Análise da lubricidade do biodiesel brasileiro de ésteres etílicos de soja e girassol

Fuel is a material used to produce heat or power by burning, and lubricity is the capacity for reducing friction. The aim of this work is evaluate the lubricity of eight fossil and renewable fuels used in Diesel engines, by means of a HFRR tester, following the ASTM D 6079-04 Standard. In this conception, a sphere of AISI 52100 steel (diameter of 6,000,05 mm, Ra 0,050,005 μm, E = 210 GPa, HRC 624, HV0,2 63147) is submitted to a reciprocating motion under a normal load of 2 N and 50 Hz frequency to promote a wear track length of 1.10.1mm in a plan disc of AISI 52100 steel (HV0,05 18410, Ra 0,020,005 μm). The testing extent time was 75 minutes, 225,000 cycles. Each one test was repeated six times to furnish the results, by means of intrinsic signatures from the signals of the lubricant film percentage, friction coefficient, contact heating, Sound Pressure Level, SPL [dB]. These signal signatures were obtained by two thermocouples and a portable decibelmeter coupled to a data acquisition system and to the HFRR system. The wettability of droplet of the diesel fuel in thermal equilibrium on a horizontal surface of a virgin plan disc of 52100 steel, Ra 0,02  0,005 μm, were measured by its contact angle of 7,0  3,5o, while the results obtained for the biodiesel B5, B20 and B100 blends originated by the ethylic transesterification of soybean oil were, respectively, 7,5  3,5o, 13,5  3,5o e 19,0  1,0o; for the distilled water, 78,0  6,0o; the biodiesel B5, B20 and B100 blends originated by the ethylic transesterification of sunflower oil were, respectively, 7,0  4,0o, 8,5  4,5o e 19,5  2,5o. Different thickness of lubricant film were formed and measured by their percentage by means of the contact resistance technique, suggesting several regimes, since the boundary until the hydrodynamic lubrication. All oils analyzed in this study promoted the ball wear scars with diameters smaller than 400 μm. The lowest values were observed in the scar balls lubricated by mixtures B100, B20 and B5 of sunflower and B20 and B5 of soybean oils (WSD < 215 μm)

Montagem e operação de um secador pneumático tipo flash

In this work, a pneumatic dryer has been designed and assembled in laboratory scale in order to study and evaluate configurations more efficient for application in drying of important materials of Northeast region in Brazil. The equipment was tested with drying of corn and rice grains, in conditions of temperature and air velocity at 80 oC and 35 m/s, respectively. For this type of dryer, it is recommended to work at temperatures above 200 °C and air velocity with higher dynamic pressure. However, even under operating conditions below what it is recommended, the results obtained with the pneumatic dryer were satisfactory. In addition, experiments of drying were performed by using a cabinet dryer (batch dryer) under the same conditions used in the pneumatic dryer. Flash one curves for the corn were fitted satisfactorily by applying of the Lewis model, while a better agreement was found for rice by using the Page model. The data obtained with both drying processes allowed to compare the performance between pneumatic and batch dryers. In respect to drying rate, the pneumatic dryer presented a similar performance to the batch dryer during processing with corn and a superior performance to the last one during processing with rice. Therefore, it was possible to verify that the pneumatic dryer assembled in this preliminar study can be applied for different materials and under different operating conditions

Estimativas das componentes da radiação solar incidente em superfícies inclinadas baseadas na radiação global horizontal

Statistics equations and validations with groups of annual and monthly data were evaluated for global, direct and diffuse solar radiation components incident on the tilted surface to 12.85, 22.85 and 32.85 degrees with the face North, in climate and geographical conditions of Botucatu, SP. It was employed the fractions of three components of extraterrestrial radiation in correlation with the coefficient clearness index horizontal plane, in a database of April/1998 to December/2007, whose measures at different periods in three inclinations, however concomitant to the horizontal plane. Increasing the angle of the surface led to increased scattering of the daily values of clearness index for inclined and horizontal surfaces. In annual groups, the lower performances were observed in the estimation of inclined daily diffuse radiation, with maximum Root Mean Square Error to 3.89 MJ m(-2) d(-1) (43.65%) and adjustments around 62%. In estimates of global and direct components of solar radiation on inclined planes, both annual and monthly equations can be applied, with performance dependents to climatic conditions.

Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus)

Methyl mercury (MeHg) is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group) or by trophic exposure (T group). Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas), 0.05 (N = 2 retinas) and 0.1 mg/kg (N = 1 retina), whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina), 0.075 (N = 8 retinas) or 0.0075 (N = 4 retinas) mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

Avaliação do desgaste abrasivo causado pelas cerâmicas Duceram e Vita em resinas compostas pelo método do disco retificado

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

Comparação dos valores de desgaste abrasivo e de microdureza de 13 resinas compostas usadas em odontologia através do método do disco retificado

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

Aspectos anatômicos do olho e neuroquímicos da retina do mocó (Kerodon rupestris)

