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Proposed mechanisms for the oxidation of methane into methyl hydrogen sulfate with transition metal species of vanadium or silver
No full textMethane is a gaseous chemical that can be converted into chemicals of interest useful to industry. However, the grand challenge in methane functionalization is the low reactivity of
methane combined with the very high reactivity of its products. The high reactivity of its products
leads to overoxidation, which in turn leads to low generation of products of interest since over
oxidation leads to the formation of carbon dioxide. The goal of my research projects hereafter is
to selectively oxidize methane into the chemical methyl hydrogen sulfate (MHS), which can be
hydrolyzed into the commodity chemical of methanol. This is done by combining using transition
metals catalysts coupled with electrochemistry in a two-chamber electrochemical system.
Moreover, another aspect of my projects has been to propose electrochemical mechanisms for the
electrochemical reactions. The first part of my dissertation focuses on using a vanadium molecular
catalyst (chapter 2) to selectively oxidize methane electrocatalytically into MHS. Similarly, the
second part of this dissertation focuses on the selective oxidation of methane into MHS by using
a molecular silver catalyst (chapter 3). Both research projects of vanadium and silver molecular
catalysts both use electrochemistry as the driving force at ambient conditions of room pressure and
room temperature, however, the electrolyte used in the chemical reactions is not mild. The
electrochemical reaction used 98% concentrated sulfuric acid. While room pressure and
temperature is a big focus of the projects, there are studies in the research projects that utilize
elevated pressures and temperatures. The use of elevated temperatures and pressures allows us to
conduct experiments, which can give us an insight into the electrochemical mechanism that is
occurring during the electrolysis reactions. To my knowledge, methane oxidation at room
temperature and room pressure had not been seen before with a homogenous catalyst, so the
innovation of my project is successfully proving that it is possible to oxidize methane at ambient
conditions with a homogenous catalyst while proposing an electrochemical mechanism for the
reactions
Albertas Vijūkas-Kojalavičius in the Society of Jesus
No full textAtkreipęs dėmesį j tą aplinkybę, kad Alberto Kojalavičiaus darbai žinomi, tačiau jo asmenybė tebeskendi šešėlyje, autorius pateikia šio žymaus XVII a. teologo, pedagogo, istoriko ir rašytojo biografiją. Sausi duomenys apie vienais ar kitais metais eitas pareigas - tai bemaž ir viskas, ką iki šiol visuomenė žino apie tėvą Kojalavičių. Remdamasis kai kuriais Jėzaus Draugijos Romos archyvo šaltiniais (metiniais katalogais ir nekrologu), straipsnio autorius pristato Alberto Kojalavičiaus asmenybę ir ją supusią aplinką. Kokiomis dorybėmis pasižymėjo Jėzaus draugu pasiryžęs būti tėvas Albertas? Kokių žmonių draugija Lietuvos jėzuitų provincijoje jį supo ir lydėjo penkis dešimtmečius studijuojant, dėstant, vadovaujant ir apaštalaujant? Tokie klausimai keliami šiame straipsnyje ir į juos duodami argumentuoti atsakymai. Pabaigoje pateikiamas lotyniškas Kojalavičiaus nekrologo tekstas, parengtas pagal dokumentą, saugomą Jėzaus Draugijos Romos archyve. Reikšminiai žodžiai: Albertas Vijūkas-Kojalavičius; Jėzaus Draugija; 17 amžius; Lietuvos jėzuitų provincija; Vilniaus jėzuitų akademija; Albertas Vijūkas-Kojalavičius; History of Lithuania (17th century); The Jesuit province of Lithuania; The Society of JesusThe author stresses the issue of how Albertas Kojalavičius's personality remains in obscurity in spite of the fame of his works. The article presents a biography of this well-known 17th century theologist, educationalist, historian and writer. On the basis of some sources from the Roman archive of the Society of Jesus (annual catalogues and an obituary), the author describes Albertas Kojalavičius's personality and the environment he lived in. What virtues did Father Albertas possess? What people surrounded him in the Jesuit province of Lithuania during the fifty years of studying, teaching, administrative and apostolic work? The current article raises these questions and endeavours to answer them substantially. The final part of the article includes the Latin text of Kojalavičius's obituary compiled on the basis of the document kept in the Roman archive of the Society of Jesus
Ritual, performatividad y resistencia en la obra fotográfica de Alberto Turok
No full textabstract: The indigenous communities of Chiapas, Mexico, have long manifested resistance to oppression and discrimination. This study centers on the analysis of Chiapas: el fin del silencio (1998) by Alberto Turok, connecting the work of the photographer to the problems faced by indigenous people in the region, such as inequality and marginalization. Race, class, gender, and globalization, in addition to the emergence of the Ejército Zapatista de Liberación Nacional (EZLN), are essential factors to the discourse of resistance. EZLN, an armed indigenous group in Chiapas, led by its famed leader, Subcomandante Marcos, clearly opposed the implementation of the North American Free Trade Agreement (NAFTA). In examining resistance, ritual, and performance, the photography of Turok serves as testimony of the struggles of indigenous people and the relevance it has for a diverse Mexican society.Dissertation/ThesisM.A. Spanish 201
Structural changes in metals consumption
