Biomass-derived carbon materials for energy storage applications

Energy storage systems are an essential link in the implementation of renewable energies and in the development of electric vehicles, which are needed to reduce our dependence on fossil fuels and the emission of greenhouse gases. Various technologies have been proposed for energy storage based on different working principles, including lithium-ion batteries, emerging sodium-ion batteries and electric-double layer capacitors. Besides the quest for improving key aspects such as energy and power densities, current research efforts are devoted to foster the manufacturing of more environmentally friendly devices using sustainable materials. Carbon-based electrodes hold considerable promise in such terms due to their low cost, tailorable morphology and microstructure, and the possibility of processing them by direct carbonization of eco-friendly and naturally-available biomass resources. The main goal of this thesis is to develop carbon materials from biomass resources and study their applications as electrode for lithium-ion batteries, sodium-ion batteries and electric-double layer capacitors. En route towards that goal, it also aims at expanding our understanding of the microstructural changes of biomass-derived carbons with varying processing conditions and their effect on the electrochemical performance for each of these technologies. The first part of this work reports on the synthesis of graphitized carbon materials from biomass resources by means of an Fe catalyst, and the study of their electrochemical performance as anode materials for lithium-ion batteries (LIBs). Peak carbonization temperatures between 850 °C and 2000 ºC were covered to study the effect of crystallinity, surface and microstructural parameters on the anodic behavior, focusing on the first-cycle Coulombic efficiency, reversible specific capacity and rate performance. Reversible capacities of Fe-catalyzed biomass-derived carbons were compared to non-catalyzed hard carbon and soft carbons materials heated up to 2800 ºC. Moreover, in-situ characterization experiments were carried out to advance our understanding of the mechanisms responsible for catalytic graphitization. The second part of this work reports a comprehensive study on the structural evolution of hard carbons from biomass resources as a function of carbonization temperature (800 - 2000 ºC), and its correlation with electrochemical properties as anode materials for sodium-ion batteries (SIBs). Synchrotron X-ray total scattering experiments were performed and the associated atomic pair distribution function (PDF) extracted from the data to access quantitative information on local atomic arrangement in these amorphous materials at the nanoscale, as well as its evolution with increasing processing temperature. Then, electrochemical properties and the storage mechanisms involved on Na ions insertion into hard carbon structures at each characteristic potential regions were elucidated and correlated with microstructural properties. Finally, the third part of this work reports on the synthesis of nanostructured porous graphene-like materials from biomass resources using an explosion-assisted activation strategy by nitrate compounds and Ni as a graphitization catalyst. The thermal behavior during carbonization as well as the resulting microstructural and surface properties were evaluated at two different processing temperatures, 300 and 1000 ºC. Finally, their application as electrode materials for electric-double layer capacitors (EDLCs) and LIBs is investigated, with a view to their performance under high charge/discharge specific current densities experiments.Premio Extraordinario de Doctorado U

Timing of protectionism

Recent history gives us evidence of the different timing and results of the opening up of several economies. We present a model to explain this divergence. Accordingly with this evidence, we show that, provided the government prefers more competition than less competition irrespective of the .rms. nationality, essentially three concepts explain everything: The agent' degree of impatience, the gap between the domestic and the foreign technologies and the costs due to the political environment. In sharp contrast to the existing literature, we show that a temporal protectionism can be time consistent, and domestic firms adopt new technologies under it.Temporal Protectionism, Time Consistency, Bankruptcies

Impatience, International Competitiveness, and Political

In this paper we present a model that describes how historical political constraints by themselves, or in combination with a sufficient degree of impatience, may be the cause of bankruptcy in some industries when a closed economy is opened to foreign competition. The model assesses the behavior of two types of firms, impatient and patient, which may or may not adopt foreign technology. The costs involved are not only economic but also political. These political costs are, nonetheless, measured in monetary terms. At some moment, which depends on the political constraints, a third firm enters the market, the foreign one. Depending on the national firms’ degree of impatience and the costs associated with political constraints, Nash equilibria, in which one or even both firms–at the moment the economy is opened–have to shut down, exist. All these strategies result to be subgame perfect equilibrium. Further, as a by-product, our results shed new light on the topic of temporary protection: The degree of impatience, by itself, my be the reason of why temporary protection may o may not fail to induce firms to adopt advanced technologies, even if the threat of liberalization is credible; furthermore, if both firms are sufficiently patient, both firms adopt the new technology and temporary protection results to be operative in order to maximize social welfare, so this equilibrium pass the “renegotiation-proof” criterium (along the equilibrium path).

