Advances in Single Entity Electrochemistry for Semiconducting Nanocrystal Studies

The research in this thesis focuses on the electrochemical and photoelectrochemical behavior of semiconducting nanoparticles (NPs) as single entities. The primary goal of this work is to develop methods to detect individual NP collisions—specifically semiconducting NPs—and to characterize their electrons transfer processes. Semiconductors are relevant in photocatalytic applications, either as a direct solar energy harvester or in water and solvent remediation. Most of the current applications are related to these two general modes. In this work, the photooxidation of methanol on titanium dioxide NPs was our model of study. This photocatalytic reaction has applications as a solar energy harvester and water remediation. The reaction is also of fundamental interest. Moreover, the single entity study under photocatalytic conditions is an approach to the mesoscopic domain, which could improve our understanding of the properties of connectivity, assembly, aggregation, and mass transfer of electrons through a film of semiconductor material for its application in solar cells. Furthermore, this work discusses relevant topics in stochastic electrochemistry, such as mass transport of NPs, filtering effects, and photocatalysis processes on single entities. The main discussion focuses on the stochastic event signal, i.e., the nano-impact and the subsequent electron transfer, i.e., the faradaic processes. We investigated filtering frequencies (digital and instrumental), noise, frequency of collisions, and final nano transients (high-resolution experiments) to discuss signal processing effects. We used ZnO NPs as a model to understand NP mass transport and the relative contribution of migration and diffusion for metal oxides. We modeled this process with the well-known Nernst-Plank equation and a subsequent development on migration by Amatore et al. While observing Zn electrolysis on a ZnO NP, we discussed the rate of electrolysis of Zn into a mercury amalgam and the effect of the instrumentation on these measurements. In the last chapter, we reported our advance in TiO2 methanol photooxidation through a HeCd laser irradiation. Firstly, we discussed the model developed with the combination of Mie theory on spherical particles and photoelectrochemistry. Secondly, we described nano-collisions in different experimental setups, leading to different types of transitions—homogenized and spiked. Homogenized suspension, TiO2, NPs are suspended in the cell with a fixed concentration before any alignment or electrochemical measurement. In a spiked suspension, a concentrated colloidal suspension of TiO2 NPs is injected at a certain time in the i-t transient measurement after the alignment of the laser. We fully characterize two systems for the spiking technique but not for the homogenized suspension. Thirdly, we described and analyzed the electrochemical response on Pt/TiO2 decorated electrodes. Fourthly, we discussed the implications of correlating the Mie theory and the electrochemical transients, viz., the step current and their statistical distributions. Finally, this works studies a NP captured on 600 nm Pt electrodes to confirm the photocurrent delivered by a single NP with high-resolution experiments. These experiments provide insight into mechanisms and NP properties that have not been reported previously to the best of our knowledge

Potential For Cattle Grazing on Sheep Range in Southwest Utah

A study was conducted on pastures grazed by sheep in late winter at the Desert Experimental Range in southwest Utah. Estimates of plant cover and herbage production were obtained in 1977 and used to examine longterm trends in the vegetation. The nutritional value of the six most important species of the area was assessed by chemical analysis. In addition, a management strategy was developed for obtaining some utilization of the range during the spring and summer months without affecting the traditional winter use by sheep. Long-term records (since 1937) in cover suggest a modest increase in grasses and a decrease in shrub cover. But there are insufficient data to infer range condition and trend. Long-term herbage production data (since 1938) show a substantial increase in annual species over the last twenty years. The year-to-year variability is very high, apparently depending on the prevailing climate conditions. Grass production was less variable than shrub production. No significant difference (P Based on the nutritional analysis of forage and long-term records of climate and plant production, a management strategy was devised to make more efficient use of the salt-desert shrub vegetation. Climatic conditions will favor good forage production about four years out of ten. Perennial grasses, annuals, and winterfat (Ceratoides lanata) showed better response to favorable climatic conditions than the other species. It is proposed in this study that, in these years of high production, the range could be used by cattle in the spring or summer, and thereby al low occasional resting of mountain summer pastures. Such opportunistic summer grazing on the desert should not be detrimental to winter sheep grazing, but the plan would need to be field-tested on an experimental or trial basis to evaluate ecological responses to increased livestock use

