Estudo do uso de ferramentas cerâmicas na usinagem de inconel 718

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da usinagem do INCONEL 718

The nickel superalloys are known as being a material with poor machinability, they have some properties like high hardness, good resistance at high temperature, tendency to weld with the tool material at high temperature, etc. In the aerospace, biomedical and petrochemical industry, are increasing the need to use materials that resist to aggressive process and environment. In these uses, it has increased the use of nickel-based superalloys like Inconel 718 and consequently the need to research new techniques and tools to improve the machinability of this material. For the superalloys and resistant alloys at high temperatures is considered that the difficulty in the machining regards to the combination of the relatively high cutting forces and high temperatures that grow during the machine process, causing deformation or breakage of the cutting tool. This work purpose is to develop the study of the machining of external cylindrical turning of the nickel based alloy Inconel 718, using ceramic tools, seeking the optimization of machining this alloy, looking to provide real productive increases without the need of investments in new production means. The machining test were accomplished using commercials hard metal tools and the results were compared each other to find the best tool and the best parameter. The conclusion is that the tool TNMG160408-23 -class 1005- was the better one, when used with the parameter 60_15_08

Usinagem da liga de níquel inconel 718 com pastilhas de cerâmica

The machining of super alloys resistant to high temperatures such as nickel alloys, inconel 718 specifically, is a very difficult job to obtain improvements in the process, due to the difficulty of machining at high cutting speeds, the use of these alloys in industries showed great developments in recent years, its application in aeronautical industry spread being used in vane turbo, compressor parts, props and set elements. The automotive, chemical, medical and others also took advantage of the great features of inconel 718 and has used the material. The high temperature resistant alloys have high machining difficulty, a fact that is associated with high cutting forces generated during machining which result in high temperatures. High levels of temperatures can cause deterioration of the cutting edge, with subsequent deformation or breakage, wear most common obtained in machining such materials are flank wear the formation of built-up edge for cutting and notch wear. The experimental part of the work consists in machining of nickel-based alloy Inconel 718 heat treated for hardness, using a tool based ceramic silicon nitride Sandvik (Si3N4) in order to compare the best results obtained in the master's thesis of SANTOS (2010) who used a tool ceramics also the basis of silicon nitride which was developed in the doctoral thesis of SOUZA (2005). Assays were performed on a CNC lathe and was noted for each cutting edge results obtained. Tests were made starting from an initial condition of the tool with cutting speed of 200 m/min, feed 0.5 mm and 0.5 mm depth of cut was reduced cutting speed for the subsequent tests with the same conditions of feed and depth of cut. The tool presented wear instant under two 200 m/min and 100 m/min, premature rupture of 50 m/min and finally cut provided with difficulty... (Complete abstract click electronic access below)

Activity of sesame leaf extracts to the leaf-cutting ant Atta sexdens rubropilosa (Hymenoptera : Formicidae)

Crude extracts of new and old sesame leaves (Sesamum indicum, Linaeus) obtained by a sequential process of extraction were tested through contact experiments to investigate their toxicity to Atta sexdens rubropilosa (Forel) workers. Methanol extract of old leaves was toxic to leaf-cutting ants at the lower tested concentration (20mg.ml(-1)). This extract was fractioned and their fractions were tested showing a toxic effect of the methanol fraction. The methanol fraction was fractioned again and the sub fraction responsible for worker's toxicity is composed of some sugars.

Pendimethalin aplicado à casca de arroz e serragem para o controle de plantas daninhas em Ixora chinensis Lam.

A aplicação de herbicidas residuais à coberturas mortas pode aumentar a eficiência desses materiais no manejo da comunidade infestante. Objetivou-se, com este trabalho, avaliar a possibilidade de aplicação do pendimethalin à casca de arroz e à serragem para o controle de plantas daninhas em Ixora chinensis. Dois experimentos foram conduzidos aplicando-se o pendimethalin às coberturas mortas através de embebição e pulverização do herbicida, variando-se também a quantidade de cobertura utilizada. As espécies de plantas daninhas que ocorreram com maior frequência foram Alternanthera tenella, Blainvillea rhomboidea, Cenchrus echinatus e Commelina benghalensis. Há possibilidade de aplicação do herbicida pendimethalin à palha de arroz ou à serragem para controle de plantas daninhas em I. chinensis, principalmente quando ocorrem chuvas regulares e bem distribuídas. Há evidências de que a embebição da cobertura morta no herbicida seja um pouco mais eficiente no controle das plantas daninhas que a sua pulverização sobre a cobertura. Possivelmente, a quantidade de cobertura morta utilizada influencia na eficiência de controle, apesar deste fato não ter ficado claro neste trabalho.

