Non-Canonical Perturbation Theory of Non-Linear Sigma Models

We explore the O(N)-invariant Non-Linear Sigma Model (NLSM) in a different perturbative regime from the usual relativistic-free-field one, by using non-canonical basic commutation relations adapted to the underlying O(N) symmetry of the system, which also account for the non-trivial (non-flat) geometry and topology of the target manifold.Comment: 11 pages, 1 figure, LaTe

Design Optimization of a High Power LED Matrix Luminaire

This work presents a methodology for optimizing the layout and geometry of an m x n high power (HP) light emitting diode (LED) luminaire. Two simulators are used to analyze an LED luminaire model. The first simulator uses the finite element method (FEM) to analyze the thermal dissipation, and the second simulator uses the ray tracing method for lighting analysis. The thermal and lighting analysis of the luminaire model is validated with an error of less than 10%. The goal of the optimization process is to find a solution that satisfies both thermal dissipation and light efficiency. The optimization goal is to keep the LED temperature at an acceptable level while still obtaining uniform illumination on a target plane. Even though no optical accessories or active cooling systems are used in the model, the results demonstrate that it is possible to obtain satisfactory results even with a limited number of parameters. The optimization results show that it is possible to design luminaires with 4, 6 and up to 8 HP-LEDs, keeping the LED temperature at about 100 degrees C. However, the best uniformity on a target plane was found by the heuristic algorithm

Design Optimization of a High Power LED Matrix Luminaire

This work presents a methodology for optimizing the layout and geometry of an m x n high power (HP) light emitting diode (LED) luminaire. Two simulators are used to analyze an LED luminaire model. The first simulator uses the finite element method (FEM) to analyze the thermal dissipation, and the second simulator uses the ray tracing method for lighting analysis. The thermal and lighting analysis of the luminaire model is validated with an error of less than 10%. The goal of the optimization process is to find a solution that satisfies both thermal dissipation and light efficiency. The optimization goal is to keep the LED temperature at an acceptable level while still obtaining uniform illumination on a target plane. Even though no optical accessories or active cooling systems are used in the model, the results demonstrate that it is possible to obtain satisfactory results even with a limited number of parameters. The optimization results show that it is possible to design luminaires with 4, 6 and up to 8 HP-LEDs, keeping the LED temperature at about 100 degrees C. However, the best uniformity on a target plane was found by the heuristic algorithm

Developing and Comparing Indices to Evaluate Community Knowledge Building in an Educational Research Course

This paper implements a novel approach to analyzing the degree of Collective Cognitive Responsibility (CCR) in a Knowledge Building community, based on socioeconomic and scientometric measures. After engaging in Knowledge Forum (KF) discussions for one semester, 36 students identified impactful ideas in their portfolios, which were then used to develop their impact scores. These scores were then transformed and plotted along the Lorenz Curve and the Gini coefficient to visualize the degree of equidistribution of recognition in the community and, by extension, the degree of collective responsibility shared by members of the community. Additionally, students were classified into member roles based on the impact of their contributions, and we explored the flow of member roles across several discussion topics, based on Price's model of scientific production. Our results show convergence between peers' and teachers' ratings of impactful contributions, which both point to medium levels of collective responsibility in the community. In short, on the one hand, this procedure shows its sensitivity to detect communities that could not comply with the CCR principle. On the other hand, we discuss the necessity of reflective evaluation to address the pedagogical challenge of fostering collective responsibility for knowledge advancement and empowering novel students to take charge of their knowledge work at the highest levels

Higher-U(2,2)-spin fields and higher-dimensional W-gravities: quantum AdS space and radiation phenomena

A physical and geometrical interpretation of previously introduced tensor operator algebras of U(2,2) in terms of algebras of higher-conformal-spin quantum fields on the anti-de Sitter space AdS_5 is provided. These are higher-dimensional W-like algebras and constitute a potential gauge guide principle towards the formulation of induced conformal gravities (Wess-Zumino-Witten-like models) in realistic dimensions. Some remarks on quantum (Moyal) deformations are given and potentially tractable versions of noncommutative AdS spaces are also sketched. The role of conformal symmetry in the microscopic description of Unruh and Hawking's radiation effects is discussed.Comment: LaTeX, 30 pages, 2 figures, final version to appear in Class. and Quant. Gra

