Cosmic web alignments with the shape, angular momentum and peculiar velocities of dark matter haloes

We study the alignment of dark matter haloes with the cosmic web characterized by the tidal and velocity shear fields. We focus on the alignment of their shape, angular momentum and peculiar velocities. We use a cosmological N-body simulation that allows to study dark matter halos spanning almost five orders of magnitude in mass ($10^{9}$-$10^{14}$) $h^{-1}$$M_{\odot}$ and spatial scales of $(0.5$-$1.0)$ $h^{-1}$ Mpc to define the cosmic web. We find that the halo shape presents the strongest alignment along the smallest tidal eigenvector, e.g. along filaments and walls, with a signal that gets stronger as the halo mass increases. In the case of the velocity shear field only massive halos $>10^{12}$ $h^{-1}$$M_{\odot}$ tend to have their shapes aligned along the largest tidal eigenvector; that is, perpendicular to filaments and walls. For the angular momentum we find alignment signals only for halos more massive than $10^{12}$ $h^{-1}$$M_{\odot}$ both in the tidal and velocity shear webs where the preferences are for it to be parallel to the middle eigenvector; perpendicular to filaments and parallel to walls. Finally, the peculiar velocities show a strong alignment along the smallest tidal eigenvector for all halo masses; halos move along filaments and walls. In the velocity shear the same alignment is present but weaker and only for haloes less massive than $10^{12}$ $h^{-1}$$M_{\odot}$. Our results clearly show that the two different algorithms we used to define the cosmic web describe different physical aspects of non-linear collapse and should be used in a complementary way to understand the effect of the cosmic web on galaxy evolution.Comment: 14 pages, 5 figures, MNRAS accepte

Aspectos conflictivos en la aplicación de la deducción del Impuesto sobre el Valor Añadido

Treball Final del Màster Universitari en Gestió Financera i Comptabilitat Avançada (Pla de 2013). Codi: SRL031. Curs acadèmic 2013-2014El Impuesto sobre el Valor Añadido plantea, en su aplicación, diversos supuestos en los que se plantean diversas dudas y conflictos entre la Administración y los contribuyentes. El presente trabajo tiene como objetivo determinar y analizar estos casos en donde en numerosas ocasiones se produce cierta controversia en la aplicación de dicho impuesto. Concretamente, se recogen los supuestos más conflictivos y referidos a la deducción del Impuesto sobre el Valor Añadido en las declaraciones periódicas del obligado. La Administración es la que, a través de las leyes aprobadas por los representantes de los ciudadanos en el Parlamento, aplica una serie de pautas que deben seguirse para la correcta aplicación de un impuesto tan importante como es este. No obstante, debido algunas veces al no conocimiento de la ley y en otras, a una actuación premeditada, pero conociéndola, se producen discrepancias entre la forma de actuar que marca dicha ley y la actuación final del contribuyente. Queda, por lo tanto, una asignatura pendiente a superar que pasa por intentar reducir en la medida de lo posible la falta de neutralidad en el impuesto derivada en ocasiones de este tipo de conflictos en la aplicación de la deducción de este impuesto

TufFoam Density Variation through Radiography

TufFoam is a low density, high impact tolerant polyurethane foam with good high voltage breakdown developed at the Sandia National Laboratories. Identically shaped samples have been produced with various formulations and production conditions. Eight different variables were studied. Our aim is to compare the density variation of the material when produced and processed under distinct conditions. The density of TufFoam is determined using radiographic imaging. We extract the foam density by fitting the radiographic density of each step in a plastic step wedge with 10 steps from 0.1 to 1.0 inches and applying the resulting equation to convert each pixel in the radiograph to an image based on inches. A total of 28 samples were radiographed with a source to sample distance of approximately 53 inches. The 28 samples were separated into 12 different groups; each group of samples was produced under identical conditions. The results varied depending on the variables in which the samples were produced. We observed that when samples were fabricated under certain conditions the resulting images and histograms showed a uniform density distribution. When made under other conditions samples were produced with a non-uniform density distribution. Furthermore, certain variables resulted in samples with distinct and thicker skin layer compared to the interior portion of the sample. We will discuss the effect of the variables on the homogeneity and density of the samples