Emergência de sida rhombifolia l. em diferentes épocas e profundidades de semeadura

The major problems in pasture areas are weed management. Sida rhombifolia L. is a major weed of these areas, causing serious problems for the farmers. This research aimed to understand the importance of Sida rhombifolia L. seed depth in the soil profile to increase the germination rate and seedling emergence potential. During the month of September 2008 (spring) and January 2009 (summer), two assays were carried out under greenhouse conditions and the seeds were sown at 0, 1, 2, 3, 4, and 5 cm from the soil surface. The experiment was conducted in pots, 5 L, with 5 replicates containing 50 seeds per pot. In both seasons, the emergence percentage and germination speed were increasing until the 17th day after sowing, and the depths of one, two and three centimeters were those which obtained higher emergencies and germination speed. In one cm depth, the germination was 28% and 32% in spring and summer, respectively, statistically different from the other depths. however, five depths centimeters; the germination was only 8% and 13% respectively.

Reação de laranjeiras-doces quanto à resistência a Guignardia citricarpa

O objetivo deste trabalho foi determinar o comportamento de variedades de laranjas-doces quanto à resistência a Guignardia citricarpa, agente causal da mancha preta dos citros (MPC). Os ensaios foram conduzidos em dois campos, nos municípios de Rincão e Tambaú, SP. As mudas foram formadas em viveiro localizado na Estação Experimental de Citricultura de Bebedouro-SP. Para tal, foram utilizadas borbulhas de plantas cítricas existentes no Banco Ativo de Germoplasma de Citros da Estação Experimental de Citricultura de Bebedouro (EECB), Bebedouro-SP. Avaliou-se a severidade da doença por meio de escala de notas, de zero (ausência de sintomas) a seis (sintomas severos). A partir de tais dados, foi calculado o valor do índice de doença (ID). em 2007, no experimento de Rincão, dentre as 65 variedades avaliadas, apenas 59 produziram frutos, sendo constatada ausência de sintomas da doença em Castellana, Maçã e Olivelands. Nas demais variedades, os níveis de severidade variaram de 0,35 para Grada a 3,0 para China SRA-547. Para Tambaú, os valores de severidade variaram de 0,40 para a variedade Cadenera a 2,46 para Pera. No ano de 2008, em Rincão, todas as variedades mostraram-se suscetíveis. Os níveis de severidade verificados variaram de 0,18 para a variedade Belladona, e 3,92 para Vera 97. em Tambaú, somente a variedade Navelina não apresentou sintomas da MPC. Foi observado que, dentre as plantas que frutificaram, e com exceção daquelas cujos frutos mostraram-se assintomáticos, os valores de severidade variaram de 0,11 para a variedade Tua Mamede a 3,57 para Amares.

Incontinência urinária após gonadectomia em fêmeas caninas

A incontinência urinária adquirida é uma condição debilitante e, muitas vezes, incurável que acomete fêmeas castradas e raramente fêmeas inteiras ou machos. A manifestação clínica pode ocorrer em qualquer momento após a gonadectomia e resulta em graves problemas no manejo do paciente. Os mecanismos que desencadeiam a incontinência após ovariectomia envolvem decréscimo na pressão de fechamento uretral, alterações hormonais, aumento na deposição de colágeno na musculatura lisa da bexiga, diminuição na contratilidade do músculo detrusor e redução na resposta aos estímulos elétricos e ao carbachol. O diagnóstico é realizado pelo histórico do animal, pelo exame físico, pelos exames laboratoriais, pelo perfil de pressão uretral, pela ultrassonografia e pelas radiografias abdominais. O tratamento clínico envolve utilização de fármacos -adrenérgicos, estrógenos, análogos de GnRH e agentes antidepressivos. As técnicas cirúrgicas recomendadas correspondem à uretropexia, cistouretropexia, aplicação de colágeno na uretra e colpossuspensão. Melhor compreensão da etiologia, da fisiopatologia, dos métodos de diagnóstico e tratamentos é fundamental em razão do pouco conhecimento e da identificação dessa condição no Brasil.

Effect of inclusion of citrus pulp in the diet of finishing swines

No primeiro ensaio foram utilizados 16 suínos machos castrados da linhagem Topigs, com peso inicial de 80,5±4,7 kg, para a avaliação biológica da polpa cítrica. Por apresentar 18,85% de fibra em detergente neutro e 41,18% de fibra solúvel em detergente neutro, a polpa cítrica mostrou-se como um ingrediente viável a ser utilizado em programas de restrição alimentar qualitativa. No segundo ensaio foram utilizados 36 suínos machos castrados, com peso inicial de 83,7±5,1 kg, recebendo rações com níveis de 0, 10, 20 e 30% de polpa cítrica. Os animais foram abatidos com peso próximo de 130 kg, sendo avaliados quanto ao desempenho e parâmetros séricos. Houve resposta quadrática (P<0,05) para ganho diário de peso e número de dias para atingir o peso de 130 kg, em função dos níveis de polpa cítrica na dieta, sendo observados melhores resultados com níveis de inclusão de 10,79 e 10,97%, respectivamente. Para os parâmetros séricos avaliados, não foi observado efeito (P>0,05) dos níveis de polpa cítrica sobre a uréia e triacilgliceróis, porém houve resposta quadrática (P<0,05) para o colesterol em função dos níveis de polpa cítrica.

