New physical principles of contact thermoelectric cooling

We suggest a new approach to the theory of the contact thermoelectric cooling (Peltier effect). The metal-metal, metal-n-type semiconductor, metal-p-type semiconductor, p-n junction contacts are analyzed. Both degenerate and non-degenerate electron and hole gases are considered. The role of recombination in the contact cooling effect is discussed by the first time.Comment: 8 pages, 8 figures, revtex

Análisis de señales de audio utilizando la transformada de Gabor

La transformada de Gabor es una caso especial de la transformada en tiempo corto de furier (STFT por sus siglas en inglés) la cual permite estimar las frecuencias de una señal en un determinando intervalo de tiempo. Para poder acotar la señal en estos intervalos, se utilizan funciones conocidas como funciones ventanas las cuales están determinadas en el dominio temporal y posibilitan el cálculo del espectrograma el cual es la gráfica de la densidad de energía de una señal definida en un plano tiempo-frecuencia. Cuando la ventana usada es una función Gaussiana, esta se conoce como la transformada de Gabor. El problema con este espectrograma es que dependiendo de la ventana escogida, los resultados podrían no ser claros y las conclusiones tomadas dependiendo de esta gráfica podrían ser erróneas. El interés de este trabajo es comparar algunas ventas de tiempo con la intención de determinar las características que hacen buena o no a las ventas. Además, se aplicará este espectrograma a una señal de audio con el objetivo de analizar las características que se pueden extraer de esta

Colombian Energy Market: Optimal Portfolio

This paper focuses on the study of an optimal portfolio in the Colombian Energy Market using the Artificial Intelligence techniques specifically, Fuzzy Modeling and Neural Networks. The methodology at first, is implemented using the Matlab Fuzzy Logic Toolbox and with the help of a script the process is automatized. Secondly, a Neural Network is implemented in Matlab and its results are compared with the ones obtained in the Matlab Neural Network Toolbox. The results of the Fuzzy model and the Neural Network are presented and conclusions of both techniques are discussed. Finally possible future work are proposed

Colombian Energy Market: An approach of Anfis and Clustering Techniques to an Optimal Portfolio

This paper focuses on the study of a first approach to an optimal portfolio in the Colombian Energy Market using Artificial Intelligence. Specifically, ANFIS and Clustering techniques are applied. The methodology is implemented using the Matlab Toolboxes for clustering and FIS generation. Te results are presented, as well as the analysis of them. A first approximation to an optimal portfolio obtained with this methodology is shown. Consequently, some conclusions of the different techniques available for the same purpose are discussed. Finally the future work is proposed

Elaboración del patrón básico del pantalón

Cartilla de la serie “confecciones industriales” en la que se describe cómo hacer el trazado de la parte delantera y trasera del pantalón para hombre en distintas tallas.Primer of the series "industrial clothing" which describes how to make the layout of the front and back of the pants for men in different sizes.Medidas de tallas o cintura, en relación con la caja -- Trazo del pantalón para hombre -- Delantero -- Pieza trasera -- Algunos diseños de bolsillos delanteros -- EvaluaciónPrimera ediciónna9 página

Elaboración de patrones básicos de pantalón corto y bermudas

Cartilla en la que se describen los procesos, materiales y métodos paso a paso para la elaboración de patrones para pantalones cortos y bermudas.Primer describing the processes, materials and step-by-step methods for developing patterns for shorts and shorts.Pantalón corto o short femenino -- Pieza trasera -- Tira de la cintura -- Pantalón bermudas -- Pieza traserana9 página

Symmetrical Observability of Kinematic Parameters in Symmetrical Parallel Mechanisms

This article presents an application of symmetry group theory in kinematic identification of parallel mechanisms of nlegs legs -- Kinematic Identification implies the estimation of the actual geometrical parameters (as opposed to nominal ones) of a physical mechanism -- For a symmetric mechanism, KI requires configuring sets of leg positions with symmetrical observability – This article presents as main contributions: (i) a conjecture that allows mapping the symmetries of the mechanism into the active-joint workspace, (ii) a set of necessary conditions to express leg parameters in coordinate systems which allow symmetrical observability, and (iii) a procedure for exploiting symmetries in pose selection for kinematic identification of symmetrical parallel mechanisms -- For the kinematic identification itself, we adopt a divide-and-conquer (DC) identification protocol -discussed by us in another publication- in which each leg of the mechanism is independently identified by using the inverse calibration method -- In this article we emphasize how to exploit the symmetries existent in (nlegs − 1) legs of the parallel mechanism allowing to apply to other legs the symmetry-transformed sample protocol used for the kinematic identification of a reference leg -- The symmetrical observability of sets of leg parameters allows to reduce the costs of the pose selection procedure by a factor of (1/nlegs) compared to a complete DC procedure in which the poses of each leg are selected independently -- The pose selection is carried out only for the reference leg -- For the (nlegs−1) remaining legs the poses are dictated by symmetry operations performed onto the poses of the reference leg -- An application of the symmetrical observability is presented through the simulated kinematic identification of a 3RRR symmetrical parallel mechanismPolytechnic School of the University of São PauloSitio webIndicaciones, Associação Brasileira de Métodos Computacionais em Engenharia, International Association for Computational Mechanics, International Congress and Convention Association, Conheça o São Paulo é Tudo de Bom, Embratur, PETROBRA

Hydrogels for 3D neural tissue models: understanding cell-material interactions at a molecular level.

