Determination of organic matter burial rate in the inner Cadiz bay: Contribution of different habitats and possible sources of organic matter

Coastal habitats are important for global ocean production and provide important ecosystem services. The contribution of coastal ecosystem dominated by macrophytes to the global sequestration and burial of carbon may be important. The aim of this study is to determine the burial rate of C and N of characteristic habitats from Cadiz Bay and the sources of the organic matter being buried. The experimental design involved the analysis of key biogeochemical properties, like plant aboveground and belowground biomass, organic matter contents, C and N, and isotopic fractionation of C and N contents of the sediment, along a transect in the Trocadero Island saltmarshes, from a Zostera noltii dominated bed (S1) in the low saltmarsh, bare sediment (S2), an area of bare sediment with scattered Spartina maritima plants (S3), to a Spartina maritima dominated sediment in the high saltmarsh (S4). This transect represent a sea to land gradient in marine influence. These four habitats are characteristic of the Cadiz Bay Natural Park and of many other temperate saltmarshes. The horizontal heterogeneity in the biogeochemical characteristics within each habitat was high. The major differences in the biogeochemical characteristics of the sediment were related to the tidal height of each habitat, i.e., their position in the sea to land gradient. No significant differences were found in the content of organic matter between the different habitats. However, the content in carbonates was significantly lower in the most terrestrial habitat, S3 and S4, than in S1 and S2, being these two habitats more influenced by marine conditions. On the contrary, the organic C and total N content of the sediment tended to increase towards the land. In general, the vertical profiles of the biogeochemical properties did not show a clear trend with depth that might be due to intense mixing of the sediment surface. The analysis of δ13C and δ15N and the comparison with previous data suggest that the sediment organic matter seems to have multiple sources, although the organic matter derived from macroalgae and suspended particulate matter represented an important fraction. Our calculation indicates that between 73 - 123 g OM m-2 y-1 are buried in the inner bay, which represents organic C and total N burial rates of between 15.6 – 26.4 g C m-2 y-1, and 2.1 – 3.5 g N m-2 y-1, respectively. Thus, the total annual C and N burial rates for the inner bay, which has an area of 30 km2, of which the intertidal area is about 13 km2, are estimated to be about 630 t-C y-1 and 84 t-N y-1.This work was supported by the project of excellence “Funciones de la diversidad de macrófitos marinos bentónicos: mecanismos de control en el ciclo de nutrientes de zonas costeras someras” (FUNDIV, P07-RNM-02516) funded by the Junta de Andalucia and the European Union (FEDER) and by the National proyects “Interacciones entre las praderas de macrófitos marinos y la hidrodinámica: desde el organismo al ecosistema” (IMACHYDRO, CTM2008-0012/MAR) and “Microecología y cambios en los ciclos biogeoquímicos del carbono y el nitrógeno en sedimentos intermareales ocasionados por floraciones de macroalgas (MICROCHANGE)” (CTM2009-10736), both funded by the Spanish Ministry of Science and Technology and the European Union

Rate and temperature dependent plasticity and failure of AA7017-T73: experiments and modelling

En esta investigación se presenta el modelo de plasticidad utilizado para describir el comportamiento de la aleación de aluminio 7017-T73 bajo cargas uniaxiales. Para ello, se ha realizado una serie de ensayos de tracción uniaxial a diferentes velocidades de deformación con probetas mecanizadas en varias orientaciones con respecto a la dirección de laminación del material. Los resultados experimentales revelan que la AA7017-T73 presenta un alto grado de anisotropía tanto en el límite elástico como en el flujo plástico. También, cabe destacar que el material presenta muy poca sensibilidad a la velocidad de deformación. Además, la AA7017-T73 presenta deformaciones de rotura muy diferentes para cada orientación de carga. A la vista de los resultados experimentales obtenidos, para describir el comportamiento observado del material se emplea la función de plastificación Yld2000-3d con endurecimiento por deformación tipo Voce. Las simulaciones por elementos finitos muestran que el modelo de plasticidad utilizado es capaz de describir con precisión las respuestas local y global del material bajo cargas uniaxiales. Por último, se presenta el criterio de rotura Cockcroft-Latham para describir el comportamiento a fractura anisótropo de la AA7017-T73. A series of tensile tests on uniaxial specimens machined from different orientations with respect to the rolling direction was carried out at a wide range of loading rates for an aluminium 7017-T73 alloy. The experimental results revealed a high degree of anisotropy on both yield stress and plastic flow. In addition, the material showed very little strain-rate sensitivity. The measured fracture strains for different loading orientations showed large differences. In order to describe the material behaviour, the Yld2000-3d yield criterion and an isotropic Voce hardening model were used to describe the plasticity of the AA7017-T73. Finite element simulations showed that the plasticity model provided accurate predictions of local and global material responses under uniaxial loading. A Cockcroft-Latham failure criterion was presented for describing the anisotropic fracture behaviour of the AA7017-T73