Case study: implementation of cleaner production as environmental strategy for hazardous waste minimization industry flexible plastic packaging

La implementación de la producción más limpia como estrategia ambiental para la minimización de residuos peligrosos en la industria de empaques plásticos flexibles define determinadas soluciones operativas además de tecnológicas aplicadas a los procesos, productos y servicios para lograr dentro de un sistema de gestión ambiental basado en el ciclo Planear- Hacer- Verificar- Actuar, enfocar 6 fases procedimentales con herramientas específicas basadas en matrices de análisis que permiten a la industria cumplir con las políticas de disminución de impactos ambientales por aspectos relacionados con la segregación de materiales o desechos de carácter peligroso, así mismo para reducir los costos asociados por la falta de planeación de los recursos y por supuesto generar procesos productivos de mayor eficiencia como eficacia que propendan por la conservación junto con el desarrollo sostenible. En general se logró la implementación de dos grandes aspectos que compensan y corrigen la actual problemática ambiental relacionada con los residuos peligrosos, basados con las buenas practicas operacionales así como las técnicas de minimización; para el primero corresponde soluciones como la coordinación entre departamentos, control de inventarios, almacenamiento y manipulación de materiales, prevención de fugas y derrames, mantenimiento preventivo, segregación de residuos, guías o manuales de operación además del tratamiento físico para residuos. Para el segundo aspecto modificación del proceso de producción, reducción del volumen y la recuperación.The implementation of cleaner production and environmental strategy for hazardous waste minimization in industry flexible plastic packaging defines certain operational solutions as well as technology applied to processes, products and services to achieve within an environmental management system based on the Plan-Do-Check- Act cycle, focus 6 procedural steps with specific tools based on analysis matrices that enable the industry comply with the policies of decreasing environmental impacts aspects segregation of waste materials or hazardous nature, and same to reduce the costs associated with the lack of planning of resources and of course generate more efficient production processes and efficiency which foster conservation with sustainable development. Overall the implementation of two major aspects that compensate and correct the current environmental problems related to hazardous waste, based with good operating practices and minimization techniques was achieved; the first corresponds to solutions such as coordination between departments, inventory control, storage and handling of materials, preventing leaks and spills, preventive maintenance, waste segregation, guidelines or operating manuals in addition to physical treatment to waste. For the second aspect of the production process modification, volume reduction and recovery

Dynamic Control Design LQR PI Vectorial of Remotely Operated Underwater Vehicl

Este Documento muestra el control LQR (Lineal Regulador cuadrático) PI (Integral Proporcional) Diseño vectorial, que está desarrollado para controlar la dinámica de un vehículo submarino operado remotamente ROV, para permitir que el vehículo siga una trayectoria horizontal de forma autónoma. Los resultados se muestran mediante simulaciones de seguimiento de trayectoria de ROV obteniendo resultados satisfactorios y cumpliendo con el objetivo de controlar la dinámica mientras sigue una trayectoria.Universidad Libre -- Facultad de ingeniería -- Ingeniería MecánicaThis Document shows the control LQR (Linear quadratic Regulator) PI (Proportional Integral)Vectorial design, which is developed to control the dynamic of a remote operated underwater vehicle ROV, to allow that the vehicle follow a horizontal trajectory autonomously . The results are showed through simulations of following the trajectory of ROV obtaining satisfactory results and complying with the objective to control the dynamic while follow a trajector

Multi-objective optimal power resources planning of microgrids with high penetration of intermittent nature generation and modern storage systems

