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Here, a degraded soil, located in a semi-arid Mediterranean region, was characterized 17 years after organic amendment with sludge or compost (differing in their stabilization degree) for restoration purposes. To do this, (i) soil physicochemical properties and plant cover, (ii) soil organic matter (SOM) content and composition, (iii) soil basal respiration and enzymatic activities, and (iv) abundance, taxonomic composition, and functionality (shotgun metagenomics) of microbial communities were studied. Increased SOM and nutrient contents were found in soil from amended plots with respect to the control, with no differences between amendment types. This is explained by the lasting effects of organic amendments and the higher plant cover. Thermal and pyrolytic analyses showed that the restoration process enriched soil mainly with SOM of intermediate recalcitrance and of high chemical diversity. SOM composition did not differ between amendment types. Increased microbial abundances and activities were found in the amended plots, without differences between compost and sludge. Shotgun metagenomics showed that microbial communities changed in taxonomic and functional terms between amended and unamended plots, but these differences were rather limited. The taxonomic differences between treatments were mainly driven by increasing abundances of Actinobacteria and decreasing abundances of Proteobacteria in soil from amended plots. Soil microbial communities in amended plots showed some functional adaptation to the increased nutrient contents and predominant nutrients forms. This, together with the higher microbial abundances detected, explained the conspicuous soil enzymatic activities reported in amended plots. The effectiveness of the studied soil restoration process was confirmed here from an integrative perspective.

Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha−1 in the top 30 cm and 231 ± 134 Mg SOC ha−1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies.

Removing lampenflora, phototrophic organisms developing on rock surfaces in tourist cavities due to the artificial lighting, is a challenge for sustainable and appropriate long-term management of caves. Photosynthetic-based biofilms usually cause rock biodeterioration and an ecological imbalance in cave ecosystems. In this work, a detailed investigation of the effects of the 3 most commonly used lampenflora cleaning operations (NaClO, H2O2 and UVC) was carried out in Pertosa-Auletta Cave (Italy). The application of NaClO showed good disinfection capability over extended periods of time without causing any appreciable rock deterioration. The H2O2 treatment showed to be corrosive for the rock surfaces covered with vermiculation deposits. The chemical alteration of organic and inorganic compounds by H2O2 did not remove biomass, favoring biofilm recovery after three months of treatment. Both NaClO and H2O2 treatments were effective at removing photoautotrophs, although the bacterial phyla Proteobacteria and Bacteroidetes as well as Apicomplexa and Cercozoa among the Eukaryotes, were found to be resistant to these treatments. The UVC treatments did not show any noticeable effect on the biofilms.

Soils represent an essential natural, practically non-renewable resource that provides many critical ecosystem services necessary for life. Furthermore, soils play a critical role in maintaining the balance of the carbon cycle, acting as the largest terrestrial carbon pool which made them crucial in mitigating climate change. Understanding the complexity and dynamics of soils is, therefore, apart from preserving and managing this valuable natural resource, critical for the benefit of current and future generations. However, the changing climate and increasing intensity of agricultural production pose significant threats to the sustainability and role of soils, mainly by contributing to a depletion in soil organic matter (SOM) and altering its dynamics. Indeed, Mediterranean soils face these threats in a more severe way due to their geographic location, particular climate and inherent low content of SOM. It is critical to shedding light on this respect by combining different analytical procedures and providing complementary and valuable information on processes that regulate the accumulation, decomposition, and transformation of SOM. The main objective of this thesis was to investigate and deepen our knowledge about the two main threads affecting carbon dynamics in Mediterranean soils i.e., climate change and intensive agricultural practices. For this, advanced analytical techniques appropriate for the study of complex matrices such are soils were tested and combined to study SOM in two distinct and representative Mediterranean soils, in terms of extension and ecosystem relevance: Mediterranean savannahs, commonly known as “dehesas” (Section I) and agricultural soils (Section II).

Slash-and-burn of Amazon Forest (AF) for pasture establishment has increased the occurrence of AF wildfires. Recent studies emphasize soil organic matter (SOM) molecular composition as a principal driver of post-fire forest regrowth and restoration of AF anti-wildfire ambience. Nevertheless, SOM chemical shifts caused by AF fires and post-fire vegetation are rarely investigated at a molecular level. We employed pyrolysis–gas chromatography–mass spectrometry to reveal molecular changes in SOM (0–10, 40–50 cm depth) of a slash-burn-and-20-month-regrowth AF (BAF) and a 23-year Brachiaria pasture post-AF fire (BRA) site compared to native AF (NAF). In BAF (0–10 cm), increased abundance of unspecific aromatic compounds (UACs), polycyclic aromatic hydrocarbons (PAHs) and lipids (Lip) coupled with a depletion of polysaccharides (Pol) revealed strong lingering effects of fire on SOM. This occurs despite fresh litter deposition on soil, suggesting SOM minimal recovery and toxicity to microorganisms. Accumulation of recalcitrant compounds and slow decomposition of fresh forest material may explain the higher carbon content in BAF (0–5 cm). In BRA, SOM was dominated by Brachiaria contributions. At 40–50 cm, alkyl and hydroaromatic compounds accumulated in BRA, whereas UACs accumulated in BAF. UACs and PAH compounds were abundant in NAF, possibly air-transported from BAF.

