Novel applications of spectroscopy to characterize soil variation

This thesis embodies a collection of novel studies related to the use of multivariate information provided by spectroscopic tools such as Visible and Near Infrared (Vis-NIR) spectrometers to represent soil variation. The general structure is organized following the increasing levels of soil complexity, starting from the characterization of soil aggregates and the identification of soil colloids, to the recognition of soil horizons and their boundaries in the soil profile, to finally the depiction of soil type’s distribution in the landscape. Briefly, Chapter 1 is written as a rationale, emphasising the need for up-to-date methodologies for making effective use of the increasing amount of soil information produced worldwide. Chapter 2 presents the development of a new methodology for the measure of soil aggregate stability and the further use of spectroscopic information to predict its values. Chapter 3 gives examples of the use of Vis-NIR spectral libraries for the prediction of soil properties. Chapter 4 presents the development of a new method for the identification of soil horizons and their boundaries using fuzzy clustering of Vis-NIR spectra. Chapter 5 expands into a new way of measuring the diversity of soils into the landscape, introducing two new indices for measuring soil diversity or “Functional Pedodiversity” inspired in previous studies in Functional Ecology. Finally Chapter 6 discusses the main findings of this thesis and foresees issues, challenges and opportunities in the area of spectroscopy and multivariate soil data analysis

The Role of Justice in Colombia’s Renewable Energy Transition: Wind Energy Development in Wayúu Territory

Amidst the defining issue of our time – climate change – the world faces an imperative to shift from fossil fuels to renewable energy, aligning with the 2015 Paris Agreement goals. This global focus on low-carbon energy infrastructure has brought forth local socio-environmental conflicts, and at the heart of this transition lies La Guajira, a peninsula in northern Colombia, home to the indigenous Wayúu people and abundant wind energy resources. This research delves into the critical role of energy justice as large-scale wind energy projects expand in La Guajira. By examining the struggles faced by the Wayúu people provoked by wind energy development in their ancestral territory, the study integrates the energy justice framework with qualitative data collected through fieldwork in Colombia. The investigation focuses on perceived injustices by Wayúu communities during indigenous consultation processes, examined in relation to procedural, distributional, and recognition justice. The research approach includes 22 semi-structured interviews with stakeholders, including community leaders, grassroots organizations, government authorities, industry representatives, and scholars; it also draws from participant observations, site visits, and policy analysis, all gathered within a collaborative research process with Wayúu female leaders. By amplifying the voices of the Wayúu people and acknowledging historical imbalances, this research aims to contribute to a more inclusive and sustainable energy transition policy in Colombia and beyond. The findings shed light on the multiple injustices endured by the Wayúu community, including the lack of recognition of their culture, biased consultation procedures, and at times reinforcing broader structural inequalities. The study advocates for restorative justice and an intersectional approach to inform energy policies and indigenous consultation laws. Achieving a just energy transition in La Guajira is paramount, not only to reconcile historical resistance against the fossil fuel industry but also to align with the urgent goals of combatting climate change. Ignoring energy justice concerns risks perpetuating grave injustices, threatening indigenous communities’ cultural integrity, livelihood, and environment

Assessment of experimental optical techniques for characterizing heat transfer using numerical simulations

This manuscript addresses the application of numerical simulations for assessing the error in the measurement of the bulk temperature along the laser beam of a 3D flow using a 2D Moiré deflectometry analysis. To analyze the effect of different flow parameters on the error, a 3D computational model of an experimental system was developed. The simulated domain represents the well-known solution of the backward facing step in a rectangular channel but includes a hot-plate at the bottom of the step to enhance the heat transfer effects. The geometry resembles that found in a general heat exchanger. The difference between the computed bulk temperature of the flow and the average temperature obtained via the 2D Moiré is analytically evaluated for various assumed general temperature profiles; the numerically computed profiles of temperature indicates that the error decreases with the channel aspect ratio. The use of CFD enables the determination of the flow topology and thus an evaluation of the 3D flow behavior that will cause the measurement error. A parametric study was performed for different flow conditions, namely, the aspect ratio of the channel, the inflow conditions (flow velocity or Reynolds number), and the temperature of the hot wall. The results indicate that the Moiré technique is suitable for evaluating the bulk temperature in typical heat exchange devices and flow conditions

Some Results of the Educational Experiment APIS (Cervantes Mission on Board ISS)

Some results of the analysis of the pictures taken along the performance of the Análisis de Propiedades Inerciales de Sólidos, Analysis of the Inertia Properties of Solid Bodies (APIS) experiment carried out in the Cervantes mission on board ISS, are presented. APIS was an educational experiment devoted to take advantage of the unique conditions of absence of relative gravity forces of a space platform such as ISS, to show some of the characteristics of the free rotational motion of a solid body, which are impossible to carry out on earth. This field of experimental research has application to aerospace engineering science (e.g. attitude control of spacecrafts), to astrophysical sciences (e.g. state of rotation and tumbling motions of asteroids) and to engineering education. To avoid the effect of the ambient atmosphere loads on the motion, the test body is placed inside a sphere, which reduces the effect of the aerodynamic forces to just friction. The drastic reduction of the effect of the surrounding air during the short duration of the experimental sequences allows us to compare the actual motion with the known solutions for the solid body rotation in vacuum. In this paper, some selected, relevant sequences of the sphere enclosing a body with a nominal cylindrical inertia tensor, put into rotation by the astronaut, are shown; the main problems to extract the information concerning the characteristic parameters of the motion are outlined, and some of the results obtained concerning the motion of the test probe are included, which show what seems to be a curious and unexpected solution of the Euler equations for the solid body rotation in vacuum, without energy dissipation, when the angular momentum is almost perpendicular to the axisymmetry axis

