Reestructuración urbana el trébol – la Marín: Centro de convenciones y servicios en la Tola

En el capítulo 1, realizamos un análisis de los diferentes sectores dentro de la zona centro - sur de Quito, los cuales son lugares con problemáticas únicas y potencialidades aprovechables para la elaboración del Trabajo de Fin de Carrera. Aquí se realiza una memoria fotográfica para la creación de una base de datos, realizamos también un análisis de usos de suelos, de valor histórico, identificación de edificaciones importantes, sistemas de movilidad, para luego escoger de entre todas las opciones, el sector en el que se propondrá la propuesta de intervención. En el capítulo 2 analizamos más detalladamente el factor social, económico e histórico del sector escogido, tomando referencias de estudios previos sobre datos demográficos, estadísticas de vivienda y grupos etarios. Realizamos un levantamiento tridimensional donde se ponga en evidencia la topografía del sector y cómo se produce la movilidad. En el capítulo 3, analizamos varias problemáticas del sector que puedan servir como punto de partida para la propuesta. Determinamos el carácter implícito y único de cada barrio, así como los puntos potenciales más importantes de cada uno de los sectores escogidos. Luego, haciendo uso de las teorías estudiadas en el taller, elaboramos un partido conceptual que engloba una resolución a gran escala de uno de los principales problemas del sector, y a partir de esto, generamos los sistemas y subsistemas de intervención urbana de los que se trata nuestra propuesta. En el capítulo 4, escogí un sector dentro de la propuesta urbana donde se implantará mi proyecto arquitectónico y realicé un análisis de las condicionantes topográficas, sociales, funcionales, climáticas, etc. de este terreno específico. Después de esto, se determinó el tipo de arquitectura con el que se debía intervenir, los conceptos fundamentales que dan el carácter del proyecto y las intenciones formales y espaciales. Luego determiné el carácter que le doy al sector mediante la implementación de actividades y servicios. A modo general, propuse una zonificación general en la que se observa la escala de apropiación arquitectónica del terreno y a partir de esto, genero los espacios en función a los conceptos que quiero aplicar en este proyecto. Una vez realizado esto, identifico el partido conceptual y arquitectónico y propongo una propuesta a nivel de anteproyecto en la que se identifiquen todos los factores que llegan desde la propuesta urbana hasta los conceptos y teorías que yo utilizo individualmente. Una vez efectuados todos estos pasos, procedo a determinar una materialidad para el proyecto, como se sostendrá y qué efectos quiero lograr con los materiales que voy a utilizar. En el capítulo 5, se realiza una descripción del producto arquitectónico terminado, en el que las decisiones conceptuales, formales y estructurales se presentan en la forma de planos, fotomontajes, detalles y renders, para dar cuenta de la espacialidad, los distintos espacios y las cualidades constructivas del proyecto

Interlayer vibrational hybrid normal mode enabling molecular chiral phonons

Organic/inorganic interfaces formed by monolayer substrates and conjugated molecular adsorbates are attractive material platforms leveraging the modularity of organic compounds together with the long-range phenomena typical of condensed matter. New quantum states are known to be generated by electronic interactions in these systems as well as by their coupling with light. However, little is still known about hybrid vibrational modes. In this work, we discover from first principles the existence of an infrared-active chiral phonon mode in a pyrene-decorated MoSe$_{2}$ monolayer given by the combination of a frustrated rotation of the molecule around its central axis and an optical mode in the substrate. Our results suggest the possibility to enable phonon chirality in molecular superlattices

Visualization and thermodynamic encoding of single-molecule partition functions

Ensemble averaging of molecular states is fundamental for the experimental determination of thermodynamic quantities. A special case occurs for single-molecule investigations under equilibrium conditions, for which free energy, entropy and enthalpy at finite-temperatures are challenging to determine with ensemble-averaging alone. Here, we provide a method to access single-molecule thermodynamics, by confining an individual molecule to a nanoscopic pore of a two-dimensional metal-organic nanomesh, where we directly record finite-temperature time-averaged statistical weights using temperature-controlled scanning tunneling microscopy. The obtained patterns represent a real space equilibrium probability distribution. We associate this distribution with a partition function projection to assess spatially resolved thermodynamic quantities, by means of computational modeling. The presented molecular dynamics based Boltzmann weighting model is able to reproduce experimentally observed molecular states with high accuracy. By an in-silico customized energy landscape we demonstrate that distinct probability distributions can be encrypted at different temperatures. Such modulation provides means to encode and decode information into position-temperature space or to realize nanoscopic thermal probes.Comment: 20 Pages Main text, 5 Figures. 10 Pages Annexed tex

Edge Phonon Excitations in a Chiral Self-Assembled Supramolecular Nanoribbon

By design, coupled mechanical oscillators offer a playground for the study of crystalline topology and related properties. Particularly, non-centrosymmetric, supramolecular nanocrystals feature a complex phonon spectrum where edge modes may evolve. Here we show, employing classical atomistic calculations, that the edges of a chiral supramolecular nanoribbon can host defined edge phonon states. We suggest that the topology of several edge modes in the phonon spectrum is nontrivial and thermally insulated from bulk states. By means of molecular dynamics, we excite a supramolecular bond to launch a directional excitation along the edge without considerable bulk or back-propagation. Our results suggest that supramolecular monolayers can be employed to engineer phonon states that are robust against backscattering, toward supramolecular thermal waveguides, diodes, and logics