La historiografia autonómica en España: un balance.

Sin resume

New Strategies to Identify Susceptibility to Cardiotoxicity by Anthracyclines and Proteasome Inhibitors

[ES]En la primera parte de este estudio propusimos que diferencias en la longitud telomérica, así como diferentes niveles de expresión de miRNAs y proteínas implicadas en diferentes rutas de señalización podrían participar en la susceptibilidad a la CDA y se asociarían al daño histopatológico que se produce en la misma. Por tanto, serían subfenotipos moleculares de la CDA. Aquí, hipotetizamos que los genes que determinan dichos subfenotipos moleculares podrían contribuir a la heredabilidad perdida de la CDA; y formas alélicas de esos genes podrían ayudar a identificar a los pacientes susceptibles a la misma149. Además, pensamos que esos subfenotipos moleculares determinados en plasma, podrían servir como biomarcadores de la CDA en pacientes. En una segunda parte de este trabajo de tesis doctoral, llevamos a cabo un estudio preliminar con el fin de predecir la susceptibilidad a la cardiotoxicidad in vitro de los inhibidores del proteasoma solos y en combinación con inmunomoduladores y glucocorticoides, por ser los fármacos con los que habitualmente se utilizan en la clínica. El estudio se llevó a cabo en cardiomiocitos humanos derivados de células pluripotenciales inducidas (hiPSCs-CMs). En cuanto a las combinaciones elegidas, las determinamos en base a las establecidas en la clínica o en los ensayos clínicos que se desarrollan actualmente123,125. En ambos estudios el objetivo fue ser capaces de identificar pacientes susceptible

Economía rosquilla

Este trabajo es un resumen del libro la “economía rosquilla”. El interior de la economía rosquilla es una representación gráfica de los umbrales mínimos que todas las personas de una sociedad concreta deberían alcanzar en una serie de dimensiones que configuran la calidad de vida. Por otro lado, el techo ecológico está representado por el límite externo de la rosquilla, de forma que si una sociedad sobresale por encima, indica que está asumiendo un riesgo medioambiental. Entre estos dos límites, se sitúa el espacio seguro y justo de progreso. La autora nos ofrece toda una serie de propuestas y reflexiones sobre el papel del sector público, el mercado y las empresas, las familias, el sector financiero, los bienes comunes y el medio ambiente, para conseguir que las sociedades actuales desarrollen una economía que alcance unos mínimos sociales, respetando las fronteras medioambientales.Universidad de Sevilla. Grado en Finanzas y Contabilida

Globalization, De-Industrialization and Mexican Exceptionalism 1750-1879

Like the rest of the poor periphery, Mexico had to deal with de-industrialization forces between 1750 and 1913, those critical 150 years when the economic gap between the industrial core and the primary-product-producing periphery widened to such huge dimensions. Yet, from independence to mid-century Mexico did better on this score than did most countries around the periphery. This paper explores the sources of Mexican exceptionalism with de-industrialization. It decomposes those sources into those attributable to productivity events in the core and to globalization forces connecting core to periphery, and to those attributable to domestic forces specific to Mexico. It uses a neo-Ricardian model (with non-tradable foodstuffs) to implement the decomposition, and advocates a price dual approach, and develops a new price and wage data base 1750-1878. There were three forces at work that account for Mexican exceptionalism: first, the terms of trade and Dutch disease effects were much weaker; second, Mexico maintained secular wage competitiveness with the core; and third, Mexico had the autonomy to devise effective ways to foster industry. The first appears to have been the most important.

