145 research outputs found

    An approximation to multiple scattering in volumetric illumination towards real-time rendering

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    Many volumetric illumination techniques for volume rendering were developed through out the years. However, there are still many constraints regarding the computation of multiple scattering path tracing in real-time applications due to its natural complexity and scale. Path tracing with multiple scattering support can produce physically correct results but suffers from noise and low convergence rates. This work proposes a new real-time algorithm to approximate multiple scattering, usually only available in offline rendering production, to real-time. Our approach explores the human perceptual system to speed up computation. Given two images, we use a CIE metric stating that the two will be perceived as similar to the human eye if the Euclidean distance between the two images in CIELAB color space is smaller than 2.3. Hence, we use this premise to guide our in vestigations when changing ray and bounce parameters in our renderer. Our results show that we can reduce from 105 to 104 Samples Per Pixel (SPP) with a negligible perceptual difference between both results, allowing us to cut rendering times by 10 whenever we divide SPP by 10. Similarly, we can reduce the number of bounces from 1000 to 100 with a negligible perceptual difference while reducing rendering times by almost half. We also propose a new algorithm in real-time, Lobe Estimator, that approximates these behaviors and parameters while performing twice as faster as the classic Ray Marching technique.Muitas técnicas de ilmuninação volumétrica foram desenvolvidas ao longo dos anos. Entretanto, ainda há muitas restrições na computação de multiple scattering em aplicações de tempo real usando path tracing, devido à sua complexidade e escala. Path tracing com suporte a multiple scattering é capaz de produzir resultados fisicamente corretos, mas sofre de ruídos e baixa taixa de convergência. Portanto, este trabalho propõe um novo algoritmo de tempo real para aproximar multiple scattering, usado em offline rendering. Nossa abordagem irá explorar o sistema perceptual visual humano para acelerar a computação. A partir de duas imagens, nós usamos a métrica da CIE que afirma que duas imagens são percebidas como similar ao olho humano se a distância Euclidiana das duas imagens no espaço de cores CIELAB for menor que 2.3. Dessa forma, nós usamos essa premissa para guiar nossas investigações quando alterando os parâmetros de Samples Per Pixel (SPP) e bounces nos renderizadores. Nossos resultados mostram que podemos redu zir de 105 para 104 Samples Per Pixel (SPP) com uma diferença perceptual negligenciável entre ambos paramêtros, permitindo reduzir o tempo de renderização por 10 a cada vez que dividimos o SPP por 10. Similarmente, nós podemos reduzir o número de bounces de 1000 para 100 com uma diferença perceptual negligenciável, enquanto reduzindo o tempo de renderização por quase metade. Nós também propusemos um novo algoritmo em tempo real, Lobe Estimator, que permite aproximar esses comportamentos e paramê tros enquanto permformando duas vezes mais rápido que o clássico Ray Marching

    Preparation and characterization of polymeric nanoparticles loaded with the flavonoid luteolin, by using factorial design.

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    Nanoparticles containing luteolin flavonoid were prepared by using interfacial polymer deposition following solvent displacement. The formulation was optimized using factorial design. The parameters studied were the type of polymer [poly(ε-caprolactone) and poly(lactic-co-glycolic acid)], nature oil (isodecyl oleate and oleic acid) and the quantity of luteolin. Nanocapsules and nanospheres were also prepared and evaluated. Colloidal suspensions were characterized by evaluating pH, the particle size, the zeta potential, the morphological aspect and the kinetic release. A new High Performance Liquid Chromatography method was developed and validated in order to quantify luteolin in colloidal suspension allowing the analyses of the absolute recovery, entrapment efficiency and the kinetic release. The luteolin-absolute recovery ranged from 61.6% to 95%; entrapment efficiency was nearly 100% in all formulations and the particle sizes were smaller than 185.5 nm. The nanoparticles prepared with isodecyl oleate show a negative zeta potential. On the other hand, when oleic acid was utilized, the zeta potential was positive. The nanoparticles prepared by using isodecyl oleate have a more perfect spherical shape with a regular surface and form, homogeneity, and lower size dispersion. Nanocapsules and nanospheres have a similar release mechanism of pure diffusion according with Korsmeyer-Peppas’s model

    Teaching hospital management during the undergraduate nursing course

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    Learning takes place in the interaction between people through the teaching process, from which the academic community appropriates socially established knowledge. In nursing, teaching education is essential for nursing education, and the role of the teacher in this aspect is fundamental for teaching-learning. Identify the students\u27 expectations in relation to the discipline of hospital management, as well as the gaps found in the methodologies applied in the teaching process. The field research used a questionnaire structured by the researchers. 31 students from the last year of nursing participated in the research. The study was approved by the Research Ethics Committee of Unifunec. The data were analyzed in the Microsoft Office Excel and Microsoft Office Word programs. Of the 31 students interviewed, 55% (17) had a basic notion of how to identify the functions of the nurse manager, 16% (5) could not identify, 16% (5) knew how to identify with some difficulty, 13% (4) easily identified. Regarding the methodologies applied, technological advances were monitored, 51% (16) considered that partially, 39% (12) considered yes, 10% (3) considered no. It was identified that the discipline of hospital management generates many expectations in the students and, at the same time, point out gaps in the construction of this knowledge. Further research is suggested to find alternatives that allow the proximity of reality to learning and in the preparation of nurses to deal with managerial functions

    Preparation and characterization of polymeric nanoparticles loaded with the flavonoid luteolin, by using factorial design