Almidón resistente: una fracción indigestible en los alimentos

Resistant starch (RS), the dietary starch that scape digestion in the small intestine, can yields up to 20% of the starch in cereal and legume products. Several fractions contribute to the total RS of foods: retrograded amylose, starch inaccessible to digestive enzymes because of mechanical barriers, chemically modified starch fragments, undigested starch due to α-amylase inhibitors and starch complexed with other food components. RS is formed in products processed following heat treatments (baking, extrusion, autoclaving, etc.). RS produces significant fecal bulking and is partially fermentable by anaerobic bacteria of the colon. On the other hand, the relation of resistant starch with the glucose and insulin response in human subjects is an important nutritional effect. RS analytical methods are reported.El almidón resistente (RS), fracción de almidón de la dieta que no es digerido en el intestino delgado, puede alcanzar hasta un 20% del almidón en productos derivados de cereales y legumbres. Varias fracciones contribuyen al contenido total de almidón resistente: amilosa retrogradada, almidón inaccesible físicamente a los enzimas digestivos, almidón indigestible debido a inhibición de α-amilasas y almidón complejado con otros constituyentes de los alimentos. El almidón resistente se forma en productos que han sufrido tratamientos térmicos (panificación, extrusión, autoclave, etc.) El RS aumenta el volumen de heces y es fermentado parcialmente en el colon por bacterias anaeróbicas. Igualmente, está relacionado con los niveles de glucosa en sangre y la respuesta de insulina en humanos. Se describen los métodos analíticos para su determinación

The role of PKC/ERK1/2 signaling in the anti-inflammatory effect of tetracyclic triterpene euphol on TPA-induced skin inflammation in mice

AbstractInflammation underlies the development and progression of a number of skin disorders including psoriasis, atopic dermatitis and cancer. Therefore, novel antiinflammatory agents are of great clinical interest for prevention and treatment of these conditions. Herein, we demonstrated the underlying molecular mechanisms of the antiinflammatory activity of euphol, a tetracyclic triterpene isolated from the sap of Euphorbia tirucalli, in skin inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in mice. Topical application of euphol (100μg/ear) significantly inhibited TPA-induced ear edema and leukocyte influx through the reduction of keratinocyte-derived chemokine (CXCL1/KC) and macrophage inflammatory protein (MIP)-2 levels. At the intracellular level, euphol reduced TPA-induced extracellular signal-regulated protein kinase (ERK) activation and cyclooxygenase-2 (COX-2) upregulation. These effects were associated with euphol's ability to prevent TPA-induced protein kinase C (PKC) activation, namely PKCα and PKCδ isozymes. Our data indicate that topical application of euphol markedly inhibits the inflammatory response induced by TPA. Thus, euphol represents a promising agent for the management of skin diseases with an inflammatory component

Birefringent Optofluidic Gratings

A set of parallel microfluidic channels behaving as a diffraction grating operating in the Raman-Nath regime has been fabricated and studied. The diffraction efficiency of such structure can be tuned by selecting a liquid with a particular refractive index and/or optical anisotropy. Alternatively the optical properties of the liquid can be characterised by measuring the diffraction efficiency and the state of polarization of the diffracted beam. In this work, the microfluidic channels under study have been filled with penicillin molecules dissolved in water. Due to the chirality of the penicillin, the liquid has been found to have circular birefringence of 2.14 × 10-7. The addition of the anisotropic liquid modifies the polarization properties of the microfluidic diffraction grating. The diffraction efficiency of the grating has been characterised for different probe beam wavelengths and states of polarization. Currently the diffraction efficiency of the device is low - 1.7%, but different approaches for its improvement have been discussed

Comparação morfofisiológica de rizóbios conservados pelas técnicas de liofilização e óleo mineral.

bitstream/item/111377/1/12-comparacao-alessandra.pd