Tesis de Gregorio E. Durán para obtener el título de Doctor en Medicina y Cirugía de la Facultad de Medicina en la Universidad Nacional de Colombia en 1892. A lo largo del documento Durán presenta una reseña histórica sobre la enfermedad, así como las principales características de su etiología y patogenia. De igual forma, el autor describe las complicaciones y elementos que influyen en el desarrollo de la enfermedad, y termina su exposición comentando sobre el tratamiento regular, el de injertos epidérmicos y observaciones respecto a la evolución de las úlceras varicosas en tres pacientes.

Tesis para obtener el título de doctor en Medicina y Cirugía de la Facultad de Medicina en la Universidad Nacional de Colombia 1891. A lo largo del documento, Eduardo Uribe R. estudia la pelagra, enfermedad producida por la falta de vitamina B3 en la alimentación. Finalmente, se mencionan los nombres comunes de la enfermedad, su historia, etiología, anatomía patológica, diagnóstico diferencial, lesiones amatomo – patológicas, y casos registrados de la enfermedad en el país, que por el mal diagnóstico de los médicos, se han confundido con otros padecimientos.

Tesis escrita por Manuel Lobo para optar por el título de doctor en medicina de la Universidad Nacional de Colombia en 1891. A lo largo de la investigación, Lobo se propone señalar las diferencias y las pruebas diagnósticas utilizadas para identificar la neumonía fibrinosa y la neumonía catarral en pacientes adultos.

Tesis de José Manuel Vásquez para obtener el título de doctor en Medicina y Cirugía de la Facultad de Medicina en la Universidad Nacional de Colombia en 1892. A lo largo del documento Vásquez analiza varios aspectos relacionados al procedimiento quirúrgico que investiga en esta oportunidad: su historia, la anatomía de la uretra, indicaciones y contraindicaciones, manual operatorio y complicaciones que podrían presentarse durante la práctica de una uretrotomía. Finalmente, se presentan estudios de caso y breves conclusiones que surgen del análisis sobre los mismos.

Tesis de Aristides Lores para obtener el título de doctor en Medicina y Cirugía de la Facultad de Medicina en la Universidad Nacional de Colombia en 1892. A lo largo del documento Lores estudia la peritonitis tuberculosa, complicación producida por inflamación del intestino. El autor define la enfermedad, su historia, etiología, causas predisponentes, causas determinantes, sintomatología, y otras particularidades como la enquistada o ulcerosa de la misma, anatomía patológica, marcha de las formas crónicas, diagnóstico, tratamiento y tratamiento quirúrgico. Finalmente, Lores presenta observaciones sobre la autopsia realizada a tres personas que murieron de esa enfermedad.

A technological and environmental alternative has been studied for about a decade to reduce the consumption of coal. It consists of substitute one part of the coal by biomass (neutral generated of CO2) in a co-_ring process. The co-_ring process consists of the controlled combustion of two or more fuels in the same burner. According to research performed in the US and Europe this process has economic and technical viability. And depending on the characteristics of the fuel, this process can contribute reducing the greenhouse gases (GHG). This thesis presents a methodological proposal to analyze and evaluate a thermoelectric power plant from the exergoenviromental point of view, operating in co-_ring process and using coal and biomass. The boundary of the problem is composed by the power plant and the technological paths to obtain and manipulate the fuels. Exergy is used in the thermodynamic analysis and the life cycle assessment method is proposed to quantify the environmental impact. The climate change category was used following the global warming potential index. Two scenarios were evaluated: scenario A corresponds to the power plant operating with 100% coal and scenario B corresponds to the power plant operating in co-_ring with 90% of coal and 10% of biomass. The technological route used for the coal is established between the southern mineral region of the state of Santa Catarina and the Jorge Lacerda thermoelectric power plant complex, which is located at Capivari de Baixo. The information utilized for the biomass path was obtained from the research performed in the thermoelectric power plant complex. The purpose of this task was to use the biomass from the rice farms as fuel. The analysis showed that the power plant is largely responsible for exergy destruction. Moreover it has the largest generated impact associated with the analyzed category. From these results, an exergoenvironmental analysis for the representative thermodynamic cycle was performed. The results showed that the boiler constitutes the equipment with the largest potential of improvement.  Finally, an exergoenvironmental global index was proposed to compare the exergoenvironmental impact of the thermoelectric generation process for both scenarios, which were compared with Carnot cycle scenario. The exergoenvironmental global index showed that 11% improvement is possible for the scenario B when compared with scenario A without taking in account the biomass microbial decomposition and up to the 35% when the decomposition was considered.

Trabajo de grado de Antonio Gómez para obtener el título de Doctor y Cirujano de la Universidad Nacional, en 1922. En la primera parte se hace una recopilación sobre las investigaciones en torno al sarampión y lo que a la fecha se sabía de la enfermedad. En la segunda, se habla de la epidemia de sarampión en Bogotá de 1914 y la forma como fue fue atendida por parte del personal médico de la ciudad.