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    Nanoparticles containing luteolin flavonoid were prepared by using interfacial polymer deposition following solvent displacement. The formulation was optimized using factorial design. The parameters studied were the type of polymer [poly(-caprolactone) and poly(lactic-co-glycolic acid)], nature oil (isodecyl oleate and oleic acid) and the quantity of luteolin. Nanocapsules and nanospheres were also prepared and evaluated. Colloidal suspensions were characterized by evaluating pH, the particle size, the zeta potential, the morphological aspect and the kinetic release. A new High Performance Liquid Chromatography method was developed and validated in order to quantify luteolin in colloidal suspension allowing the analyses of the absolute recovery, entrapment efficiency and the kinetic release. The luteolin-absolute recovery ranged from 61.6% to 95%; entrapment efficiency was nearly 100% in all formulations and the particle sizes were smaller than 185.5 nm. The nanoparticles prepared with isodecyl oleate show a negative zeta potential. On the other hand, when oleic acid was utilized, the zeta potential was positive. The nanoparticles prepared by using isodecyl oleate have a more perfect spherical shape with a regular surface and form, homogeneity, and lower size dispersion. Nanocapsules and nanospheres have a similar release mechanism of pure diffusion according with Korsmeyer-Peppas’s model.CNPqCAPESFAPES

    Preparation and characterization of polymeric nanoparticles loaded with the flavonoid luteolin, by using factorial design.

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    Nanoparticles containing luteolin flavonoid were prepared by using interfacial polymer deposition following solvent displacement. The formulation was optimized using factorial design. The parameters studied were the type of polymer [poly(ε-caprolactone) and poly(lactic-co-glycolic acid)], nature oil (isodecyl oleate and oleic acid) and the quantity of luteolin. Nanocapsules and nanospheres were also prepared and evaluated. Colloidal suspensions were characterized by evaluating pH, the particle size, the zeta potential, the morphological aspect and the kinetic release. A new High Performance Liquid Chromatography method was developed and validated in order to quantify luteolin in colloidal suspension allowing the analyses of the absolute recovery, entrapment efficiency and the kinetic release. The luteolin-absolute recovery ranged from 61.6% to 95%; entrapment efficiency was nearly 100% in all formulations and the particle sizes were smaller than 185.5 nm. The nanoparticles prepared with isodecyl oleate show a negative zeta potential. On the other hand, when oleic acid was utilized, the zeta potential was positive. The nanoparticles prepared by using isodecyl oleate have a more perfect spherical shape with a regular surface and form, homogeneity, and lower size dispersion. Nanocapsules and nanospheres have a similar release mechanism of pure diffusion according with Korsmeyer-Peppas’s model

    Autonomy In the Choice of Childbirth in The Primiparous: Understanding Reality

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    Every pregnant woman has the right to care during childbirth and postpartum, and that this is performed in a humane and safe way. To ensure autonomy, it is necessary to put the woman in control of labor and birth, providing the necessary knowledge that allows her to make decisions about her own body. The study aimed to know the autonomy and knowledge of primiparous women in choosing the type of delivery. This is a qualitative field research. The participants were primiparous women, who agreed to participate in the research by signing the Informed Consent Form. The interviews were conducted after approval by the Research Ethics Committee under protocol n. CPEA 31364620.8.0000.5428, opinion n. 4,300,350. In view of the results, the following themes emerged: Reception and neglected bond between health units and pregnant women, revealed by reports of negative and frustrated experiences in the parturition process. Factors that prevent the autonomy of the choice of delivery in pregnant women and negative experiences and frustrated expectations regarding the moment of delivery, in which the reports indicated a lack of explanation of the procedures, lack of communication and prejudiced decision of the physician in relation to the delivery. It was concluded that the study showed the need for actions aimed at women’s health in the pregnancy-puerperal period, which enable conditions for female empowerment in decision-making about the body itself

    Nanopartículas de poli-'épsilon'-caprolactona carregadas com hidrocortisona: preparação usando planejamento fatorial e sua avaliação

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    Polymeric-nanoparticle systems such as nanocapsules and nanospheres have a great potential in applications for nanoencapsulation of corticosteroids which show low solubility in water. The physicochemical characteristics of nanoparticle suspensions are important pre-requisites for the successful development of new dosage form. In this study, hydrocortisone-loaded poly-ε-caprolactone nanoparticles have been prepared by the interfacial deposition method. A 3-factor 2-level factorial design was used to study and optimize nanoparticles formulation. This factorial design was used to study the contrasts and effects of independent variables on particle size distribution, morphology, surface charge, drug content, entrapment efficiency and in vitro drug release profiles. The screened independent variables were: the concentration of hydrocortisone, poly-ε-caprolactone and isodecyl oleate. A High Performance Liquid Chromatography method was developed and validated for hydrocortisone quantification. Special attention was given to both absolute recovery and entrapment efficiency. The results of optimized formulations showed a narrow size distribution with a polydispersity index near to 0.200. The particle sizes were on average 109.2 and 236.5nm to nanospheres and nanocapsules, respectively. In the best formulations the zeta potential was higher than 30 mV (in module) and the absolute recovery and entrapment efficiency were higher 82% and nearly 60%, respectively. The main variables were the quantity of the polymer and of the oil. Nanoparticles observed by the Scanning Electron Microscope depicted extremely spherical shape. In vitro release studies were performed through dialysis with continuous stream. Nanocapsules and nanospheres showed a similar pure diffusion release mechanism according to Korsmeyer-Peppas’s model.CNPqCAPESFAPES

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO
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