<p dir="ltr">Since the 1990s, the use of commercial off-the-shelf (COTS) microelectronics in extreme applications – such as military, aerospace, and space missions – has grown significantly. This shift was initially driven by cost savings and rapid technological advancements, a trend that accelerated in the 2000s due to increasing demand for electronics in harsh environments. Over the past decade, industries such as automotive (e.g., autonomous vehicles) and space (e.g., low-earth orbit/LEO satellite constellations) have also adopted COTS electronics. However, reliability concerns persist, especially in complex chip-package-board interactions under extreme conditions. Operating environments, which include high radiation, temperature fluctuations, and moisture, present significant challenges. New failure modes have emerged, such as increased leakage current, mass loss from volatile components, and corrosion.</p><p dir="ltr">This thesis offers a system-level, physics-based approach to reliability modeling. It examines the combined impact of heat, moisture, charge, and radiation transport (e.g., high energy protons) in integrated circuits (ICs), packaging, and boards. We provide a detailed analysis of ion transport and charge injection in a system involving epoxy polymers and metal contacts (typical of packaging) under extreme dry and wet conditions. Furthermore, this thesis explores the reliability of plastic packages in radiation-intense and space environments. A generalized model for predicting corrosion failures in self-heated ICs is developed, considering global environmental variations such as temperature and humidity. The work also proposes real-time age monitoring of COTS components for critical high-security applications. In summary, this thesis introduces innovative reliability strategies for modern microelectronic systems, providing a comprehensive general framework to predict failures in harsh environments.</p>

Flooding effects mineral composition of pasture grasses, but little is known concerning effects on mineral metabolism and fiber digestibility in animals. Experiments were conducted to investigate effects of flooding and Al-nitrilo-triacetate (Al-NTA) on growth, chemical composition and digestibility of annual ryegrass (Lolium multiflorum, L.). Ryegrass was grown in a greenhouse experiment on Bucks silt loam soil with two soil moisture levels (flooding and 80% field capacity) and two Al rates (0 and 135 mg/kg) as Al-NTA. Flooding increased Al, Fe, Cu, Ca and fiber and decreased dry matter yield, Mg, K and Zn concentrations. Treatment with 135 mg/kg Al had no effect on Al in plants, but decreased Ca and P concentrations. Two digestion trials were conducted with meadow voles (Microtus pennsylvanicus) fed forage harvested from the greenhouse experiment. Voles were housed in stainless steel metabolism cages for total collections of feed and feces. A 2-day preliminary, during which voles were fed 100% ryegrass, preceded a 3-day collection period. At the end of the collection period, a blood sample was taken from the animals. Forage grown under flooding increased apparent absorption of Al, and Ca concentration in urine samples. Apparent absorption of Mg and serum Mg were decreased, and dry matter digestibility tended to decrease. Grazing forages produced under flooded conditions would increase potential for outbreaks of grass tetany in animals due to reduced Mg intake and absorption. Altered Mg and Ca metabolism appeared related to Al ingestion. Lowered animal performance could result from reduced DM digestibility. / Master of Science

Concrete is a popular construction material for bridges, due to its high durability and energy efficiency. An important concern for concrete bridges is the possible occurrence of chloride- induced corrosion in prestressing strands and reinforcing bars, which may substantially impact the service life of such structures. Chloride- induced corrosion is a complicated electrochemical process which is affected by heat transfer, moisture flow and transport of chemical species through the concrete pore network. Reliable and robust analytical tools are required to allow multi-physics simulations of steel corrosion. This study has developed a nonlinear finite element analysis program, called VT-MultiPhys, to enable multi-physics simulations, including analyses of chloride-induced corrosion. The program includes constitutive laws, element formulations and global solution schemes to allow the analysis of steady-state (static) and time-dependent (dynamic) problems, involving multiple, coupled processes such as mechanical deformation, heat transfer, mass flow and chemical reactions combined with advective/diffusive transport of the various species. Special analysis schemes, based on the streamline-upwind Petrov-Galerkin (SUPG) method, have also been implemented to address the spatial instabilities which characterize analyses of advection-dominated transport. The finite element modeling scheme, constitutive laws and boundary conditions for analysis of chloride-induced corrosion are described in detail. The constitutive laws can be combined with inelastic material models to capture the damage (e.g., cracking) due to chloride-induced corrosion. A set of verification analyses is presented, to demonstrate the capabilities of VT-MultiPhys to conduct different types of simulations and reproduce the closed-form analytical solutions