Abstract: The synthesis of nanostructures has attracted much interest due to their advanced properties compared to their bulk material. Zinc Oxide (ZnO) has gained substantial interest in the research community due to its large exciton binding energy (60 meV). ZnO is a semiconductor with several favorable properties like a good transparency in the visible region, and a wide band gap of 3.37 eV. Those properties are already used in many emerging applications as chemical sensors, nano laser, and transistors. Due to its wurtzite crystal structure ZnO readily grows to elongated nanoparticles such as nanorods or nanowires. Elongated nanostructures are promising due to precise electron transport in one direction. Special attention has been devoted to the realization of transparent conductive oxides (TCOs) for optoelectronic devices such as solar cells and displays. The first part of this thesis is dedicated to the comparison of the synthesis of ZnO nanorods in a three-neck flask to solvothermal method. In order to investigate the effects of various reaction parameters on the structural and optical properties in the solvothermal method, different temperatures, volumes of solvent and reaction time were selected. The second part addresses the tailoring of the microstructure and electrical properties of ZnO nanorods modified with aluminum and indium, respectively. Finally, doped ZnO nanorods thin films prepared on glass substrate by drop casting method were investigated. This thesis provides first experimental work for transparent conductive zinc oxide prepared by solvothermal synthesis and highlights possibilities and boundaries for introduction of dopants in ZnO nanorods. Resumen: La síntesis de nanoestructuras ha atraído mucho interés debido a sus excelentes propiedades en comparación con su material a granel. El óxido de zinc (ZnO) ha ganado un interés sustancial en la comunidad de investigación debido a su gran energía de ligadura (60 meV). ZnO es un semiconductor con varias propiedades favorables, así como una buena transparencia en la región visible, y una amplia brecha de banda de 3,37 eV. Esas propiedades ya se utilizan en muchas aplicaciones emergentes como sensores químicos, nano láser y transistores. Debido a su estructura de cristal de wurtzita, ZnO se desarrolla fácilmente a nanopartículas alargadas como nanorods o nanocables. Las nanoestructuras alargadas son prometedoras debido al transporte preciso de electrones en una dirección. Se ha dedicado especial atención a la realización de óxidos conductores transparentes (TCO) para dispositivos optoelectrónicos como células solares y pantallas. La primera parte de esta tesis está dedicada a la comparación de la síntesis de nanorods de ZnO en un matraz de tres bocas versus un método solvotermal. Con el fin de investigar los efectos de diversos parámetros de reacción sobre las propiedades estructurales y ópticas en el método solvotermal, se seleccionaron diferentes temperaturas, volúmenes de disolvente y tiempo de reacción. La segunda parte aborda la adaptación de la microestructura y las propiedades eléctricas de los nanorods de ZnO modificadas con aluminio e indio, respectivamente. Finalmente, se investigaron las películas finas de nanorods modificadas y preparadas sobre sustrato de vidrio mediante el método de moldeo a gotas. Esta tesis proporciona el primer trabajo experimental para óxido de zinc como conductor transparente preparado por síntesis solvotérmica y resalta las posibilidades y los límites para la introducción de dopantes en nanorods de ZnO.

The need of understanding the relationship between the physical habitat and ecology in the fluvial systems has become a major issue due to an increasing environmental conciousness but also because of the normativity which demand the achievement of the good status of the water bodies and its ecosystems. Exactly this requirement is prescribed by the European Water Framework Directive (WFD) which have included the hydromorphology as an important aspect of evaluation due to the influence that it has on the ecology of a river system. The hydromorphology gets relevance because it study the system as a whole, involving the interactions between ecology, hydrology and fluvial geomorphology. As a response to the WFD each country of the European Union has developed a method for guaranteeing the compliance of the normativity. Elements of such methods and of international literature are collected for the development of a methodology that fulfill the gaps of the current Colombian water normativity and support the decision making in the environmental planning and impact assessment. This guide for the river morphological restoration in Colombia is a complete hydromorphological analysis of a selected river which main purpose is to make an approach to the general aspects of the river in the macro scale, followed by an assessment in the meso scale in which the river is segmented, classified and the hydromorphological conditions are scored; finally, a simulation is performed for a critical reach, called in this work the “bottle neck” reach. The simulation consists in a hydrodynamics model (or hydromorphodynamics model as optional), its results of depth, velocity and substrate in combination with the preferences of a fish indicator species, are computed in the software CASiMiR and give the habitat suitability in the study area for the simulated conditions. The application of such methodology is applied in a mountainous river reach downstream the Punt da Gall dam in Switzerland for which the hydromorphological aspects in the macro and meso scale are assessed and in the micro scale the habitat distribution of fish indicator species are calculated. The present work is an attempt to apply the habitat simulation as a tool for determining hydromorphological quality, for river restoration activities and for determining minimum habitat conditions when the discharge is regulated. Future investigations include the application in a Colombian river for which the collection of biological data still is a challenge.

This research is focused on obtaining an important reduction in greenhouse gas (GHG) emissions resulting from the use of fossil fuels by increasing the efficiency of pre-combustion carbon capture. It examines a new, low-risk, approach that uses conventional water gas shift reactors and acid gas removal technology in a unusual arrangement, within an Integrated Gasification Combined Cycle power plant (IGCC). Timmins (2010) proposed a flowsheet of this nature and it is this flowsheet that is used as the starting point for this research project. Process simulation in UniSim Design R390 is conducted  to validate the viability of such  a flowsheet and to investigate optimal plant configuration. The modelling output is compared to US DOE baseline studies for competing technologies (2010).The physical solvent, Selexol, is used for cardon dioxide (CO2) absorption as recommended by researchers as the most energy efficient amongst the range of physical and chemical solvents investigated. There are mainly two thermodynamic models required to meet all of the needs of this complex process. Most of the process is modelled with the Peng-Robinson equation of state but the Selexol absorber and desorber is modelled using the non-random-two-liquid model  (NRTL) for the liquid phase and the ideal gas law for the vapour phase. A beseline flowsheet model is successfully modelled that could be attached to an IGCC plant to enable it to continue producing electric power whilst capturing 90% of the carbon derived from the fuel. The model is used for process development, and for energy efficiency evaluation. Every major item of capital equipment has been included, modelled and sized to produce a cost analysis and additionallly, the model output was used for a preliminary life cycle analysis (LCA). From the results produced in this study, the proposed process appears to be a feasible, energy-efficient, alternative technology for incorporating carbon capture within an IGCC flowsheet.