Effect finishing and polishing procedures on the surface roughness of IPS Empress 2 ceramic

Objective. To evaluate the surface roughness of IPS Empress 2 ceramic when treated with different finishing/polishing protocols. Materials and methods. Sixteen specimens of IPS Empress 2 ceramic were made from wax patterns obtained using a stainless steel split mold. The specimens were glazed (Stage 0-S0, control) and divided into two groups. The specimens in Group 1 (G1) were finished/polished with a KG Sorensen diamond point (S1), followed by KG Sorensen siliconized points (S2) and final polishing with diamond polish paste (S3). In Group 2 (G2), the specimens were finished/polished using a Shofu diamond point (S1), as well as Shofu siliconized points (S2) and final polishing was performed using Porcelize paste (S3). After glazing (S0) and following each polishing procedure (S1, S2 or S3), the surface roughness was measured using TALYSURF Series 2. The average surface roughness results were analyzed using ANOVA followed by Tukey post-hoc tests (α = 0.01) Results. All of the polishing procedures yielded higher surface roughness values when compared to the control group (S0). S3 yielded lower surface roughness values when compared to S1 and S2. Conclusions. The proposed treatments negatively affected the surface roughness of the glazed IPS Empress 2 ceramic. © 2013 Informa Healthcare.

Effect of fiber surface on flexural strength in carbon fabric reinforced epoxy composites

The effect of carbon fiber surface characteristics on flexural properties of structural composites is studied in this work. Two types of intermediate modulus carbon fibers were used: T800HB and IM7. Results revealed that higher mechanical properties are linked with higher interfacial adhesion. Morphologies and chemical compositions of commercial carbon fibers (CF) were characterized by Fourier Transformed Infra Red (FTIR) and Scanning Electronic Microscopy (SEM). Comparing the results, the T800HB apparently has more roughness, since the IM7 seems to be recovered for a polymeric film. On other hand, the IM7 one shows higher interactivity with epoxy resin system Cycom 890 RTM. Composites produced with Resin Transfer Molding (RTM) were tested on a flexural trial. Interfacial adhesion difference was showed with SEM and Dynamic Mechanical Analyses (DMA), justifying the higher flexural behavior of composites made with IM7 fibers. © 2013 Elsevier B.V. All rights reserved.

Surface Roughness of Acrylic and Silicone-Based Soft Liners: In Vivo Study in a Rat Model

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Leaf anatomical traits are correlated with tree dominance in a Neotropical deciduous forest

Deciduous forests from the neotropics are one of the most endangered forest types in the world due to the exploitation of their natural resources by mankind. Many aspects of these ecosystems have been studied; however, there is a lack of information about leaf structure and the effects of tree dominance on their structural leaf patterns. In this article, we examine leaf anatomy and specific leaf areas (SLA) in 13 tree species differing in their dominance in a Dry Forest site in Central Brazil, relating leaf anatomical traits with phytosociological aspects. Leaf anatomical traits differed according to tree dominance: greater leaf thickness (achieved through greater thickness of the mesophyll), low values of SLA and bigger stomata were found for the most dominant species, whereas the less dominant species showed thinner leaves with high SLA, as well as numerous and small stomata. These responses suggest that tree dominance is an important indirect effect associated with vertical light availability in the forest. These strategies are probably related to the accomplishment of a high performance in carbon gain and water economy, given the distinction in irradiance that the leaves of different species are subject to in the dry forest. © 2013 Copyright The Royal Society of New Zealand.