of simple cases. Validation analyses for heat conduction, moisture flow and chloride transport, using data from experimental tests in the literature, are also presented. / Master of Science / The deterioration of concrete structures and infrastructures due to the chloride-induced corrosion in prestressing strands and reinforcing bars may substantially impact the service life of such structures. Chloride-induced corrosion is a complicated electrochemical process which is initiated and proceeds due to the chloride attacks at the surfaces of concrete structures and ends in the volume expansion, cracking and spalling of concrete. Due to the lack of comprehensive modeling tool, which can simultaneously comprise the influential factors in chloride-induced corrosion, the realistic estimation of the service life of reinforced concrete structures is still challenging. Reliable and robust analytical tools are required to allow multi-physics simulations of steel corrosion. This study has developed a comprehensive finite element analysis program, called VT-MultiPhys, for calculating and monitoring the contribution of chloride ions to chloride-induced corrosion during service life of concrete structures. The present analysis program enables modeling of the coupled physical process including heat transfer, moisture flow and transport of chemical species through the concrete pore network. Also, by modeling the influence of flexural cracks on chloride transport in concrete, the analysis program is able to predict the rate of steel corrosion in cracked concrete structures. A set of verification analyses is presented, to demonstrate the capabilities of VT-MultiPhys to conduct different types of simulations of heat conduction, moisture flow and chloride transport and the comparison is found to be satisfactory. The element formulations and solution algorithms in VT-MultiPhys also allow the investigation of other long-term deterioration mechanisms, such as carbonation-induced corrosion, alkali-silika reaction (ASR) and sulfate attack. The present contribution will hopefully enable and facilitate future research in these topics, through the formulation and implementation of proper constitutive laws and chemical reaction equations.

A model to predict the thermo-hygro-mechanical behaviour of wood is introduced. The description of the transport processes of moisture and heat are combined with a model for the mechanical response. Moisture transport is represented by a two-phase multi-FICKian approach, considering bound water and water vapour. For the mechanical response, a moisture- and temperature-dependent, orthotropic, elastic material formulation is used. The theoretical basis of the model and the numerical implementation of the monolithic solution into a Finite Element framework are discussed as well as its verification and validation. With this model at hand, arbitrary wooden structures can be simulated in a transient manner subjected to climatic and mechanical loads. In the contribution, the approach is applied to the analysis of a panel painting by L. CRANACH the Elder.

A preliminary experiment was conducted to determine the effects of salinity and moisture stress on the pathogenicity of root-knot nematodes (RKN) in turfgrass plants. The results indicated that RKN infection adversely affected both visual and functional parameters of bentgrass. Salinity and moisture stress further exaggerated the damage caused by RKN. Under well-watered conditions, the effects of SWC and RKN infection on bentgrass plants were studied. Applications of Swe at 0.5 liter ha⁻¹ and 1.0 liter ha⁻¹ effectively enhanced bentgrass growth under both RKN-free and RKN-infected condition. It was shown that RKN caused less damage to SWC-treated plants than to non-treated plants. In addition, a soil drench of 0.5 liter ha⁻¹ and 1.0 liter ha⁻¹ at 10 day intervals was required to enhance bentgrass growth under RKN-free and RKN-infected conditions, respectively. The effects of seven SWC treatments on the growth of nematode-free and RKN infected bentgrass plants were tested under three irrigation regimes. Rooting and leaf moisture parameters, quality and clipping yield were all improved to some degree by SWC applications. High dosage SWC treatments, applied as a soil drench at one liter ha⁻¹ every 10 days, were most effective in improving plant growth. Application of SWC was more beneficial to RKN-infected plants than RKN-free plants, and to abiotically stressed plants than to abiotic stress-free plants. In a separate study, seaweed application was also shown to enhance both top growth and root growth of lance nematode (Hoplolaimus galeatus) or RKN infected bentgrass grown under drought or salinity stress condition. With SWC application, almost all of the symptoms caused by nematode infection and the abiotic stress were partially overcome. In addition, root development, leaf water status and clipping yield were all improved. It was apparent that soil drench SWC treatments were more effective in enhancing bentgrass growth than foliar Swc treatments. Application of SWC slightly reduced the number of nematodes per unit of fresh root (for RKN) and per unit weight of soil (for lance nematodes). Protein extracted from SWC-treated or non-treated ryegrass plants under different stress conditions indicated that SWC altered plant protein synthesis, possibly by inducing selective gene expressions. / Ph. D.