Microgrids are self-controlled entities at the distribution voltage level that interconnect distributed energy resources (DERs) with loads and can be operated in either grid-connected or islanded mode. This type of active distribution network has evolved as a powerful concept to guarantee a reliable, efficient and sustainable electricity delivery as part of the power systems of the future. However, benefits of microgrids, such as the ancillary services (AS) provision, are not possible to be properly exploited before traditional planning methodologies are updated. Therefore, in this doctoral thesis, a named Probabilistic Multi-objective Microgrid Planning methodology with two versions, POMMP and POMMP2, is proposed for effective decision-making on the optimal allocation of DERs and topology definition under the paradigm of microgrids with capacity for providing AS to the main power grid. The methodologies are defined to consider a mixed generation matrix with dispatchable and non-dispatchable technologies, as well as, distributed energy storage systems and both conventional and power-electronic-based operation configurations. The planning methodologies are formulated based on a so-called true-multi-objective optimization problem with a configurable set of three objective functions. Accordingly, the capacity to supply AS is optimally enhanced with the maximization of the available active residual power in grid-connected operation mode; the capital, maintenance, and operation costs of microgrid are minimized, while the revenues from the services provision and participation on liberalized markets are maximized in a cost function; and the active power losses in microgrid´s operation are minimized. Furthermore, a probabilistic technique based on the simulation of parameters from their probabilistic density function and Monte Carlo Simulation is adopted to model the stochastic behavior of the non-dispatchable renewable generation resources and load demand as the main sources of uncertainties in the planning of microgrids. Additionally, POMMP2 methodology particularly enhances the proposal in POMMP by modifying the methodology and optimization model to consider the optimal planning of microgrid's topology with the allocation of DERs simultaneously. In this case, the concept of networked microgrid is contemplated, and a novel holistic approach is proposed to include a multilevel graph-partitioning technique and subsequent iterative heuristic optimization for the optimal formation of clusters in the topology planning and DERs allocation process. This microgrid planning problem leads to a complex non-convex mixed-integer nonlinear optimization problem with multiple contradictory objective functions, decision variables, and diverse constraint conditions. Accordingly, the optimization problem in the proposed POMMP/POMMP2 methodologies is conceived to be solved using multi-objective population-based metaheuristics, which gives rise to the adaptation and performance assessment of two existing optimization algorithms, the well-known Non-dominated Sorting Genetic Algorithm II (NSGAII) and the Multi-objective Evolutionary Algorithm Based on Decomposition (MOEA/D). Furthermore, the analytic hierarchy process (AHP) is tested and proposed for the multi-criteria decision-making in the last step of the planning methodologies. The POMMP and POMMP2 methodologies are tested in a 69-bus and 37-bus medium voltage distribution network, respectively. Results show the benefits of an a posteriori decision making with the true-multi-objective approach as well as a time-dependent planning methodology. Furthermore, the results from a more comprehensive planning strategy in POMMP2 revealed the benefits of a holistic planning methodology, where different planning tasks are optimally and simultaneously addressed to offer better planning results.Las microrredes son entes autocontrolados que operan en media o baja tensión, interconectan REDs con las cargas y pueden ser operadas ya sea en modo conectado a la red o modo isla. Este tipo de red activa de distribución ha evolucionado