An Economic Model of Tax Compliance with Individual Morality and Group Conformity

This paper explores the evolution of the female participation in the industrial labor force in Mexico during the 20th century. It finds a Ushaped relation between female labor participation and income per capita. An econometric analysis is carried out for the textile industry during the period 1925-1934 and for the manufacturing industry during the period 1987-1999. Results show the existence of substantial regional differences in female participation in the labor market, and the variables that explain it, that diminished with time, and particularly during the period 1994- 1999. Results suggest the existence of different degrees of social stigma around female participation in the industrial sector in the different regions, that were more important during the first than during the second period studied. Finally, results suggest that women’s labor participation in the declining part of the U could be in part the result of greater unionization of the labor force, and that the structural transformation that took place in the Mexican industry as a result of the opening-up of the economy from 1985 on ( and more intensely after 1994) could be behind the increase in the labor participation of women observed during the 1987-1999 period.labor paticipation, gender, social stigma, regional divergence, regional convergence.

Porous Graphene-like Carbon from Fast Catalytic Decomposition of Biomass for Energy Storage Applications

A novel carbon material made of porous graphene-like nanosheets was synthesized from biomass resources by a simple catalytic graphitization process using nickel as a catalyst for applications in electrodes for energy storage devices. A recycled fiberboard precursor was impregnated with saturated nickel nitrate followed by high-temperature pyrolysis. The highly exothermic combustion of in situ formed nitrocellulose produces the expansion of the cellulose fibers and the reorganization of the carbon structure into a three-dimensional (3D) porous assembly of thin carbon nanosheets. After acid washing, nickel particles are fully removed, leaving nanosized holes in the wrinkled graphene-like sheets. These nanoholes confer the resulting carbon material with ≈75% capacitance retention, when applied as a supercapacitor electrode in aqueous media at a specific current of 100 A·g–1 compared to the capacitance reached at 20 mA·g–1, and ≈35% capacity retention, when applied as a negative electrode for lithium-ion battery cells at a specific current of 3720 mA·g–1 compared to the specific capacity at 37.2 mA·g–1. These findings suggest a novel way for synthesizing 3D nanocarbon networks from a cellulosic precursor requiring low temperatures and being amenable to large-scale production while using a sustainable starting precursor such as recycled fiberwood.Spanish Government Agency Ministerio de Economí a y Competitividad (MINECO) (grant number MAT2016-76526-R)

El impacto en la gestión pública con el resultado de las auditorías

El presenta estudio tiene como objetivo general evidenciar que mediante el desarrollo de las auditorias en el sector público se puede impactar en la gestión de las organizaciones en el mejoramiento de sus procesos y procedimientos y en el logro de sus objetivos, que de acuerdo a las necesidades del cliente deben ir ajustando con el propósito de la satisfacción del cliente interno y externo. La gestión por procesos es una forma de administrar las organizaciones y facilitar la toma de decisiones, al igual que incentiva el trabajo en equipo para lograr la interrelación de los mismos y así mismo la eficiencia y efectividad del uso de los recursos para un cumplimiento racional de los objetivos. La evaluación y control de procesos y procedimientos se realiza a través de auditorías que les ayuden a las empresas en el logro de sus objetivos a través del mejoramiento continuo tal como se refleja en las realizadas por la Contraloría General de la Republica, que permiten garantizar transparencia en los procesos a cargo además de modernizar y hacer más participativo el accionar de las organizaciones hacia la comunidad en generalThis paper has the general purpose of showing the benefit of Auditing in the public sector and how this management tool can bring a huge benefit to the improvement of process and procedures within these organizations, which will help them to reach their goals and to deliver a better service to both internal and external customers. Process management is a way of managing organizations to help on decision making, providing an environment for team work improvement that results in a more effective and efficient use of the resources. The evaluation and control of methods and procedures is performed through Audits with the purpose of helping the organizations to reach their goals thru continuous improvement as it was noticed on those performed by the ?Contraloria General de la Republica? that allow not only processes transparency, but also the involvement of the communit