Freshwater is a finite resource that is rapidly becoming more scrutinized in agricultural consumption. Specialty crop producers, especially ornamental crop producers, must continually improve production sustainability, with regards to water resource management, in order to continue to stay economically viable. Soilless substrates were initially developed to have increased porosity and relatively low water holding capacity to ensure container crops would not remain overhydrated after irrigations or rain events. As a result, substrates were selected that are now considered to be in efficient in regards to water resource management. Therefore, to provide growers with additional means to improve production sustainability, soilless substrate hydrology needs be innovated to provide increased water availability while continuing to provide ample air filled porosity to ensure productive and efficient water interactions. Historically, soilless substrates have been characterized using "static" physical properties (i.e. maximum water holding capacity and minimum air-filled porosity). The research herein involves integrating dynamic soilless substrate hydraulic properties to understand how substrate hydrology can be manipulated to design sustainable substrates. This task involved adapting new technologies to analyze hydrological properties of peat and pine bark substrates by employing evaporative moisture characteristic measurements, which were originally designed for mineral soils, for soilless substrate analyses. Utilizing these evaporative measurements provide more accurate measures of substrate water potentials between -10 and -800 hPa than traditional pressure plate measurements. Soilless substrates were engineered, utilizing only three common substrate components [stabilized pine bark (Pinus taedea L.), Sphagnum peatmoss, and coconut coir fiber], via particle fractionation and fibrous additions. The engineering process yielded substrates with increased unsaturated hydraulic conductivity, pore connectivity, and more uniform pore size distributions. These substrates were tested in a greenhouse with irrigation systems designed to hold substrates at (-100 to -300 hPa) or approaching (-50 to -100 hPa) water potentials associated with drought stress. Substrate-water dynamics were monitored, as were plant morphology and drought stress indicators. It was determined that increased substrate unsaturated hydraulic conductivity within the production water potentials, allowed for increased crop growth, reduction in drought stress indicators, while producing marketable plants. Furthermore, individual plants were produced using as low as 5.3 L per plant. Increased production range substrate hydraulic conductivity was able to maintain necessary levels of air-filled porosity due to reduced irrigation volumes, while providing water for plants when needed. The substrates were able to conduct water from throughout the container volume to the plant roots for uptake when roots reduced substrate water potential. Furthermore, increased substrate hydraulic conductivity allowed plants within the substrate to continue absorbing water at much lower water potentials than those in unaltered (control) pine bark. Finally, HYDRUS models were utilized to simulate water flux through containerized substrates. These models allowed for better understanding of how individual hydraulic properties influence substrate water flux, and provided insight towards proportions of inaccessible pores, which do not maintain sufficient levels of available water. With the models, researchers will be able to simulate new substrates, and utilize model predictions to provide insight toward new substrates prior to implementing production tests. It has been determined, that increasing substrate hydraulic conductivity, which can be done with just commonly used components, water requirements for production can be reduced, to produce crops with minimal wasted water resources. Concluding, that re-engineering substrate hydrology can ameliorate production sustainability and decrease environmental impact. / Ph. D. / The world is rapidly approaching a time when water will become a limited resource, not only for agriculture, but all daily uses. As a result specialty crop production must continue to increase sustainability in order to continue to thrive. One area where growers and researchers believe environmental stewardship can be increased is