como un concepto poderoso para garantizar un suministro de electricidad fiable, eficiente y sostenible como parte de los sistemas de energía del futuro. Sin embargo, para explotar los beneficios potenciales de las microrredes, tales como la prestación de servicios auxiliares (AS), primero es necesario formular apropiadas metodologías de planificación. En este sentido, en esta tesis doctoral, una metodología probabilística de planificación de microrredes con dos versiones, POMMP y POMMP2, es propuesta para la toma de decisiones efectiva en la asignación óptima de DERs y la definición de la topología de microrredes bajo el paradigma de una microrred con capacidad para proporcionar AS a la red principal. Las metodologías se definen para considerar una matriz de generación mixta con tecnologías despachables y no despachables, así como sistemas distribuidos para el almacenamiento de energía y la interconnección de recursos con o sin una interfaz basada en dispositivos de electrónica de potencia. Las metodologías de planificación se formulan sobre la base de un problema de optimización multiobjetivo verdadero con un conjunto configurable de tres funciones objetivo. Con estos se pretende optimizar la capacidad de suministro de AS con la maximización de la potencia activa residual disponible en modo conectado a la red; la minimización de los costos de capital, mantenimiento y funcionamiento de la microrred al tiempo que se maximizan los ingresos procedentes de la prestación de servicios y la participación en los mercados liberalizados; y la minimización de las pérdidas de energía activa en el funcionamiento de la microrred. Además, se adopta una técnica probabilística basada en la simulación de parámetros a partir de la función de densidad de probabilidad y el método de Monte Carlo para modelar el comportamiento estocástico de los recursos de generación renovable no despachables. Adicionalmente,la POMMP2 mejora la propuesta de POMMP modificando la metodología y el modelo de optimización para considerar simultáneamente la planificación óptima de la topología de la microrred con la asignación de DERs. Así pues, se considera el concepto de microrredes interconectadas en red y se propone un novedoso enfoque holístico que incluye una técnica de partición de gráficos multinivel y optimización iterativa heurística para la formación óptima de clusters para el planeamiento de la topología y asignación de DERs. Este problema de planificación de microrredes da lugar a un complejo problema de optimización mixto, no lineal, no convexos y con múltiples funciones objetivo contradictorias, variables de decisión y diversas condiciones de restricción. Por consiguiente, el problema de optimización en las metodologías POMMP/POMMP2 se concibe para ser resuelto utilizando técnicas multiobjetivo de optimización metaheurísticas basadas en población, lo cual da lugar a la adaptación y evaluación del rendimiento de dos algoritmos de optimización existentes, el conocido Non-dominated Sorting Genetic Algorithm II (NSGAII) y el Evolutionary Algorithm Based on Decomposition (MOEA/D). Además, se ha probado y propuesto el uso de la técnica de proceso analítico jerárquico (AHP) para la toma de decisiones multicriterio en el último paso de las metodologías de planificación. Las metodologías POMMP/POMMP2 son probadas en una red de distribución de media tensión de 69 y 37 buses, respectivamente. Los resultados muestran los beneficios de la toma de decisiones a posteriori con el enfoque de optimización multiobjetivo verdadero, así como una metodología de planificación dependiente del tiempo. Además, los resultados de la estrategia de planificación con POMMP2 revelan los beneficios de una metodología de planificación holística, en la que las diferentes tareas de planificación se abordan de manera óptima y simultánea para ofrecer mejores resultados de planificación.Línea de investigación: Planificación de redes inteligentes We thank to the Administrative Department of Science, Technology and Innovation - Colciencias, Colombia, for the granted National Doctoral funding program - 647Doctorad