Towards an institutional analysis of accounting change in the Royal Tobacco Factory of Seville

This paper is initially informed by an institutional sociological framework to analyze changes in accounting practices that took place in the Royal Tobacco Factory (RTF) of Seville during the period 1760-1790. We argue that the significantly greater development and use of accounting practices during that period can be linked to the move to the much larger and more purposefully built new factories, the decline in total tobacco consumption, and the pressure to increase revenue for the Spanish Crown while reducing production cost and maintaining high product quality to deter entry. These new accounting practices were developed in part with the intent of improving factory efficiency, but importantly, they enhanced the external legitimacy of the RTF in the face of the events mentioned above and contributed to the long survival of the RTF as a monopolist

El análisis de estados financieros de la Caja Trujillo para mejorar la toma de decisiones gerenciales

El desarrollo de la presente investigación tiene como objetivo demostrar que el análisis de los estados financieros en la Caja Trujillo, permite mejorar de manera significativa la toma de decisiones gerenciales , estableciendo el grado de incidencia en el uso por parte de los gerentes y directivos en la toma de decisiones gerenciales para prever en gran parte los problemas financieros que se presentan en “La Caja Trujillo”, tales como: falta de liquidez, recuperación de cartera, márgenes bajos, entre otros, y por consiguiente su crecimiento sostenido y ordenado y determinar que el análisis de los Estados Financieros de la Caja Trujillo 2010 - 2011 permitió determinar la situación económica financiera de la empresa. Para esta investigación , dada la naturaleza del estudio la unidad de análisis estuvo conformada por la población de gerentes de la alta dirección involucrados con la toma de decisiones dentro de la Caja Trujillo, a fin de obtener información sobre todos los aspectos relacionados con la investigación , se efectuó el análisis de los estados financieros, políticas memorias e información coadyuvante de la Caja Trujillo que nos revele información de las variables en estudio (Manual de Organización y Funciones, directivas y otras), información bibliográfica (libros, textos, tesis, trabajos de experiencia profesional, monografías, etc.); así como los diversos aspectos relacionados con la investigación. La mayoría de los gerentes encuestados está de acuerdo en que conocen y utilizan las razones financieras y que esta información es elaborada mensualmente en la Caja. Los encuestados opinan que la toma de decisiones con estas herramientas se realiza sobre todo para atender operaciones importantes y que el conocimiento de información financiera es indispensable para una mejor toma de decisiones en el crecimiento de los negocios y que el Balance General y el Estado de resultados son las principales herramientas financieras con los que cuentan. En tal virtud, el presente trabajo demuestra que el análisis de los estados financieros en la Caja Trujillo, permite mejorar de manera significativa la toma de decisiones gerenciales estableciendo el grado de incidencia en el uso por parte de los gerentes y directivos y determinar que el análisis de los Estados Financieros de la Caja Trujillo 2010 - 2011The development of the present investigation aims to demonstrate that the analysis of the financial statements in the Caja Trujillo, allows you to significantly improve managerial decision making, establishing the degree of incidence in the use on the part of managers, and executives in managerial decision making to provide for in large part the financial problems that are presented in Caja Trujillo, such as: Lack of liquidity, portfolio recovery, low margins, among others, and therefore its sustained growth and orderly and determine that the analysis of the Financial Statements of the Caja Trujillo 2010 - 2011 has allowed us to determine the financial situation of the company. For the purpose of this investigation, given the nature of the study, the unit of analysis was composed of the population of managers of the top management involved with decision-making within the Caja Trujillo, in order to obtain information on all aspects related to the research, the analysis was made of the financial statements, policy reports and information of the adjuvant Trujillo Box that we disclose information of the variables under study (Manual of Organization and roles, policies, and other), bibliographic information (books, texts, thesis, work of professional experience, monographs, etc. ); as well as the various aspects related to the investigation. The majority of managers surveyed agree that know and use financial ratios, and that this information is compiled monthly in the Caja Trujillo. Respondents believe that the decision-making with these tools is carried out primarily to meet major operations and that the knowledge of financial information is essential for a better decision-making in the growth of the business and that the overall balance and the State of results are the main financial tools that are available. As such, the present work shows that the analysis of the financial statements in the Caja Trujillo , allows significantly improve managerial decision making by the degree of incidence on the use by the managers and directors and determine that the analysis of the Financial Statements of the Caja Trujillo 2010 - 2011.Tesi