through designing more resource efficient soilless substrates. Soilless substrates (potting media) are utilized world-wide by container crop producers as a rooting medium for specialty crops. These substrates were developed to be very forgiving for growers. By that, growers could apply excess water through irrigation or precipitations and these substrates were designed to readily drain excess water. This provides an opportunity to create more water efficient substrates to help reduce water consumption by container nurseries. The processes involving water-air-substrate interactions within the container are not well understood. As a result, my research involves measuring, manipulating, maintaining, and modeling substrate hydrology in an effort to design substrates that will conserve water in container production. I incorporated new technology used in Soil Science to measure hydraulic properties of soilless substrates through the evaporative method. I then understood how growers and allied suppliers can easily modify these substrate hydraulic properties. Next, I researched how these manipulated hydraulic properties would influence plant growth and vitality, by maintaining drought level irrigation levels over multiple crops. Finally, I modeled substrate hydraulic properties to better understand water movement through a container. Through the research herein, I was able to determine that substrate hydrology can be easily modified to provide container crops with more easily accessed water, while still keeping sufficient air-space for plant growth. Increasing unsaturated hydraulic conductivity in soilless substrates, allows ornamental crops to be held at lower water regimes moisture levels traditionally considered to be drought levels. Utilizing the HYDRUS model, I was able to determine how to develop future substrate models that will accurately simulate real-world outcomes, providing researchers with another tool to quickly predict impacts of newly developed (or still in development) soilless substrates on water status in container production.

Der Verbrauch von Heizenergie in Bestandsgebäuden stellt einen großen Anteil am gesamten Energieverbrauch in Deutschland dar und trägt deshalb maßgeblich zur Produktion von klimaschädlichem CO2 bei. Um den Klimawandel aufzuhalten und einen substanziellen Beitrag zum Klimaschutz zu leisten, muss deshalb der Heizenergieverbrauch weiter reduziert werden. Dies geschieht am effektivsten durch den Erhalt und die energetische Sanierung von Gebäuden. Durch diese Maßnahmen werden nicht nur die Heizkosten gesenkt, sondern auch der Wohnkomfort sowie die Wertigkeit der Gebäude erhöht.:1 Einleitung 1 1.1 (Innen-)Dämmung von Gebäuden 1 1.2 An wen richten sich diese Leitfäden? 1 2 Bauwerksanalyse und Feuchte in Gebäuden 2 3 Welche Arten von Wänden werden betrachtet? 2 4 Planungsphasen 3 5 Vorbereitung und Durchführung der Vor-Ort-Untersuchung 3 5.1 Informationen über das Gebäude 3 5.2 Planung 4 5.3 Durchführung 5 6 Hauptquellen von Feuchte in Fassaden 8 6.1 Eindringen von Schlagregen in Fassaden, Fassadenelemente oder -öffnungen 9 6.2 Aufsteigende Feuchte 12 6.3 Hygroskopische Feuchte und hygroskopische Salze 13 6.4 Wärmebrücken (Kondensation, Schimmel) 15 7 Analyse der Ergebnisse 16 7.1 Durch Feuchte verursachte Schadensbilder 16 7.2 Fassadenmaterialien, die Feuchteprobleme beeinflussen oder verschärfen 19 8 Messmethoden 21 8.1 Messen des Wassergehalts 22 8.2 Messen der kapillaren Wasseraufnahme der Fassade 25 8.3 Messen des Raumklimas 27 8.4 Salzmessungen 27 8.5 Weitere Messungen 28 9 Literatur und Links 29 Anhang 30 A 1 Beispiele für typische, feuchtebezogene Schadensbilder 30 Gruppe 1 Typische feuchtebedingte Schadensbilder 30 Gruppe 2 Schäden, die Feuchte in Wänden beeinflussen können 41 Gruppe 3 Fassadenelemente, die Feuchteprobleme beeinflussen können 50 Gruppe 4 Fassadenmaterialien, die Feuchteprobleme beeinflussen 55 A 2 Hinweise zur Anwendung der Messmethoden 61 A 3 Ausrüstung und Vorbereitung einer Begehung 66 A 4 Glossar 66 A 5 Ablaufschema 68