Today’s agriculture has the challenge of ensuring food supply for a growing population while human activity has already deteriorated about 40% of the world’s soils, reducing productive capacity and increasing reliance on mineral fertilizers. In this context, valorizing and recycling mineral and agricultural waste for use as substrates or soil supplements enhance a sustainable economy, as well as the development of activities focused on finishing the soil nutrients’ cycle. Looking for an effective solution to the massive waste generation and to enhance the agronomic qualities of soils, this study investigates the agronomic impact of contrasting inorganic and organic materials such as green compost (GC), wood biochar (WB), rice husk ash (RA), and volcanic ash (VA) as amendments to an alkaline Luvisol under controlled conditions. In this sense, barley seeds were planted and grown in a greenhouse under controlled conditions for 60 days on a soil amended with the aforementioned materials. The amendments demonstrated appropriate attributes for improving soil agronomic properties, enhancing the soil’s nutritional content with no effect on barley germination. The WB showed high aromaticity and abundance of refractory organic C. Both ash-rich amendments showed high P and K contents, which are important elements for plant development. The GC has high water retention capacity and an adequate C and N balance. Although the application of the amendments had no effect on barley yields, the plants from the ash-amended pots showed an increase of Photosystem II efficiency, indicative of a better physiological status. In terms of toxicological safety, the abundance of trace elements in soils and plants was investigated. All soils met the maximum allowable limits for these persistent pollutants. Nevertheless, longer-term tests on plants are required to determine the risk of Pb accumulation, particularly in soils amended with GC and compost-ash mixtures. The simultaneous combination of

Mediterranean savannahs (dehesas) are agro-sylvo-pastoral systems with a marked seasonality, with severe summer drought and favourable rainy spring and autumn. These conditions are forecasted to become more extreme due to the ongoing global climate change. Under such conditions, it is key to understand soil organic matter (SOM) dynamics at a molecular level. Here, analytical pyrolysis (Py-GC/MS) combined with chemometric statistical approaches was used for the molecular characterization of SOM in a five-years field manipulative experiment of single and combined rainfall exclusion (drought) and increased temperature (warming). The results indicate that SOM molecular composition in dehesas is mainly determined by the effect of the tree canopy. After only five years of the climatic experiment, the differences caused by the warming, drought and the combination of warming+drought forced climate scenarios became statistically significant with respect to the untreated controls, notably in the open pasture habitat. The climatic treatments mimicking foreseen climate changes affected mainly the lignocellulose dynamics, but also other SOM compounds (alkanes, fatty acids, isoprenoids and nitrogen compounds) pointing to accelerated humification processes and SOM degradation when soils are under warmer and dryer conditions. Therefore, it is expected that, in the short term, the foreseen climate change scenarios will exert changes in the Mediterranean savannah SOM molecular structure and in its dynamic.

Organic carbon (OC) association with soil minerals stabilizes OC on timescales reflecting the strength of mineral–C interactions. We applied ramped thermal oxidation to subsoil B horizons with different mineral–C associations to separate OC according to increasing temperature of oxidation, i.e. thermal activation energy. Generally, OC released at lower temperatures was richer in bioavailable forms like polysaccharides, while OC released at higher temperatures was more aromatic. Organic carbon associated with pedogenic oxides was released at lower temperatures and had a narrow range of 14C content. By contrast, N-rich compounds were released at higher temperatures from samples with 2 : 1 clays and short-range ordered (SRO) amorphous minerals. Temperatures of release overlapped for SRO minerals and crystalline oxides, although the mean age of OC released was older for the SRO. In soils with more mixed mineralogy, the added presence of older OC released at temperatures greater than 450°C from clays resulted in a broader distribution of OC ages within the sample, especially for soils rich in 2 : 1 layer expandable clays such as smectite. While pedogenic setting affects mineral stability and absolute OC age, mineralogy controls the structure of OC age distribution within a sample, which may provide insight into model structures and OC dynamics under changing conditions.