Spatiotemporal analysis of the atmospheric and surface urban heat islands of the Metropolitan Area of Toluca, Mexico

The growth of urban populations around the globe is undeniable and consolidates in Latin America and the Caribbean, which nowadays is considered the most urbanized region in the world, for almost 80% of its population lives in cities (UN HABITAT 2012). However, many cities expanded without taking into consideration a proper planning that ensured the population’s quality of life. The expansion of the city modified land use and land cover and changed the albedo of the surface as the coverage of green areas decreased, and with this evapotranspiration, wind regime and surface runoff modified; besides, the sources of anthropogenic heat increased (Oke 1987; Lo´pez et al. 1993; Ferna´ndez and Martilli 2012). This impacts the regional conditions of climate, generating a local urban weather. According to Romero et al. (2010) ‘‘Urban climate comes from unnoticed and intentional transformations introduced into local and regional climates, which directly relate with the social construction of spaces and places.’’ All urban climates present common characteristics, being urban heat island its main feature (Oke 1987; Lo´pez et al. 1993; Monta´vez et al. 2000). An urban heat island is defined as an urban area with higher temperature conditions than neighboring non-developable areas (Voogt and Oke 2003). There are two sorts of urban heat islands. The first, atmospheric urban heat island (UHI), represents the differences in air temperature between urban and rural areas. The second, known as surface urban heat island (SUHI), shows termal differences between artificial surfaces (such as asphalt and rooftops) and the natural ones (such as vegetation and cultivations) (Ferna´ndez and Martilli 2012). The most significant when analyzing a heat island features is the shape, intensity and variations in space and time (Lo´pez et al. 1993; Voogt 2008).The dynamic of consolidation of urban areas in Latin America has allowed that almost 80% of the population concentrates in cities; this has produced changes in land covers and modified regional climate, propitiating the appearance of urban heat islands. The Metropolitan Area of Toluca, State of Mexico, Mexico, holds the fifth national place in population size and experiences this process, because of this, the objective is to analyze and compare the spatiotemporal characteristics of the atmospheric urban heat island obtained from data gathered from 12 urban and rural weather stations with the surface urban heat island obtained from the digital processing of four Landsat 8 images. Results show the year-round presence of night-time atmospheric urban heat islands, which reach a peak in autumn (up to 6 _C). Daytime atmospheric urban heat islands occur in summer and autumn with a maximum intensity of 4 _C. For their part, surface urban heat islands occur in spring, summer and autumn and reach maximums of 19 _C in intensity. A strong correlation was found between wetness and Surface temperature (coefficient of determination, 0.8) in spring and winter. Soil wetness directly impacts the formation of weak urban heat islands in dry season, and intense ones in wet season, while the green areas and the winds affect the spatial distribution of the same.Universidad Autónoma del Estado de México - CONACY

Weight-preserving isomorphisms between spaces of continuous functions: The scalar case

