °C, with posterior sintering at 1600°C, and subjected to dry turning process on aluminum alloy 6005. The characterizations showed that ceramics presented with toughness on the center of 1700 MPa and on the surface of 1950 MPa, density 98,5 ±0,14. g/cm³. Ceramics were grinded and faceted, according to ISO standard 1832, and subjected to turning tests in a ROMI lathe brand, model GL240M, using cutting speeds of 500, 800 and 1000 m/min with different feed rates. The machining results showed low occurrence of flank wear to all cutting speeds, and better surface finishing average values of Ra = 0,4935 μm and Rt = 8,112 μm. In general, it could be seen that the tool presents important potential to machining 6005 alloy, and that the use of correct parameters can decrease and/or eliminate subsequent processes, providing important reductions in costs related to the machining processes