This paper proposes a new Fluid–Structure Interaction computational framework. The coupling between the solid and an incompressible fluid is formulated by means of the method of localized Lagrange multipliers (LLM). Instead of applying a direct coupling between the fluid and the structure, which is the traditional approach, LLM introduces an intermediate surface with its own degrees of freedom that is connected to the fluid and structure sides using independent fields of localized Lagrange multipliers. This approach allows the connection of non-matching meshes with mortar or classical localized methods and provides consistent dynamic equations of motion for the interface that can be integrated in parallel. Interface multipliers are later eliminated and the interface motion is used to update the fluid and structure states. This way, dedicated stand-alone software modules for the fluid and the structure are connected to a third interface system treating their interaction, thus preserving the modularity of the single-discipline software modules. Different numerical examples are solved with the proposed methodology to prove its efficiency and accuracy by running a series of classical dynamic FSI benchmark problems.

Mediterranean savannahs (dehesas) are agro-sylvo-pastoral systems with a marked seasonality, with severe summer drought and favourable rainy spring and autumn. These conditions are forecasted to become more extreme due to the ongoing global climate change. Under such conditions, it is key to understand soil organic matter (SOM) dynamics at a molecular level. Here, analytical pyrolysis (Py-GC/MS) combined with chemometric statistical approaches was used for the molecular characterization of SOM in a five-years field manipulative experiment of single and combined rainfall exclusion (drought) and increased temperature (warming). The results indicate that SOM molecular composition in dehesas is mainly determined by the effect of the tree canopy. After only five years of the climatic experiment, the differences caused by the warming, drought and the combination of warming+drought forced climate scenarios became statistically significant with respect to the untreated controls, notably in the open pasture habitat. The climatic treatments mimicking foreseen climate changes affected mainly the lignocellulose dynamics, but also other SOM compounds (alkanes, fatty acids, isoprenoids and nitrogen compounds) pointing to accelerated humification processes and SOM degradation when soils are under warmer and dryer conditions. Therefore, it is expected that, in the short term, the foreseen climate change scenarios will exert changes in the Mediterranean savannah SOM molecular structure and in its dynamic.

Today’s agriculture has the challenge of ensuring food supply for a growing population while human activity has already deteriorated about 40% of the world’s soils, reducing productive capacity and increasing reliance on mineral fertilizers. In this context, valorizing and recycling mineral and agricultural waste for use as substrates or soil supplements enhance a sustainable economy, as well as the development of activities focused on finishing the soil nutrients’ cycle. Looking for an effective solution to the massive waste generation and to enhance the agronomic qualities of soils, this study investigates the agronomic impact of contrasting inorganic and organic materials such as green compost (GC), wood biochar (WB), rice husk ash (RA), and volcanic ash (VA) as amendments to an alkaline Luvisol under controlled conditions. In this sense, barley seeds were planted and grown in a greenhouse under controlled conditions for 60 days on a soil amended with the aforementioned materials. The amendments demonstrated appropriate attributes for improving soil agronomic properties, enhancing the soil’s nutritional content with no effect on barley germination. The WB showed high aromaticity and abundance of refractory organic C. Both ash-rich amendments showed high P and K contents, which are important elements for plant development. The GC has high water retention capacity and an adequate C and N balance. Although the application of the amendments had no effect on barley yields, the plants from the ash-amended pots showed an increase of Photosystem II efficiency, indicative of a better physiological status. In terms of toxicological safety, the abundance of trace elements in soils and plants was investigated. All soils met the maximum allowable limits for these persistent pollutants. Nevertheless, longer-term tests on plants are required to determine the risk of Pb accumulation, particularly in soils amended with GC and compost-ash mixtures. The simultaneous combination of

