Simulació del funcionament d’un molí fariner de mar a partir d’un model virtual 3d

La finalitat d’aquest projecte es proporcionar la documentació necessària per la reconstrucció del molí fariner de Vilanova i la Geltrú tal com era l’any 1800. Reconstruir el mecanisme impulsor d’aigua, l’edificació i tots els components que defineixen la construcció, de tal forma que podem extreure els plànols per la seva construcció. Comprovar i simular el moviment, per tal d’assegurar que la interacció entre els components es correcte i el moviment que defineix es viable. Tot això es realitza amb una documentació real de l’època a partir de la qual redefinim un model 3d virtual existent realitzat amb Catia. Es realitzen una sèrie de càlculs d’elements finits sobre el model 3D, per comprovar les sol·licitacions sobre els components més crítics, per tal de realitzar les modificacions necessàries per evitar problemes estructurals en el model. Per últim, es realitza un càlcul amb el software de simulació avançat femap, per veure la resposta de les pales a la força exercida, abans i després de realitzar una modificació sobre elles per veure el comportament que té aquest punt de la construcció. Tot plegat representa la reconstrucció del molí fariner d’en Francesc Terrés, tot assentant l’enginy de tal forma que queda enllestit per la seva actualització al segle XXI

Nonlinear Structural Analysis of an Icosahedron and its Application to Lighter than Air Vehicles Under a Vacuum

The concept that a structure is capable of producing buoyancy using an internal vacuum rather than a gas dates back to the 1600s; but material technology has restricted the construction of such concept for common geometries, such as the sphere. Different and often complex geometries compensate for the lack of light materials that provide the stiffness and strength needed. Therefore, this research looks at an Lighter than Air Vehicle (LTAV) in the form of an icosahedral frame/skin configuration using nonlinear finite element analysis in order to determine the structural response of such vehicle, its capacity to sustain a vacuum with both material technology that exists today and in the near future, and its buoyancy characteristics. The structural response is characterized with large displacements; where membrane behavior dominates the icosahedral skin response, generating geometric stiffening in the overall structure. It is shown that those displacements have minimal effect in the structures buoyancy, with no more than 4% reduction. Overall, the nonlinear analysis of the icosahedral structure provided tangible background on its behavior and the LTAV applicability. It is feasibly possible to actually manufacture this type of vehicle in the very near future depending upon newer materials with more advanced strength

Design and Analysis of Air-Stiffened Vacuum Lighter-Than-Air Structures

Lighter-than-air (LTA) systems have been developed for numerous applications and have taken several forms. Airships, aerostats, blimps, and balloons are all part of this family of systems, which uses Archimedes principle to achieve neutral and positive buoyancy in air by replacing an air volume with LTA gases. These lifting gases stiffen the otherwise compliant envelope structures, allowing them to sustain the pressure difference brought by the displaced air. The compliance of these structures is a byproduct of the weight requirement, materials and geometrical arrangement of which these structures are built from, typically resulting in dimensionalities that exhibit low or virtually non-existent in-plane bending stiffness. The former has constrained the development of LTA structures that utilize an internal partial vacuum, rather than a lifting gas, to achieve positive buoyancy, where the structure would be subjected to a pressure differential near atmospheric pressure. Given the above limitation, this research presents the development trajectory and structural characterization of air stiffened designs, which utilize air to shape and serve as the core of a set of enclosing envelopes. The development trajectory established a simulation framework that enables the structural characterization of air-stiffened designs under a variety of geometric and loading conditions. Such framework allowed for the development of finite element solutions that included geometric, fluid-structure and contact nonlinearities, with capacity for further generalization. Given the developed framework, the structural characterization of the Helical Sphere and Icoron air-stiffened designs demonstrated a reduction of material modulus and strength requirements compared to membrane-over-frame designs, and showed the capability of air-stiffened designs to be tailored for specific material strength limits

Chupa Chuparosas y Chupacabras

A Rascuache Nahual that uses therianthropy on the border between the US and Mexico border

Bonding Over Bondage: Slavery, Racial Complexities and Commonalities in New Orleans, 1803-1819

Different events in the nineteenth century have transformed America’s sociopolitical, physical and cultural landscape and contributed to the formation of an American identity based on political liberty, a concept that revolved around the notion of freedom. The concept of slavery, which was opposite of liberty, would be a powerful force throughout American history. As Reverend John A. Ryan explained, liberty “consists mainly of the right to engage in an occupation, to make contracts, and to acquire property. From the beginning of our history as a nation, the constitutions of the various states protected this sphere of liberty for members of the Caucasian race.”1 It has been an inherent part of American history that those of lighter skin tones had social benefits that those with darker skins did not; this type of social structure based off race and color would be instilled into the American psyche and be a major component of American life and is a major concept in this paper

ECG Biometric Recognition: Review, System Proposal, and Benchmark Evaluation

Electrocardiograms (ECGs) have shown unique patterns to distinguish between different subjects and present important advantages compared to other biometric traits, such as difficulty to counterfeit, liveness detection, and ubiquity. Also, with the success of Deep Learning technologies, ECG biometric recognition has received increasing interest in recent years. However, it is not easy to evaluate the improvements of novel ECG proposed methods, mainly due to the lack of public data and standard experimental protocols. In this study, we perform extensive analysis and comparison of different scenarios in ECG biometric recognition. Both verification and identification tasks are investigated, as well as single- and multi-session scenarios. Finally, we also perform single- and multi-lead ECG experiments, considering traditional scenarios using electrodes in the chest and limbs and current user-friendly wearable devices. In addition, we present ECGXtractor, a robust Deep Learning technology trained with an in-house large-scale database and able to operate successfully across various scenarios and multiple databases. We introduce our proposed feature extractor, trained with multiple sinus-rhythm heartbeats belonging to 55,967 subjects, and provide a general public benchmark evaluation with detailed experimental protocol. We evaluate the system performance over four different databases: i) our in-house database, ii) PTB, iii) ECG-ID, and iv) CYBHi. With the widely used PTB database, we achieve Equal Error Rates of 0.14% and 2.06% in verification, and accuracies of 100% and 96.46% in identification, respectively in single- and multi-session analysis. We release the source code, experimental protocol details, and pre-trained models in GitHub to advance in the field.Comment: 11 pages, 4 figure