Optical, mechanical and surface properties of amorphous carbonaceous thin films obtained by plasma enhanced chemical vapor deposition and plasma immersion ion implantation and deposition

Diverse amorphous hydrogenated carbon-based films (a-C:H, a-C:H:F, a-C:H:N, a-C:H:Cl and a-C:H:Si:O) were obtained by radiofrequency plasma enhanced chemical vapor deposition (PECVD) and plasma immersion ion implantation and deposition (PIIID). The same precursors were used in the production of each pair of each type of film, such as a-C:H, using both PECVD and PIIID. Optical properties, namely the refractive index, n, absorption coefficient, α, and optical gap, ETauc, of these films were obtained via transmission spectra in the ultraviolet-visible near-infrared range (wavelengths from 300 to 3300 nm). Film hardness, elastic modulus and stiffness were obtained as a function of depth using nano-indentation. Surface energy values were calculated from liquid drop contact angle data. Film roughness and morphology were assessed using atomic force microscopy (AFM). The PIIID films were usually thinner and possessed higher refractive indices than the PECVD films. Determined refractive indices are consistent with literature values for similar types of films. Values of ETauc were increased in the PIIID films compared to the PECVD films. An exception was the a-C:H:Si:O films, for which that obtained by PIIID was thicker and exhibited a decreased ETauc. The mechanical properties - hardness, elastic modulus and stiffness - of films produced by PECVD and PIIID generally present small differences. An interesting effect is the increase in the hardness of a-C:H:Cl films from 1.0 to 3.0 GPa when ion implantation is employed. Surface energy correlates well with surface roughness. The implanted films are usually smoother than those obtained by PECVD. ©2013 Elsevier B.V. All rights reserved.

Decreasing pH of mammary gland secretions is associated with parturition and is correlated with electrolyte concentrations in prefoaling mares

The objectives of this study were to determine pH of the mammary gland secretions and the corresponding electrolyte concentrations in prefoaling mares. Pregnant mares (seven primiparous and seven multiparous) were monitored daily from 310.320 days of gestation until parturition. Prefoaling mammary gland secretions were collected, and pH was immediately determined with a pH meter and pH strip test. An aliquot of prefoaling mammary secretions was frozen and stored until further analyses. After parturition, samples from day .4 to 0 (day of foaling) were thawed and electrolyte concentrations (ie, Ca2+, Mg2+, Na+, K+ and Cl-) were determined with an automated analyser. Data were analysed via a mixed model with the mare as a random effect. Correlations were determined between pH and electrolyte concentrations by the Pearson product-moment for each pair. There was significant reduction in pH of mammary secretions on the day of foaling (P<0.0001), and most mares (11/14) with a pH .7 foaled within 24 hours. There was high correlation between the two pH methods (r=0.93). Additionally, there were significant (P<0.05) increases in Ca2+ and K+ concentrations, and significant decreases in Na+ and Cl- concentrations from one day before to the day of foaling. The pH of mammary secretions was highly and significantly (P<0.001) correlated with Na + (r=0.87), Cl- (r=0.85), Ca2+ (r=-0.88); and K+(r=.0.80) concentrations, and moderately correlated with Mg 2+ (r=-0.58). Daily evening pH measure of the mammary gland secretions can predict foaling in most mares.

Energia específica de corte e integridade superficial no microfresamento do ABNT 1045

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Redes neurais: aplicação no monitoramento da vida de ferramentas de corte

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial distribution of Yellow Sigatoka Leaf Spot correlated with soil fertility and plant nutrition

This study analyzed the spatial distribution of Yellow Sigatoka Leaf Spot relative to soil fertility and plant nutritional status using geostatistics. The experimental area comprised 1.2 ha, where 27 points were georeferenced and spaced on a regular grid 18 × 18 m. The severity of Yellow Sigatoka, soil fertility and plant nutritional status were evaluated at each point. The spherical model was adjusted for all variables using restricted maximum likelihood. Kriging maps showed the highest infection rate of Sigatoka occurred in high areas of the field which had the highest concentration of sand, while the lowest disease was found in lower areas with lower silt, organic matter, total exchangeable bases, effective cation exchange capacity, base saturation, Ca and Mg in soil, and foliar sulfur (S). These results may help farmers manage Yellow Sigatoka disease more effectively, with balanced fertilization and reduced fungicide application. This practice minimizes the environmental impact and cost of production while contributing to production sustainability.