The consumption of heating energy in existing buildings represents a large share of total energy consumption and therefore contributes significantly to the production of climate-damaging CO2. In order to halt climate change and make a substantial contribution to climate protection, heating energy consumption must therefore be further reduced. The most effective way to do this is to maintain and renovate uninsulated buildings. This measure reduces not only heating costs but increases living comfort as well as the value of the building.:1 Introduction 1 1.1 (Internal) insulation of buildings 1 1.2 Who are these guides aimed at 1 2 Building assessment and humidity in buildings 2 3 Which types of walls are considered? 2 4 Planning phases 3 5 Planning and completion of on-site investigations 3 5.1 Information about the building 3 5.2 Planning 4 5.3 Implementation 5 6 Main sources of moisture in facades 8 6.1 Infiltration of driving rain through facades, façade elements or façade openings 8 6.2 Rising damp 12 6.3 Hygroscopic moisture and hygroscopic salts 13 6.4 Thermal bridges (condensation, mould) 15 7 Assessment of findings 16 7.1 Damage patterns associated with moisture 16 7.2 Façade materials influencing or accentuating humidity problems 18 8 Measuring methods 20 8.1 Measuring water content 21 8.2 Measurement of the capillary water absorption of the facade 24 8.3 Measuring room climate 25 8.4 Salt measurements 26 8.5 Further measurements 27 9 Literature 27 Appendix 28 A 1 Examples for typical, moisture-related damage patterns 28 Group 1 Typical damage patterns due to humidity 28 Group 2 Pathologies that may influence the presence of moisture in walls 39 Group 3 Façade elements that may influence humidity problems 48 Group 4 Façade materials that may influence humidity problems 53 A 2 Notes on the application of the measurement methods 59 A 3 Equipment and preparation for an inspection 64 A 4 Glossary 65 A 5 Flow Chart 66

[pt] O propósito do trabalho é avaliar a viabilidade técnica do uso de sondas tipo TDR e tensiômetros no monitoramento de encostas não saturadas. Com tais instrumentos, objetiva-se monitorar a variação da sucção mátrica e da umidade no solo em períodos chuvosos, visando aperfeiçoar os sistemas de alerta usados em áreas de risco e, consequentemente, minimizar perdas materiais e humanas. Para as medições, foram instalados uma estação meteorológica (munida de um pluviômetro, um datalogger, uma placa solar e uma antena para a transmissão de dados via internet), quatro sensores de umidade tipo TDR e um tensiômetro de alta capacidade em uma encosta localizada a montante da Faculdade de Medicina de Petrópolis, cidade da região serrana do estado do Rio de Janeiro. Foram registrados cerca de três meses de dados das sondas tipo TDR e, por conta de uma pane elétrica, apenas treze dias de dados do tensiômetro. As sondas tipo TDR apresentaram tempos de resposta rápidos, com nítidos aumentos de umidade volumétrica com o início de um evento chuvoso. Elas também apresentaram sensibilidade adequada para serem utilizadas em sistemas de alerta, sendo capazes de registrar alterações de umidade volumétrica com pequenos volumes de chuva. As curvas características encontradas através de ensaios de papel filtro mostraram um bom paralelo entre as sucções medidas diretamente pelo tensiômetro e aquelas obtidas indiretamente pelas sondas tipo TDR, através da conversão das umidades volumétricas em sucção. / [en] The purpose of this work is to evaluate the technical feasibility of using TDR probes and tensiometers to monitor unsaturated slopes. The objective is to monitor with these instruments the variation of matric suction and soil moisture during rainy periods, aiming to improve the warning systems used in hazardous areas and, consequently, to minimize human and material loss. For the measurements, a meteorological station (equipped with a rain gauge, a datalogger, a solar panel and an antenna for data transmission via internet), four TDR-type humidity sensors and a high capacity tensiometer were installed in a slope located in the University of Medicine of Petrópolis, city of the mountainous region of the state of Rio de Janeiro. Approximately three months of data were collected from the TDR probes and only thirteen days of tensiometer data due to a power outage. TDR-type probes showed fast response time, with clear increases in volumetric humidity with the beginning of a rainfall event. They also showed adequate sensitivity to be used in warning systems, being able to register changes in volumetric humidity with small precipitation amounts. The characteristic curves found by the filter method showed a good correlation with the suctions measured directly by the tensiometer and those obtained indirectly by the TDR probes, by converting the volumetric humidity into suction.