No full textFor 15 years the metals market has been characterized by slow growth - in some cases, even decline - in consumption. To test the proposition that structural changes in demand were the main cause of the slowdown, the author - drawing on U.S. data - uses an extended metals demand model that recognizes energy, labor, capital, and other materials as major inputs. The traditional model explains metals consumption in terms only of output and the prices of metal and its substitutes. It is inadequate to address the issue of structural change because it ignores other factors of production, such as energy, which have experienced dramatic changes. With the extended model, the null hypothesis of no structural change cannot be rejected for most metals. With the conventional model, the null hypothesis of no structural change is strongly rejected. Results with the extended model show that the downturn can be explained mostly by changes in the input variables, particularly such nonmetal inputs as capital and energy, which are much more important cost items than metals and have undergone drastic cost changes over the period.Environmental Economics&Policies,Economic Theory&Research,Montreal Protocol,Mining&Extractive Industry (Non-Energy),Primary Metals
Electrical characterization of the temperature dependence in CdTe/CdS heterojunctions deposited <i>in-situ</i> by pulsed laser deposition
No full textThe I-V and C-V characteristics of CdTe/CdS heterojunctions deposited in-situ by Pulsed Laser Deposition (PLD) were evaluated. In-situ deposition enables the study of the CdTe/CdS interface by avoiding potential impurities at the surface and interface as a consequence of exposure to air. The I-V and C-V characteristics of the resulting junctions were obtained at different temperatures, ranging from room temperature to 150 °C, where the saturation current (from 10⁻⁸ to 10⁻⁴A/cm²), ideality factor (between 1 and 2), series resistance (from 10² to 10⁵ Ω), built-in potential (0.66-0.7 V), rectification factor (∼10⁶), and carrier concentration (∼10¹⁶ cm⁻³) were obtained. The current-voltage temperature dependence study indicates that thermionic emission is the main transport mechanism at the CdTe/CdS interface. This study also demonstrated that the built-in potential (V_{bi}) calculated using a thermionic emission model is more accurate than that calculated using C-V extrapolation since C-V plots showed a V_{bi} shift as a function of frequency. Although CdTe/CdS is widely used for photovoltaic applications, the parameters evaluated in this work indicate that CdTe/CdS heterojunctions could be used as rectifying diodes and junction field effect transistors (JFETs). JFETs require a low PN diode saturation current, as demonstrated for the CdTe/CdS junction studied here. © 2018 Author(s).NSF CAREER Award under the NSF Award ECCS-1653343Erik Jonsson School of Engineering and Computer Scienc
Cash flow or income? : the choice of base for company taxation
No full textConsiderable interest has been expressed in recent years by tax theorists as well as practitioners, for the taxation of companies based on their cash flow. Unlike the equity-income tax base, which requires the deductibility of economic depreciation and debt financing costs, the cash-flow base expenses capital at the point of purchase, eliminating the need for the subsequent costing of this capital. This paper raises some of the issues that would arise in trying to implement a company tax either in the form of an indexed equity-income or a cash-flow tax. Issues raised include: (i) administrative complexity; (ii) international tax coordination and competition; and (iii) transition problems. In a closed economy the cash-flow tax seems a simple, efficient form of company taxation, administratively straightforward and neutral with regard to investment decisions. The more complicated equity-income tax is harder to defend in a closed economy.Economic Theory&Research,Public Sector Economics&Finance,Environmental Economics&Policies,Banks&Banking Reform,International Terrorism&Counterterrorism
Maria Quitéria de Jesus: história e cinema
No full textThe author examined the biography of Maria Quitéria in order to write the script for a historical film. From this angle he tries to analyse the conception of history transmitted by the character
Fortalecimiento de la convivencia escolar y mejoramiento académico institucional generando un plan de acción en el colegio san Alberto magno
No full textEn el colegio San Alberto Magno de la ciudad de Barranquilla se vivencian múltiples contextos que replican la realidad del medio ambiente en que se desempeña su labor, es un observatorio en el cual se puede divisar con nitidez el comportamiento y las relaciones que se experimentan dentro de la comunidad educativa y donde el personal docente y administrativo se enfrenta a un reto de enormes dimensiones como lo es moldear y modelar a una generación de estudiantes con todas las responsabilidades y compromisos que ello conlleva. El tema de la convivencia escolar resulta esencial pues unas relaciones interpersonales armónicas, propicias, edificantes y positivas dentro de la comunidad educativa son un requisito sine qua non para un proceso integral de mejora académica. El autor del presente texto, como director del Colegio San Alberto Magno, ha tenido la oportunidad de conocer de primeramano las vicisitudes y necesidades propias de esta institución educativa ante lo cual considera primordial poner en práctica un plan de acción para fortalecer la convivencia escolar al reconocer su relación trascendental; con base en la filosofía de Santo Tomas de Aquino como en el pensamiento de Paulo Freire se busca consolidar una nueva visión pedagógica que incorpore las ideas de que cada ser humano enseña y aprende convirtiéndose en sujeto liberador (Freire, 2006), aportando esta visión desde el campo de la pedagogía, y de que, a partir de Santo Tomas, se logre contemplar la totalidad del ser trascendente, se conciba al ser humano como hijo de Dios que siempre tiende a la búsqueda de la verdad y la sabiduría que finalmente es el mismo Dios, desde una perspectiva espiritual y trascendental desde la cual considerar al ser humano, al ser la educación tan necesaria para el hombre, pues sin ella no daría cumplimiento pleno a su ser. Finalmente, se