Chemical composition and fermentation characteristics of elephant grass silage with biodiesel industry co-products

The objective of this research was to evaluate the effect of three concentrations (3, 6, and 9%) of forage turnip (Raphanus sativus) and physic nut (Jatropha curcas) cakes on dry matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, lignin, acid detergent insoluble nitrogen neutral detergent insoluble nitrogen contents, in vitro dry matter digestibility, pH values and concentrations of N-NH3 in elephant grass silages. It was used an entirely randomized design in factorial arrangement [(2x3)+1]. Experimental PVC silos were used and ensiled material was kept for 62 days. The addition of cakes increased the dry matter contents (P<0.05). The fibrous fractions were reduced (P<0.05) with the inclusion of cakes during the grass ensilage and the CP contents increased (P<0.05). The forage turnip cake provided the same pH and N-NH3 values in ideal levels and the physic nut, added to 9%, increased those values (P<0.05). IVDMD was reduced (P<0.05) when the cakes were added. These co-products can be used in small amounts for elephant grass ensilage in order to provide improvement in chemical and fermentation characteristics of the silages. Nevertheless, physic nut cake shows limitations for its use in animal feeding due to the presence of toxic compounds, making necessary studies for their identification and elimination.

Changes on emitter discharge under different water temperature and pressure

The study was conducted at the Research Laboratory of Hydraulic and Irrigation Group in the Rural Engineering Department, Technical University of Madrid (Universidad Politecnica de Madrid), Madrid, Spain. Water temperatures of 20, 30, 40 degrees C and system pressures often encountered in irrigation practices of 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 and 200 k Pa were applied to determine the effects of different water temperatures and pressures on emitter discharge. Non-pressure compensating in-line emitter which has turbulent flow regime with a long-path (labyrinth), emitter discharge was 4 L h(-1) at system pressure of 100 kPa according to the manufacturer recommended, was used. Emitters were spaced 20 cm along the drip laterals with 16 mm diameter. Discharge equations and coefficients of variation related to temperatures of 20, 30 and 40 degrees C were obtained as q = 0.375H(0.51), q = 0.358H(0.52), q = 0.346H(0.53) and 2.68, 2.09, 3.65, respectively. Discharge of the emitter was affected by different system pressures and increased as potentially (R = 0993-0996). In general. the emitter discharge increased with increasing temperature. However, especially in the common system pressures of 90-120 k Pa, differences of obtained emitter discharges between the different water temperatures were not significant (1%).

Reguladores vegetais e atividade de invertases em cana-de-açúcar em meio de safra

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

Eficácia do glyphosate e 2,4-d no controle de espécies de trapoerabas (commelina spp.)

The aim of this study was to evaluate the efficacy of glyphosate and 2,4-D for the Commelina benghalensis, Commelina diffusa and Commelina erecta. Three experiments were conducted in a greenhouse in a completely randomized in factorial scheme 3x7+1 (three herbicides x seven periods - hour after application) for two methods for measuring absorption of herbicides (simulated rain and cut the leaves applied), and a control without application, with four replications. The herbicides used were: glyphosate (1,080 g ha(-1)), 2,4-D amine (720 g ha(-1)) and, mixture glyphosate + 2,4-D (720 + 720 g ha(-1)). It was evaluated seven time intervals for washing (simulating rainfall after application) and cut (simulation abortion as a strategy of defense) the leaves applied: 0, 2, 4, 6, 8, 12 and 24 hours after herbicide application (HHA). The minimum period for absorption of glyphosate alone and in mixture with 2,4 -D presented a satisfactory control (> 90.0%) was around 12 HHA to C. benghalensis, C. diffusa and C. erecta, independently of washing or cut the leaves applied. This observed behavior can influence the time required without rain after herbicide application, besides that, the plants aborted part of the stem with injuries to avoid the herbicide translocation, especially when was used the 2,4-D alone. Concluded that glyphosate alone and in mixture with 2,4-D were efficient and that the differences in the control of species may be due to variation of time to absorb the herbicide.

Adhesion of Histoplasma capsulatum to pneumocytes and biofilm formation on an abiotic surface

The pathogenic fungus, Histoplasma capsulatum, causes the respiratory and systemic disease 'histoplasmosis'. This disease is primarily acquired via inhalation of aerosolized microconidia or hyphal fragments of H. capsulatum. Evolution of this respiratory disease depends on the ability of H. capsulatum yeasts to survive and replicate within alveolar macrophages. It is known that adhesion to host cells is the first step in colonization and biofilm formation. Some microorganisms become attached to biological and non-biological surfaces due to the formation of biofilms. Based on the importance of biofilms and their persistence on host tissues and cell surfaces, the present study was designed to investigate biofilm formation by H. capsulatum yeasts, as well as their ability to adhere to pneumocyte cells. H. capsulatum biofilm assays were performed in vitro using two different clinical strains of the fungus and biofilms were characterized using scanning electron microscopy. The biofilms were measured using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium-hydroxide (XTT) reduction assay. The results showed that both the H. capsulatum strains tested were very efficient at adhering to host cells and forming biofilm. Therefore, this is a possible survival strategy adopted by this fungus.

Heteroplasmy in Hair: Study of Mitochondrial DNA Third Hypervariable Region in Hair and Blood Samples

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