Diese Arbeit beschäftigt sich mit Aerial Rivers („luftgetragenen Flüssen“), den bevorzugten Wegen des Flusses von Feuchte in der Atmosphäre. Ziel ist es, die Voraussetzung für deren Integration in aktuelle Paradigmen der Wasserwirtschaft zu schaffen. Im Mittelpunkt der Arbeit stehen Amazonien und die angrenzenden Gebiete, also Regionen der Erde, in denen sich derzeit der Landnutzungswandel mit am schnellsten vollzieht. Aus theoretischer Sicht wird das Wissen über die Verbindung zwischen Aerial Rivers und Oberflächenflüssen erweitert. Mit Hilfe eines Algorithmus zur Verfolgung des atmosphärischen Feuchtigkeitstransports werden die Auswirkungen von entferntem Landnutzungswandel in Windrichtung auf die Niederschlagsmenge einer Zielregion quantifiziert. Die räumliche Heterogenität des Einflusses der gesamten Quellevapotranspirationsfläche (precipitationsehed) auf die/den empfangene/n Niederschlagsmenge/Oberflächenabfluss der Zielregion wird untersucht und führt zur Identifizierung der „Most Influential Precipitationshed“ (MIP), der für Managementzwecke relevantesten Teilfläche. Ein Aerial River-Managementbeispiel für Santa Cruz (Bolivien) zeigt, dass die strategische Wiederaufforstung im MIP sowohl die Niederschlagsmenge als auch den empfangenen Oberflächenabfluss erhöht und 22%-59% des zukünftigen Wasserbedarfszuwachses einer schnell wachsenden Stadt decken kann. Weiterhin werden sozio-technische Regime entlang von Aerial Rivers, die zu Extremereignissen wie Megadürren beitragen können, mit Hilfe der sozialwissenschaftlichen Methode der Multi-Level-Perspektive (MLP) untersucht. Ursachen wie Bodenpolitik und Marktinterventionen in Brasilien und Bolivien steuern weit entfernte kolumbianische Energieregime und deren Wandel. Aerial Rivers sind also zentral für zukünftiges Gewässermangement einschließlich Wasserkraft; ihr Management erfordert jedoch eine ganzheitliche Betrachtung der gesellschaftlichen Schnittstellen über administrative Grenzen und Sektoren hinweg. / Aerial rivers are the preferential pathways of moisture flows in the atmosphere. They connect the atmosphere, the water system, and the land system. This thesis aims to provide knowledge for integration of aerial rivers into management of these systems. It focuses on Amazonia and adjacent areas, which collectively experience some of the most rapid land use change on the planet. This thesis further develops three key aspects (theoretical, technical, and societal) of knowledge concerning aerial rivers. From a theoretical aspect, it advances the knowledge of connection between aerial rivers and surface rivers. Using a moisture tracking algorithm, the impact from upwind land use change via aerial rivers on target regions’ runoff reception is quantified. Spatial heterogeneity in the influence of the precipitationshed on runoff reception of the target region is found, implying a need to determine the most influential precipitationshed (MIP) for management purposes. From a technical aspect, the work demonstrates an aerial river management example for a rapidly growing city. It is shown that strategic reforestation in the MIP can increase both rainfall and runoff reception and secure 22%-59% of a rapidly growing city’s future water needs. Finally, the work explores the societal aspect of aerial river management. Socio-technical regimes along aerial rivers contributing to extreme events of mega-drought were traced through the social scientific method of multi-level perspective. It reveals that the source regimes such as land policy and market interventions in Brazil and Bolivia govern remote Colombian energy regimes and their transitions through aerial rivers. These findings show that aerial rivers are relevant and viable options for the development of future water resources - including hydropower - but their management will require a holistic consideration of the various societal interfaces as they cross jurisdictional boundaries and sectors.