Soils represent an essential natural, practically non-renewable resource that provides many critical ecosystem services necessary for life. Furthermore, soils play a critical role in maintaining the balance of the carbon cycle, acting as the largest terrestrial carbon pool which made them crucial in mitigating climate change. Understanding the complexity and dynamics of soils is, therefore, apart from preserving and managing this valuable natural resource, critical for the benefit of current and future generations. However, the changing climate and increasing intensity of agricultural production pose significant threats to the sustainability and role of soils, mainly by contributing to a depletion in soil organic matter (SOM) and altering its dynamics. Indeed, Mediterranean soils face these threats in a more severe way due to their geographic location, particular climate and inherent low content of SOM. It is critical to shedding light on this respect by combining different analytical procedures and providing complementary and valuable information on processes that regulate the accumulation, decomposition, and transformation of SOM. The main objective of this thesis was to investigate and deepen our knowledge about the two main threads affecting carbon dynamics in Mediterranean soils i.e., climate change and intensive agricultural practices. For this, advanced analytical techniques appropriate for the study of complex matrices such are soils were tested and combined to study SOM in two distinct and representative Mediterranean soils, in terms of extension and ecosystem relevance: Mediterranean savannahs, commonly known as “dehesas” (Section I) and agricultural soils (Section II). Chapter 1 presents an introduction to the role of soils in climate change, different strategies that have been addressed and why Mediterranean soils should receive special consideration given their distinct carbon dynamics. Hence, a cluster of diverse analytical approaches is prefaced for t, Los suelos representan un recurso natural prácticamente no renovable y esencial que proporciona muchos servicios ecosistémicos críticos necesarios para la vida. Además, los suelos desempeñan un papel fundamental en el mantenimiento del ciclo del carbono, actuando como la mayor reserva de carbono orgánico de la superficie terrestre, lo que los convierte en cruciales para mitigar el cambio climático. Comprender la complejidad y la dinámica de los suelos es, por tanto, además de preservar y gestionar este valioso recurso natural, fundamental para el beneficio de las generaciones actuales y futuras. Sin embargo, el cambio climático y la creciente intensidad de la producción agrícola plantean amenazas significativas para la sostenibilidad y el papel de los suelos, principalmente al contribuir a un agotamiento de la materia orgánica del suelo y alterar la dinámica de la materia orgánica del suelo (MOS). De hecho, los suelos mediterráneos se enfrentan a estas amenazas de forma más severa debido a su situación geográfica, clima particular y bajo contenido inherente de materia orgánica. Es fundamental arrojar luz a este respecto combinando diferentes procedimientos analíticos y proporcionando información complementaria y valiosa sobre los procesos que regulan la acumulación, descomposición y transformación de la MOS. El objetivo principal de esta tesis ha sido investigar y profundizar en el conocimiento de los dos hilos conductores que afectan a la dinámica del carbono en los suelos mediterráneos: el cambio climático y las prácticas agrícolas intensivas. Para ello, se probaron y combinaron técnicas analíticas avanzadas apropiadas para el estudio de matrices complejas como son los suelos para estudiar la MOS en dos suelos mediterráneos distintos y representativos, en términos de extensión y relevancia ecosistémica: Las sabanas mediterráneas, comúnmente conocidas como "dehesas" (Sección I) y los suelos agrícolas (Sección II). El Capítulo 1 presenta una introducción al papel de

61 p. -- Bibliogr.: p. 60-61, Eraikin baten eraginkortasun termikoa aztertzeko hainbat tenperatura sentsoreren analisia, inplementazioa eta sentsore guztiak bateratzen dituen PCB plaka baten eraikuntza.

59 p. -- Bibliogr.: p. 59, Txosten honetan DC/DC-ko (Direct Current edo Korronte Zuzena) bihurgailu isolatu baten transformadore baten neurketa, analisia eta 3D simulazio elektromagnetikoa egingo da. Proiektu hau prozedura desberdinetan banatua egongo da, lehenik bihurgailuarentzako transformadore baten diseinua eta muntaketa egingo da eta bere parametroak era desberdinetan neurtuko dira. Ondoren transformadorearen portaera aztertuko da 3D simulazio elektromagnetikoaren bidez eta azkenik lortutako emaitza guztiak konparatuko dira.

A new formulation for the displacement-only partitioned equations of motion for linear structures is presented, which employs: the partitioned displacement, acceleration, and applied force ( ); the partitioned block diagonal mass and stiffness matrices ( ); and, the coupling projector ( ), yielding the partitioned coupled equations of motion: ). The key element of the proposed formulation is the coupling projector ( ) which can be constructed with the partitioned mass matrix ( ), the Boolean matrix that extracts the partition boundary degrees of freedom ( ), and the assembly matrix ( ) relating the assembled displacements ( ) to the partitioned displacements ( ) via . Potential utility of the proposed formulation is illustrated as applied to six proof-of-concept problems in an ideal setting: unconditionally stable explicit-implicit transient analysis, static parallel analysis in an iterative solution mode; reduced-order modeling (component mode synthesis); localized damage identification which can pinpoint damage locations; a new procedure for partitioned structural optimization; and, partitioned modeling of multiphysics problems. Realistic applications of the proposed formulation are presently being carried out and will be reported in separate reports.

The derivation and implementation of an asynchronous direct time integration scheme for domain-decomposed finite element models is presented. To maximize clarity in the description of the proposed asynchronous integration, the scheme is restricted to the linear-elastic stress wave propagation case. The proposed method allows the integration of individual subdomains with independent time steps. There is no requirement for an integer time steps ratio of the interacting domains while maintaining zero interface energy. The subdomains are connected by the condition of the continuity of the acceleration field at the interface. In addition, the a posteriori technique is applied to satisfy the continuity of the displacement and velocity fields. Another important contribution of this paper lies in the description of the implementation — we offer the reader a general description of the implementation of the case of any number of subdomains with any number of constraints between them, while the basics of the algorithm are explained on a single domain pair. The functionality of the asynchronous integrator is verified by solving selected problems and comparing with analytical solutions and experimental measurements obtained using a Split Hopkinson pressure bar setup.