Aggressive Surveillance Is Needed to Detect Endoleaks and Junctional Separation between Device Components after Zenith Fenestrated Aortic Reconstruction

Background Junctional separation and resulting type IIIa endoleak is a well-known problem after EVAR (endovascular aneurysm repair). This complication results in sac pressurization, enlargement, and eventual rupture. In this manuscript, we review the incidence of this late finding in our experience with the Cook Zenith fenestrated endoprosthesis (ZFEN, Bloomington, IN). Methods A retrospective review was performed of a prospectively maintained institutional ZFEN fenestrated EVAR database capturing all ZFENs implanted at a large-volume, academic hospital system. Patients who experienced junctional separation between the fenestrated main body and distal bifurcated graft (with or without type IIIa endoleak) at any time after initial endoprosthesis implantation were subject to further evaluation of imaging and medical records to abstract clinical courses. Results In 110 ZFENs implanted from October 2012 to December 2017 followed for a mean of 1.5 years, we observed a 4.5% and 2.7% incidence of clinically significant junctional separation and type IIIa endoleak, respectively. Junctional separation was directly related to concurrent type Ib endoleak in all 5 patients. Three patients presented with sac enlargement. One patient did not demonstrate any evidence of clinically significant endoleak and had a decreasing sac size during follow-up imaging. The mean time to diagnosis of modular separation in these patients was 40 months. Junctional separation was captured in surveillance in 2 patients and reintervened upon before manifestation of endoleak. However, the remaining 3 patients completed modular separation resulting in rupture and emergent intervention in 2 and an aortic-related mortality in the other. Conclusions Junctional separation between the fenestrated main and distal bifurcated body with the potential for type IIIa endoleak is an established complication associated with the ZFEN platform. Therefore, we advocate for maximizing aortic overlap during the index procedure followed by aggressive surveillance and treatment of stent overlap loss captured on imaging

Grapevine virus diseases: economic impact and current advances in viral prospection and management.

Grapevine (Vitis spp.) is a major vegetative propagated fruit crop with high socioeconomic importance worldwide. It is susceptible to several graft-transmitted agents that cause several diseases and substantial crop losses, reducing fruit quality and plant vigor, and shorten the longevity of vines. ] The vegetative propagation and frequent exchanges of propagative material among countries contribute to spread these pathogens, favoring the emergence of complex diseases. Its perennial life cycle further accelerates the mixing and introduction of several viral agents into a single plant. Currently, approximately 65 viruses belonging to different families have been reported infecting grapevines, but not all cause economically relevant diseases. The grapevine leafroll, rugose wood complex, leaf degeneration and fleck diseases are the four main disorders having worldwide economic importance. In addition, new viral species and strains have been identified and associated with economically important constraints to grape production. In Brazilian vineyards, eighteen viruses, three viroids and two virus-like diseases had already their occurrence reported and were molecularly characterized. Here, we review the current knowledge of these viruses, report advances in their diagnosis and prospection of new species, and give indications about the management of the associated grapevine diseases. Index terms: Vegetative propagation, plant viruses, crop losses, berry quality, next-generation sequencing. VIROSES EM VIDEIRAS: IMPACTO ECONÔMICO E RECENTES AVANÇOS NA PROSPECÇÃO DE VÍRUS E MANEJO DAS DOENÇAS DE ORIGEM VIRAL A videira (Vitis spp.) é propagada vegetativamente e considerada uma das principais culturas frutíferas por sua importância socioeconômica mundial. Ela é suscetível a vários agentes transmitidos por meio da enxertia, os quais causam diversas doenças e significativas perdas na produtividade e produção, redução na qualidade dos frutos, no vigor da planta e na longevidade dos vinhedos. A propagação vegetativa e o frequente intercâmbio de material propagativo entre países contribuem para a disseminação destes patógenos, favorecendo a emergência de doenças complexas. Seu ciclo de vida perene acelera ainda mais a mistura e a introdução de vários agentes virais em uma mesma planta. Atualmente, aproximadamente 65 vírus pertencentes a diferentes famílias foram reportados infectando videiras, embora nem todos causem doenças economicamente relevantes. As viroses do enrolamento da folha, complexo do lenho rugoso, degenerescência e mancha-das-nervuras da videira são as quatro principais desordens que têm importância econômica mundial. Além disso, novas espécies e estirpes virais foram identificadas e associadas a limitações economicamente importantes para a produção de uvas. Em vinhedos brasileiros, dezoito espécies virais, três viroides e duas doenças semelhantes a viroses já tiveram sua ocorrência reportada e foram molecularmente caracterizados. Aqui, nós revisamos o conhecimento atual dessas viroses, os recentes avanços na diagnose e prospecção viral, e fornecemos recomentações sobre o manejo das viroses da videira. Termos para indexação: Propagação vegetativa, vírus de plantas, redução da produtividade e produção, qualidade das bagas, sequenciamento de nova geração