U.S. commercial electricity consumption

Commercial electricity usage exceeds that of industrial usage and is almost as large as residential electricity consumption in the United States. In this study, regional economic, demographic, and climatic data are used to analyze commercial electricity demand in the United States. Results indicate that total commercial demand for electricity is negatively related to price. In addition, the number of businesses and service income positively affect electricity demand for commercial use. The results are similar for equations estimated for kilowatt-hours demanded per business. The regional dummy variables exhibit different signs, which may occur due to climate factors because warm weather regions experience greater volumes of cooling degree-days, while cool weather regions observe larger amounts of heating degree-days. Although coefficients for the price of natural gas are positive, they do not satisfy the 5-percent significance criterion. The latter suggests that natural gas may not be a substitute good for electricity within the commercial sector of the U.S. economy.Commercial Electricity Consumption; Regional Economics

Grasping Wage Bargaining Power: trends, gaps and drivers

Treballs Finals del Màster d'Economia Laboral / Labour Economics, Facultat d'Economia i Empresa, Universitat de Barcelona. Curs: 2021-2022. Tutor: Héctor Sala LordaTo measure the productivity-wage gap correctly, I depart from the basic Insider-Outsider model and extend it to encompass a Wage Bargaining Power Index, which is fundamental for understanding labour markets. This index takes the value of 0 if workers are paid as little as possible and takes the value of 1 if they are paid the value they generate. In the first part, I find an index for Peruvian labour market which move around 0.26 in the period 2007-2019. Additionally, there is a clear gender gap, which favors men, who have an index ranging from 0.25 to 0.31, while the index for women fluctuates between 0.21 and 0.25. In the second part, I explore the main drivers and I find, in general, some positive effects on education and fixed-term contracts, and negative effects of being women, non-white, working in a small-enterprise, violation of labour rights, the job search rate and tax revenues paid. By gender, I find that while men are disadvantaged by their class status and race, education and fixed-term contracts empower women's wage bargaining power. However, working in a small business and the job search rate have a greater negative effect on women than on men

Stochastic angular momentum slews and flips and their effect on discs in galaxy formation models

The angular momentum of galactic discs in semi-analytic models of galaxy formation is usually updated in time as material is accreted to the disc by adopting a constant dimensionless spin parameter and little attention is paid to the effects of accretion with misaligned angular momenta. These effects are the subject of this paper, where we adopt a Monte-Carlo simulation for the changes in the direction of the angular momentum of a galaxy disc as it accretes matter based on accurate measurements from dark-matter haloes in the Millennium II simulation. In our semi-analytic model implementation, the flips seen the dark matter haloes are assumed to be the same for the cold baryons; however, we also assume that in the latter the flip also entails a difficulty for the disc to increase its angular momentum which causes the disc to become smaller relative to a no-flip case. This makes star formation to occur faster, specially in low mass galaxies at all redshifts allowing galaxies to reach higher stellar masses faster. We adopt a new condition for the triggering of starbursts during mergers. As these produce the largest flips it is natural to adopt the disc instability criterion to evaluate the triggering of bursts in mergers instead of one based on mass ratios as in the original model. The new implementation reduces the average lifetimes of discs by a factor of 2, while still allowing old ages for the present-day discs of large spiral galaxies. It also provides a faster decline of star formation in massive galaxies and a better fit to the bright end of the luminosity function at z = 0.Comment: 15 pages, 12 figures, MNRAS in pres

Galactic conformity measured in semi-analytic models

We study the correlation between the specific star formation rate of central galaxies and neighbour galaxies, also known as 'galactic conformity', out to 20 Mpc/h using three semi-analytic models (SAMs, one from L-GALAXIES and other two from GALFORM). The aim is to establish whether SAMs are able to show galactic conformity using different models and selection criteria. In all the models, when the selection of primary galaxies is based on an isolation criterion in real space, the mean fraction of quenched galaxies around quenched primary galaxies is higher than that around star-forming primary galaxies of the same stellar mass. The overall signal of conformity decreases when we remove satellites selected as primary galaxies, but the effect is much stronger in GALFORM models compared with the L-GALAXIES model. We find this difference is partially explained by the fact that in GALFORM once a galaxy becomes a satellite remains as such, whereas satellites can become centrals at a later time in L-GALAXIES. The signal of conformity decreases down to 60% in the L-GALAXIES model after removing central galaxies that were ejected from their host halo in the past. Galactic conformity is also influenced by primary galaxies at fixed stellar mass that reside in dark matter haloes of different masses. Finally, we explore a proxy of conformity between distinct haloes. In this case the conformity is weak beyond ~ 3 Mpc/h (<3% in L-GALAXIES, <1-2% in GALFORM models). Therefore, it seems difficult that conformity is directly related with a long-range effect.Comment: 15 pages, 7 figures. Accepted for publication in MNRA