Voltage-Driven Conformational Switching with Distinct Raman Signature in a Single-Molecule Junction

Precisely controlling well-defined, stable single-molecule junctions represents a pillar of single-molecule electronics. Early attempts to establish computing with molecular switching arrays were partly challenged by limitations in the direct chemical characterization of metalâEuro"moleculeâEuro"metal junctions. While cryogenic scanning probe studies have advanced the mechanistic understanding of current- and voltage-induced conformational switching, metalâEuro"moleculeâEuro"metal conformations are still largely inferred from indirect evidence. Hence, the development of robust, chemically sensitive techniques is instrumental for advancement in the field. Here we probe the conformation of a two-state molecular switch with vibrational spectroscopy, while simultaneously operating it by means of the applied voltage. Our study emphasizes measurements of single-molecule Raman spectra in a room-temperature stable single-molecule switch presenting a signal modulation of nearly 2 orders of magnitude

Atomic resolution with high-eigenmode tapping mode atomic force microscopy

Atomic surface structure imaging is instrumental for the understanding of surface-related phenomena. Here, we show that conventional tapping mode atomic force microscopy with high cantilever eigenmodes and subnanometer amplitudes allow routine atomic imaging at atmospheric pressures. We identify the reasons for failure of atomic resolution imaging employing low eigenmodes. Strong tip-surface interactions cause significant differences between the oscillatory behaviors of the inclination of the cantilever as detected by conventional instruments and of the vertical position of the tip, which prevents correct functioning of instrumental feedback control loops. However, high effective spring constants of high eigenmodes make it possible to overcome the problem. Furthermore, the combination of high effective elastic constants of high cantilever eigenmodes with the high flexibility of the cantilever substantially enhances the imaging stability, thereby universally allowing atomic imaging of solid surfaces in gaseous environments and at elevated temperatures. Demonstrated imaging examples include single sulfur vacancies at the surface of MoS2 crystals imaged at temperatures ranging from room temperature to 250°C and potassium ions on hydrophilic and highly adhesive muscovite mica surfaces. Moreover, the high imaging stability allows knocking atoms off the MoS2 surface by hard tapping, indicating the potential for ultrahigh resolution lithography.Peer Reviewe

Analysis of energy consumption in Colombia using the holt method

Energy production is constantly facing major challenges today, because despite initiatives to promote the insertion of renewable energy, electricity consumption has shown considerable growth in recent years. In order to use an instrument that facilitates forecasts and predictive processes for the design of strategic plans associated with energy management, the application of the Holt Method is proposed using data on electricity demand in Colombia, GDP per capita and industrial value added, making an analysis of the last 10 years, based on figures from the World Bank. The final results predict that energy consumption for the period 2018-2020 will be between 66,231 GWk and 66,885 GWk

Band structure modulation by methoxy-functionalization of graphene nanoribbons

Graphene nanoribbons (GNRs) are considered as potential candidates for next-generation electronic materials, and chemical functionalization can be an efficient method to modulate their electronic properties. This work presents a solution synthesis of methoxy-substituted GNRs through the Diels-Alder polymerization of a tetraphenylcyclopentadienone-based monomer bearing four methoxy groups, followed by oxidative cyclodehydrogenation. The methoxy-functionalization of the GNRs was unambiguously validated by FTIR and solid-state NMR analyses. Moreover, theoretical studies by ab initio calculations predicted both charge redistribution and structural distortion induced by the methoxy substitution, revealing reduction of both the bandgap and of the effective mass of charge carriers. Employing THz spectroscopy, we found that methoxy-substitution at the edges enhanced the photoconductivity of GNRs by a factor of similar to 25%, primarily due to the reduced charge effective mass

Photoresponse of supramolecular self-assembled networks on graphene–diamond interfaces

Nature employs self-assembly to fabricate the most complex molecularly precise machinery known to man. Heteromolecular, two-dimensional self-assembled networks provide a route to spatially organize different building blocks relative to each other, enabling synthetic molecularly precise fabrication. Here we demonstrate optoelectronic function in a near-to-monolayer molecular architecture approaching atomically defined spatial disposition of all components. The active layer consists of a self-assembled terrylene-based dye, forming a bicomponent supramolecular network with melamine. The assembly at the graphene-diamond interface shows an absorption maximum at 740 nm whereby the photoresponse can be measured with a gallium counter electrode. We find photocurrents of 0.5 nA and open-circuit voltages of 270 mV employing 19 mW cm−2 irradiation intensities at 710 nm. With an ex situ calculated contact area of 9.9 × 102 μm2, an incident photon to current efficiency of 0.6% at 710 nm is estimated, opening up intriguing possibilities in bottom-up optoelectronic device fabrication with molecular resolution