The visual system is an important link between the animal and the environment, com profound influences on the habits and lifestyle in various habitats. Adaptive mechanismsto the temporal niche are present in the visual system of many vertebrates, involving changins in ocular dimensios and design, retinal cell distribution and organization of neurochemical circuits related to the retinal resolution or sensitivity. The sensory system of the eye is represented by the retina, whose organization is responsible by receipty, initial analysis, and transmission of the information to the brain. The knowledge of the position of the eyes in the head and the distribution of retinal cells allow to identify adaptive aspects of each species to its visual field, which is characteristic to the ecological niche it occupies. In this research, we study eye anatomical characteristics and retina neurochemical features of the rock cavy (Kerodon rupestris), a tipical Brazilian rodent from the suborder Hystricomorpha, family Caviidae. The rock cavy has lateral eyes well constitute bony orbit and well differentiated extrinsic muscle. The study of the descriptive and morphometric anatomy of the showed mean values of axial diameter 10.7±0,5mm and equatorial diameter 11.6±0.7mm. The pupil is slit shaped and the lens has mean axial diameter 5.4±0.03 mm, corresponding to ~45% of the axial diameter of the eye. The posterior nodal distance and the retinal magnification factor were estimated at 6.74 mm e 118 μm/grau, respectively. Flat mounts were processed for Nissl stain, and the topographic distribution of ganglion cells showed a moderate visual band, just below the optic disc, with higher density in the ventral retina. Retinal vertical sections and flat mounts were processed for immunohistochemistry to visualize tyrosine hydroxilase (TH) and thus two types of TH+ cells were detected. Type 1 cells had strong TH-immunoreactivity, the body cell varied from 120.047 to 269.373 μm2 stratifying in the sublamina 1 of the IPL. Type 2 cells were weakly TH-imunoreactive, had cell body located mostly in the IPL, varying from 54.848 to 177.142 μm2, constituting ~10% of the TH+ cells. Both cell types exhibited similar topographic distribution with higher density found in a horizontal band along of the naso-temporal axis in the dorsal retina. The total population of dopaminergic cells was 2,156±469,4 cells, occupying an average area of 198,164 μm2. The presence of cones and rods was detected by immunohistochemistry in vertical sections and flat mounts. S cones density is around 10 times smaller than L cones, with different degree of spatial organization. Other retinal neuronal populations of the rock cavy were also detected in vertical sections with specific markers. Comparative analysis of the anatomical characteristics of the rock cavy eye 12 suggest that it was designed to acquire higher sensitivity to light, at expense of image sharpness, compatible with a vision at mesopic conditions. Additionally, the distribution of the 2 subtypes of dopaminergic cells in a naso-temporal band in the dorsal retina seems suitable to a gain in sensitivity, coherent with an animal with predominantly crepuscular activity pattern

Integrated treatment to resolve a horizontal root fracture

Root fractures are defined as those that involve cement, dentin and pulp, comprising from 0.5 to 7% of injuries in permanent dentition. Diagnosis is made through clinical and radiographic exams, the latter frequently being limited by the position of the fracture. Treatment varies according to the displacement and vitality of the fragments. The authors present a clinical case of recurrent trauma of tooth 21 causing a horizontal root fracture in the middle third. After several attempts at endodontic treatment, the option was to remove the apical fragment by surgery. The postoperative period of 4 years shows very satisfactory results with regard to wound repair and tooth mobility, or implantation of the coronal segment.

Horizontal transfers of Mariner transposons between mammals and insects

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

Horizontal and vertical tree community structure in a lowland atlantic rain forest, southeastern Brazil

A estrutura horizontal e vertical do componente arbóreo foi investigada em um trecho de Floresta Atlântica baixo-montana através de um levantamento fitossociológico em dois blocos amostrais de 0,99 ha cada no Parque Estadual Intervales. Todos os indivíduos com DAP > 5 cm foram registrados. Foram amostrados 3.078 indivíduos distribuídos em 172 espécies. O índice de diversidade de Shannon foi de H' = 3,85 nat.ind.-1. A família Myrtaceae se destacou tanto em número de espécies (38) quanto em número de indivíduos (745) no levantamento. Euterpe edulis Mart. teve o maior valor de importância (33,98%), abrangendo 21,8% do total de indivíduos registrados. O índice de similaridade quantitativo foi maior do que o qualitativo, mostrando pouca variação estrutural entre os blocos amostrais, mas a grande quantidade de espécies pouco abundantes, resultou em pronunciadas diferenças florísticas entre eles. Uma análise de correspondência retificada (DCA) gerou três estratos verticais arbitrários. O estrato A (> 26 m) teve a menor densidade e foi bem representado pelas espécies Sloanea guianensis (Aubl.) Benth. e Virola bicuhyba (Schott. ex A.DC.) Warb. O estrato B (8 m < h < 26 m) mostrou a maior riqueza e diversidade florística, e o estrato C (< 8 m) a maior densidade. Euterpe edulis, Guapira opposita (Vell.) Reitz, Garcinia gardneriana (Planch. & Triana) Zappi e Eugenia mosenii (Kausel) Sobral foram bem representadas nos estratos B e C da floresta. A existência de estratos verticais em florestas tropicais é discutida, recomendando-se o uso da DCA para estudos da estratificação vertical em outras florestas tropicais.

Automatic Classification of Three-Phase Flow Patterns of Heavy Oil in a Horizontal Pipe Using Support Vector Machines

The pipe flow of a viscous-oil-gas-water mixture such as that involved in heavy oil production is a rather complex thereto-fluid dynamical problem. Considering the complexity of three-phase flow, it is of fundamental importance the introduction of a flow pattern classification tool to obtain useful information about the flow structure. Flow patterns are important because they indicate the degree of mixing during flow and the spatial distribution of phases. In particular, the pressure drop and temperature evolution along the pipe is highly dependent on the spatial configuration of the phases. In this work we investigate the three-phase water-assisted flow patterns, i.e. those configurations where water is injected in order to reduce friction caused by the viscous oil. Phase flow rates and pressure drop data from previous laboratory experiments in a horizontal pipe are used for flow pattern identification by means of the 'support vector machine' technique (SVM).

Estimativa da irradiação total sobre uma superfície inclinada a partir da irradiação global na horizontal

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

Emprego de nebulizador pneumático de ICP-MS como câmara de diluição em sistemas de injeção em fluxo para determinações multielementares

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Itaipu reservoir limnology: eutrophication degree and the horizontal distribution of its limnological variables

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