Estudo da adesão de pinos endodônticos modificados superficialmente por plasma de oxigênio

The work presents the effect of plasma treatment when applied in fibers or carbon/glass posts in the adhesion fiber/resin and posts/cement. This has for objective the modification of the surface of the fibers, as well as the wettability of the posts, seeking the improvement of the adhesion and of the connection fiber/resin in the processing of polymeric composites reinforced with the same ones. 120 posts (Reforpost) were used and 30 meters of fibers of carbon and of glass (Fibrex), of the company Angelus. The samples were divided in three groups of 40 specimens: GROUP I - 20 posts of glass fiber and 20 of carbon without treatment to it shapes, GROUP II -20 posts of glass fiber and 20 of carbon treated to it shapes in the surface and GROUP III - 20 posts of glass fiber and 20 of carbon make with fibers in natura after plasma treatment. The plasma treatment was accomplished with oxygen and with temperature in the camera fixed at 200°C, for one hour of exhibition. The posts and the fibers were characterized before and after the treatment. The wettability was measure by pendent drop method, and interface fiber/resin and posts/cement were observed by optical and electronic microscopy. It was observed that both wettability and texture were increased with plasma treatment

Mecanismos de desgaste, história térmica e ciclo de vida de componentes de um motor de combustão interna de aeromodelo

We developed an assay methodology that considered the temperature variation and the scanning electron microscopy as a method to quantify and characterize respectively the consumption evolution in three 46 LA machines, with internal combustion and two-stroke engines, 7.64 cm3 cylinder capacity, 23.0 millimeters diameter and 18.4 millimeters course, RPM service from 2.000 to 16.000 rpm, 1.2 HP power, and 272 grams weight. The investigated engines components were: (1) head of the engine (Al-Si alloy), (2) piston (Al-Si alloy) and (3) piston pin (AISI 52100 steel). The assays were carried out on a desktop; engines 1 and 2 were assayed with no load, whereas in two assays of engine 3 we added a fan with wind speed that varied from 8.10 m/s to 11.92 m/s, in order to identify and compare the engine dynamic behavior as related to the engines assayed with no load. The temperatures of the engine s surface and surroundings were measured by two type K thermopairs connected to the assay device and registered in a microcomputer with data recording and parameters control and monitoring software, throughout the assays. The consumed surface of the components was analyzed by scanning electron microscopy (SEM) and microanalysis-EDS. The study was complemented with shape deformation and mass measurement assays. The temperature variation was associated with the oxides morphology and the consumption mechanisms were discussed based on the relation between the thermal mechanical effects and the responses of the materials characterization

Da poesia ao poema: uma leitura do poema-Processo

Caractérisation du "Poema-Processo" au long de sa trajectoire entre les années 1967 et 1972, au regard d´une lecture visant son insertion dans le mouvement d´avant-guarde de la deuxième moitié du XX° siècle, au Brésil. On vérifie la façon dont le mouvement du "Poema-Processo" s´est formé, comme dédoublement de l´art concret, ainsi comme ses adéquations à la conjoncture de son apparition au Brésil, s´établissant une comparaison entre la pratique du poème et les propositions des manifestes lancés. L´analyse des poèmes sélectionnés démontre leur co-relation avec les travaux visuels initiés par les avant-guardes historiques, ainsi comme les réponses de la pratique poétique à la théorie developpée par les principaux représentants, Wlademir Dias-Pinto, Álvaro de Sá et Moacy Cirne. La production poétique et culturelle de Moacy Cirne est abordée en observant sa pratique sur trois points fondamentaux: la production poétique, la critique littéraire donnant de l´emphase à la culture locale et au texte du "Poema-Processo", et la recherche du language des bandes dessinées.

Mel no asfalto: percepções do neutro nos contos de Caio Fernando Abreu

The work of Caio Fernando Abreu has a very vast and impressive thematic horizon , which is usually the core of the papers on the work of this author . This paper proposes to understand this characteristic of a more intricate point of view : perceive and analyze how the work of the author builds itself thematically , but mainly textually . I n other words , as the text enacts his own writing . From this it is noticeable how the text of Abreu plays with some senses through textual constructions that do not impose directly sense to the reader . Thus, the research sees in the chosen corpus , the collection Os dragões não conhecem o paraíso ( 2014 ), the neutral as proposed by the French essayist Roland Barthes (2003 a ). This neutral is understood by Barthes as a possibility to suspend the paradigms that constitute the sense, what exactly justifies the noticeable game in the work of Abreu . This game , to Roland Barthes , is precisely the literature. If the paradigm involves transforming the language , and all language expressions, in a way to propagate ideologies , the literature does not escape this fate . In order to escape this fate , you must fight the language internally ; we must play wit h the language . The neutral is the possibility of the game. Thus , the study sought neutral in Caio Fernando Abreu short stories , presenting it and analyzing it through " figures" which, for Barthes , is a way of perceiving the neut ral through texts , but not in a prescriptive manner. It was proposed , in the analysis , then understand the " Subjectivities ", the " Default ", the " Body " and " Disease " , for example, as possibilities of the game . Finally , in many Abreu’s work instances , the neutral is achieved by textual operations that are not in themselves neutral , but which achieve a " neutral effect ", which explains the game , the literature, in the texts of Caio Fernando Abreu .

Estudo da adesão de pinos endodônticos modificados superficialmente por plasma de oxigênio

The work presents the effect of plasma treatment when applied in fibers or carbon/glass posts in the adhesion fiber/resin and posts/cement. This has for objective the modification of the surface of the fibers, as well as the wettability of the posts, seeking the improvement of the adhesion and of the connection fiber/resin in the processing of polymeric composites reinforced with the same ones. 120 posts (Reforpost) were used and 30 meters of fibers of carbon and of glass (Fibrex), of the company Angelus. The samples were divided in three groups of 40 specimens: GROUP I - 20 posts of glass fiber and 20 of carbon without treatment to it shapes, GROUP II -20 posts of glass fiber and 20 of carbon treated to it shapes in the surface and GROUP III - 20 posts of glass fiber and 20 of carbon make with fibers in natura after plasma treatment. The plasma treatment was accomplished with oxygen and with temperature in the camera fixed at 200°C, for one hour of exhibition. The posts and the fibers were characterized before and after the treatment. The wettability was measure by pendent drop method, and interface fiber/resin and posts/cement were observed by optical and electronic microscopy. It was observed that both wettability and texture were increased with plasma treatment