The development of 3D neural tissue analogs is of great interest to a range of biomedical engineering applications including tissue engineering of neural interfaces, treatment of neurodegenerative diseases and in vitro assessment of cell-material interactions. Despite continued efforts to develop synthetic or biosynthetic hydrogels which promote the development of complex neural networks in 3D, successful long-term 3D approaches have been restricted to the use of biologically derived constructs. In this study a poly (vinyl alcohol) biosynthetic hydrogel functionalized with gelatin and sericin (PVA-SG), was used to understand the interplay between cell-cell communication and cell-material interaction. This was used to probe critical short-term interactions that determine the success or failure of neural network growth and ultimately the development of a useful model. Complex primary ventral mesencephalic (VM) neural cells were encapsulated in PVA-SG hydrogels and critical molecular cues that demonstrate mechanosensory interaction were examined. Neuronal presence was constant over the 10 day culture, but the astrocyte population decreased in number. The lack of astrocytic support led to a reduction in neural process outgrowth from 24.0 ± 1.3 μm on Day 7 to 7.0 ± 0.1 μm on Day 10. Subsequently, purified astrocytes were studied in isolation to understand the reasons behind PVA-SG hydrogel inability to support neural network development. It was proposed that the spatially restrictive nature (or tight mesh size) of PVA-SG hydrogels limited the astrocytic actin polymerization together with a cytoplasmic-nuclear translocation of YAP over time, causing an alteration in their cell cycle. This was confirmed by the evaluation of p27/Kip1 gene that was found to be upregulated by a twofold increase in expression at both Days 7 and 10 compared to Day 3, indicating the quiescent stage of the astrocytes in PVA-SG hydrogel. Cell migration was further studied by the quantification of MMP-2 production that was negligible compared to 2D controls, ranging from 2.7 ± 2.3% on Day 3 to 5.3 ± 2.9% on Day 10. This study demonstrates the importance of understanding astrocyte-material interactions at the molecular level, with the need to address spatial constraints in the 3D hydrogel environment. These findings will inform the design of future hydrogel constructs with greater capacity for remodeling by the cell population to create space for cell migration and neural process extension

Disciplina positiva para el fortalecimiento de la inteligencia emocional en los ni?os de transici?n B de la instituci?n educativa Instituto Tebaida

80 p. Recurso Electr?nicoEste proyecto de investigaci?n se enfoc? especialmente en la implementaci?n de un plan de aula basado en la disciplina positiva para el fortalecimiento de la inteligencia emocional basado en la disciplina positiva de los ni?os de transici?n B de la Instituci?n educativa Instituto Tebaida, de La Tebaida Quind?o fue dirigida a una poblaci?n de 28 ni?os. Cuyo objetivo principal fue fortalecer la Inteligencia Emocional a trav?s de un plan de aula basado en la disciplina positiva, lo que impuls? a la realizaci?n de este plan de intervenci?n fue observar que algunos ni?os presentaban dificultades para seguir las instrucciones, estos ni?os no trabajan casi en equipo con los otros compa?eros, tienden a ser bruscos y agresivos o con un vocabulario poco cortes, contestan antes de que la maestra termine de preguntar, cuando hacen actividades en clase con reglas no las cumplen ni esperan el turno, interrumpiendo constantemente, no miden las consecuencias da?ando los juguetes o herramientas de trabajo del aula de clase, generando indisciplina y distrayendo a los otros ni?os que est?n inmersos en las actividades. Por lo tanto se vio la necesidad de realizar actividades que fortalecieran la inteligencia emocional, adem?s, se abordaron investigaciones sobre disciplina positiva, inteligencia interpersonal e intrapersonal, donde se encontraron referentes te?ricos, que fueron la base principal para la elaboraci?n de esta investigaci?n. Palabras clave: Disciplina positiva, inteligencia emocional, metodolog?a.This research project is especially focused on the implementation of a plan of classroom based on positive discipline for strengthening emotional intelligence based on positive discipline of children transition B of the Educational Institution Institute Tebaida La Tebaida Quind?o was addressed to a population of 28 children. Whose main objective was to strengthen Emotional Intelligence through a plan classroom based on positive discipline, which prompted the realization of this plan of action was observed that some children had difficulty following instructions, these children do not work nearly team with other colleagues, tend to be abrupt and aggressive or with a little vocabulary cuts, answer before the teacher finished asking, when do activities in class rules do not comply or expect the turn, constantly interrupting, no measure damaging consequences toys or tools of the classroom, creating indiscipline and distracting the other children who are involved in activities. So was the need for activities that strengthen emotional intelligence, further research on positive discipline, interpersonal and intrapersonal intelligence, where theoretical framework, which were the main basis for the development of this research were found addressed. Keywords: Positive Discipline, emotional intelligence, methodology