hace una caracterización de la población estableciendo su percepción sobre la convivencia y poder llegar a la construcción e implementación del “Diseño de la propuesta de convivencia” que tuviera en cuenta los cuatro pilares del aprendizaje señalados por Delors (1996): saber conocer, saber hacer, saber ser, saber convivir; la presente estrategia tuvo como eje central el desarrollo humano desde la concepción de Santo Tomás de Aquino como desde la de Paulo Freire, e identificó al sujeto educable como un estudiante pluridimensional, en razón de lo cual no sólo hay que trabajar en un currículo academicista que privilegie los contenidos cognitivos, sino en desarrollar otras habilidades que posibiliten la potenciación de su ser como persona: con valores, emociones y un sentido preminente de la alteridad, de la otredad,In the San Alberto Magno school in the city of Barranquilla, multiple contexts are experienced that replicate the reality of the environment in which its work is carried out, it is an observatory in which you can clearly see the behavior and relationships that are experienced within the educational community and where the teaching and administrative personnel face a challenge of enormous dimensions, such as shaping and modeling a generation of students with all the responsibilities and commitments that this entails. The issue of school coexistence is essential because harmonious, favorable, uplifting and positive interpersonal relationships within the educational community are a sine qua non requirement for a comprehensive process of academic improvement. The author of this text, as director of the Colegio San Alberto Magno, has had the opportunity to know firsthand the vicissitudes and needs of this educational institution, which he considers essential to implement an action plan to strengthen school coexistence by recognizing their transcendental relationship; Based on the philosophy of Santo Tomas de Aquino as well as on Paulo Freire's thinking, the aim is to consolidate a new pedagogical vision that incorporates the ideas that each human being teaches and learns by becoming a liberating subject (Freire, 2006), contributing this vision from the field of pedagogy, and that, from Santo Tomas, it is possible to contemplate the totality of the transcendent being, the human being is conceived as a child of God who always tends to the search for the truth and wisdom that finally is the God himself, from a spiritual and transcendental perspective from which to consider the human being, being the education so necessary for man, because without it he would not fully fulfill his being. Finally, a characterization of the population is made, establishing their perception of coexistence and being able to arrive at the construction and implementation of the "Design of the coexistence proposal" that took into account the four pillars of learning pointed out by Delors (1996): knowing how to know , knowing how to do, knowing how to be, knowing how to live together; The present strategy had human development as its central axis from the conception of Saint Thomas Aquinas as well as from that of Paulo Freire, and identified the educable subject as a multidimensional student, for which reason it is not only necessary to work on an academic curriculum that privilege cognitive content, but to develop other skills that enable the empowerment of your being as a person: with values, emotions and a pre-eminent sense of otherness, of otherness,Magíster en Educaciónhttp://www.ustadistancia.edu.co/?page_id=3956Maestrí
Equity in unequal deductions : implications of income tax rules in Ghana and Nigeria
No full textIn many African countries, the amount of personal deduction for income tax purposes increases with the taxpayer's income. At first glance, this appears to give larger tax breaks to the rich than to the poor. On closer examination, this notion turns out to be false. As this paper shows, each tax system with"income dependent tax deductions"(IDTDs) is fully equivalent to a particular conventional progressive tax system with standard deductions. One implication for comparative tax research is that the tax schedule of a country that uses IDTDs should not be compared directly with a conventional tax schedule in another country. Existing cross-country work on tax deductions and marginal tax rates generally fails to recognize that IDTDs invalidate a straightforward comparison. To make the two systems comparable, a transformation like the one suggested in this paper is needed.Public Sector Economics&Finance,Environmental Economics&Policies,Tax Policy and Administration,Taxation&Subsidies,Governance Indicators
Efficient debt reduction
No full textIt is now widely acknowledged that under certain circumstances debt reduction can improve the welfare of both creditors and debtors. Meaningful debt reduction requires an appropriate institutional setting to overcome collective action problems. In the domestic economy, bankruptcy laws provide the framework for organizing the collective interests of the creditors when a debtor is distressed. No such institutional framework exists in the international setting. This paper recommends"concerted debt restructuring,"based on below market interest rates, rather than"voluntary"debt reduction. With concerted relief, all banks would participate jointly on a fairly equal basis. The existing debt would be rescheduled, with the rates based on various indicators of ability to pay. The interest payments could be made more secure by various forms of credit enhancement. This kind of interest rate reduction could be easily managed in the context of an international debt facility. Whatever the approch, meaningful debt reduction will require the active participation of the international community.Strategic Debt Management,Banks&Banking Reform,Financial Intermediation,Housing Finance,Economic Theory&Research
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