Let F be a finite field (or discrete) and let A andBB be vector spaces of F-valued continuous functions defined on locally compact spaces X and Y , respectively. We look at the representation of linear bijections H:A⟶B by continuous functions h:Y⟶X as weighted composition operators. In order to do it, we extend the notion of Hamming metric to infinite spaces. Our main result establishes that under some mild conditions, every Hamming isometry can be represented as a weighted composition operator. Connections to coding theory are also highlighted.The rst and third listed authors acknowledge partial support by the Generalitat Valenciana, grant code: PROMETEO/2014/062; and by Universitat Jaume I, grant P1·1B2012-05

On fuzzy uniformities induced by a fuzzy metric space

[EN] Different types of fuzzy uniformities have been introduced in the literature standing out the notions due to Hutton, Hohle and Lowen. The main purpose of this paper is to study several methods to endow a fuzzy metric space (X, M, *), in the sense of George and Veeramani, with a probabilistic uniformity and with a Hutton [0, 1](-quasi)-uniformity. We will show the functorial behavior of these constructions as well as its relation with respect to Lowen's functors and Katsaras's functors, which establish a relationship between the categories of probabilistic uniformities and Hutton [0, 1](-quasi)-uniformities with the category of classical uniformities respectively. Furthermore, we also study the fuzzy topologies associated with these fuzzy uniformities. (C) 2017 Elsevier B.V. All rights reserved.The first named author acknowledges the support of the grants MTM2015-63608-P (MINECO/FEDER, UE) and IT974-16 (Basque Government).The second named author is supported by the grant MTM2015-64373-P (MINECO/FEDER, UE).Gutierrez Garcia, J.; Rodríguez López, J.; Romaguera Bonilla, S. (2018). On fuzzy uniformities induced by a fuzzy metric space. Fuzzy Sets and Systems. 330:52-78. https://doi.org/10.1016/j.fss.2017.05.001S527833

Representation of group isomorphisms I

Let G be a metric group and let Aut(G) denote the automorphism group of G. If A and B are groups of G-valued maps defined on the sets X and Y , respec- tively, we say that A and B are equivalent if there is a group isomorphism H: A ! B such that there is a bijective map h: Y ! X and a map w: Y ! Aut(G) satisfy- ing Hf(y) = w[y](f(h(y))) for all y 2 Y and f 2 A. In this case, we say that H is represented as a weighted composition operator. A group isomorphism H defined between A and B is called separating when for each pair of maps f; g 2 A satisfying that f-1(eG)[g-1(eG) = X, it holds that (Hf)-1(eG)[(Hg)-1(eG) = Y . Our main result establishes that under some mild conditions, every separating group isomor- phism can be represented as a weighted composition operator. As a consequence we establish the equivalence of two function groups if there is a biseparating isomorphism defined between them

On the design of Aircraft Electrical Structure Networks

As part of the technology research engaged in the EU Clean Sky 1 project, we present in this paper an electrical structure network (ESN) designed to prevent the impact on an electronic equipment of unwanted voltage drops appearing when nonmetal composite materials are used for grounding. An iterative process has been followed to reach an optimal tradeoff solution meeting all the aircraft requirements: structural, safety, low weight, electrical, etc. Guidelines on the design of a low-impedance metal ESN, to minimize the inductive behavior of the power distribution network, are outlined in this paper. To this end, we employ the UGRFDTD simulation tool, combining finite-difference time domain to analyze the general EM problem, and a multiconductor transmission-line network to handle internal coupling between cables running along coinciding routes. The capability of this tool to create time-domain snapshots of surface currents is shown to provide a useful way to optimize the ESN, thanks to the insight gained on the physics of the problem.This work was supported from the European Community Seventh Framework Program FP7/2008-2014 under Grant CSJU-GAM-GRA- 2008-01 (Clean Sky 1 project), and from the Projects TEC2013-48414-C3- 01 and TEC2015-68766-REDC (MINECO, Spain), P12-TIC-1442 (Junta de Andalucia, Spain), Alhambra-UGRFDTD (AIRBUS DS), and by the CSIRC alhambra.ugr.es supercomputing cente