Efeitos de diferentes concentrações de dextrose e lipopolissacarídeo no comportamento corrosivo da liga Ti-6Al-4V com superfície usinada e tratada com duplo ataque ácido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ab Initio correlated all electron Dirac-Fock calculations for eka-francium fluoride (E119F)

Resultados obtidos por cálculos Dirac-Fock correlacionados de 4 componentes para o fluoreto do elemento E119 (Eka-Frâncio) com base estável e precisa, livre de prolapso variacional, são reportados neste trabalho. No nível CCSD(T), a distância de equilíbrio R_e, frequência harmônica ω_e e energia de dissociação D_e são 2,432 Å, 354,97 cm_-1 e 116,92 kcal mol_-1, respectivamente. Também são reportados base livre de prolapso variacional de 4 componentes para o elemento 119, uma curva analítica de energia potencial precisa e o espectro vibracional a partir dos dados obtidos no nível CCSD(T). Nossos resultados sugerem que a molécula E119F deva ser menos iônica que seus fluoretos alcalinos homólogos mais leves, em contraste com o senso químico comum baseado nas propriedades periódicas - era de se esperar nesta molécula a ligação química mais iônica possível. Também encontramos que a correção do tipo modelo de carga para negligenciar as integrais do tipo SS resulta em erros insignificantes e acelera os cálculos cerca de 3 vezes no nível CCSD(T) e cerca de 4 vezes no nível DFT/B3LYP.

Etidronate from Medicine to Endodontics: effects of different irrigation regimes on root dentin roughness.

An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics.

Sugarcane productivity correlated with physical-chemical attributes to create soil management zone

The socioeconomic importance of sugar cane in Brazil is unquestionable because it is the raw material for the production of ethanol and sugar. The accurate spatial intervention in the management of the crop, resulting zones of soil management, increases productivity as well as its agricultural yields. The spatial and Person's correlations between sugarcane attributes and physico-chemical attributes of a Typic Tropustalf were studied in the growing season of 2009, in Suzanápolis, State of São Paulo, Brazil (20°28'10'' S lat.; 50°49'20'' W long.), in order to obtain the one that best correlates with agricultural productivity. Thus, the geostatistical grid with 120 sampling points was installed to soil and data collection in a plot of 14.6 ha with second crop sugarcane. Due to their substantial and excellent linear and spatial correlations with the productivity of the sugarcane, the population of plants and the organic matter content of the soil, by evidencing substantial correlations, linear and spatial, with the productivity of sugarcane, were indicators of management zones strongly attached to such productivity.

Quality of life profile and correlated factors in chronic leg ulcer patients in the mid-west of São Paulo State, Brazil

BACKGROUND: Chronic leg ulcer may have an impact on patients' quality of life.OBJECTIVES:This study aimed to identify the impact of leg ulcers on patient's quality of life using the Dermatology Life Quality Index and to define the main factors correlated with this perception.METHOD:Cross-sectional, non-probabilistic sampling study. We included patients with chronic leg ulcers being treated for at least 3 months. A sociodemographic and clinical survey was conducted to assess the profile of the ulcers. We administered a screening for depressive symptoms and the Dermatology Life Quality Index. We performed a descriptive statistical analysis, chi-square test and Mann-Whitney test for categorical data, Pearson for numeric variables, and multiple regression for categorical data.RESULTS:Forty-one patients were assessed. Their mean age was 61.78 years. Venous ulcers (48.8%) were the most prevalent. Seventy-three percent of the sample perceived no impact/low impact on quality of life in the past week, and 26.8% perceived moderate/high impact. A multiple regression analysis identified the causes of lesion, pain related to the ulcers, time of onset, and severity of the depressive symptoms as the variables that had an influence on quality of life.CONCLUSIONS:The majority of the sample perceived low or no impact of the condition on the quality of the life. The variables etiology of the lesion (p<0.001), pain related to the ulcers (p=0.001), time of onset (p=0.006), and severity of the depressive symptoms (p<0.001) had an influence on the quality of life, suggesting the need for further studies with more robust designs to confirm the causal relationship between these characteristics and quality of life.

Desenvolvimento de sistemas multifuncionais baseados em híbridos orgânico-inorgânicos dopados

Pós-graduação em Química - IQ