On the loading-rate dependence of the Al 7017-T73 fracture-initiation toughness

While static fracture toughness is a widely studied and standardised parameter, its dynamic counterpart has not been exhaustively examined. Therefore, in this research a series of quasi-static and different loading-rate dynamic tests were carried out to determine the evolution of fracture toughness with the velocity of the application of the load on aluminium 7017-T73 alloy. Three-point bending tests of pre-fatigued standard specimens (ASTM E399) at four loading-rates were carried out. The experiments were conducted by employing the subsequent apparatus ordered from lowest to highest load application velocity: a servo-hydraulic universal testing machine, a free-drop tower, a modified Split Hopkinson Pressure Bar and an explosive load testing device. In order to perform the dynamic fracture toughness tests, it was necessary to design and develop some experimental devices. The fracture-initiation toughness of the aluminium 7017-T73 alloy did not exhibit a significant variation for the studied cases. As a conclusion, the research showed that fracture-initiation toughness remained constant regardless of the velocity at which the load was applied

Tenacidad de fractura dinámica de iniciación a diferentes velocidades de solicitación: técnicas experimentales

En esta investigación se presentan diversos dispositivos experimentales diseñados para la realización de ensayos de tenacidad de fractura a diferentes velocidades de solicitación. Se realizan ensayos de flexión en tres puntos de probetas normalizadas (ASTM E399) empleando una máquina servohidráulica, una torre de caída, una barra Hopkinson modificada y un dispositivo especialmente diseñado para trabajar con cargas explosivas. Para poder validar dichos dispositivos experimentales, se realizan estos ensayos sobre un material independiente de la velocidad de deformación; dicho material es la aleación de aluminio 7017-T73. Todos los ensayos realizados sobre dicha aleación dieron el mismo valor de tenacidad de fractura dinámica de iniciación; por lo tanto, los dispositivos experimentales diseñados se consideraron válidos para este fin. Una vez validada la técnica experimental, se llevan a cabo ensayos de flexión en tres puntos en un material dependiente de la velocidad de deformación. Por lo tanto, los dispositivos experimentales diseñados fueron utilizados para determinar la tenacidad de fractura dinámica de iniciación del acero Mars 240. Los resultados obtenidos muestran que, en el caso de este acero, la tenacidad de fractura dinámica de iniciación aumenta con la velocidad de solicitación. ---------- ABSTRACT---------- The design and development of different experimental devices for the purpose of performing fracture toughness tests at different loading-rates are presented. Three-point bending tests of pre-fatigued standard specimens (ASTM E399) were carried out employing a servo-hydraulic universal testing machine, a free-drop tower, a modified Split Hopkinson Pressure Bar and an explosive load transferring device. A rate-independent alloy, a 7017-T73 aluminium alloy, was selected in order to validate such devices. All of the 7017-T73 aluminium alloy experiments provided the same value of the dynamic fracture-initiation toughness. Therefore, the developed devices were validated and considered suitable for such a purpose. Fracture toughness test of a rate-dependent armour steel, a Mars240 steel, employing the developed devices, were performed in order to determine the evolution of the dynamic fracture-initiation toughness with the loading-rate. In this case, the dynamic fracture-initiation toughness values of the Mars 240 steel increased with the velocity of the application of the load

An experimental and numerical study of ductile failure under quasi-static and impact loadings of Inconel 718 nickel-base superalloy

A numerical and experimental study of ballistic impacts at various temperatures on precipitation hardened Inconel 718 nickel-base superalloy plates has been performed. A coupled elastoplastic-damage constitutive model with Lode angle dependent failure criterion has been implemented in LS-DYNA non-linear finite element code to model the mechanical behaviour of such an alloy. The ballistic impact tests have been carried out at three temperatures: room temperature (25 °C), 400 °C and 700 °C. The numerical study showed that the mesh size is crucial to predict correctly the shear bands detected in the tested plates. Moreover, the mesh size convergence has been achieved for element sizes on the same order that the shear bands. The residual velocity as well as the ballistic limit prediction has been considered excellent for high temperature ballistic tests. Nevertheless, the model has been less accurate for the numerical simulations performed at room temperature, being though in reasonable agreement with the experimental data. Additionally, the influence that the Lode angle had on quasi-static failure patterns such as cup-cone and slanted failure has been studied numerically. The study has revealed that the combined action of weakened constitutive equations and Lode angle dependent failure criterion has been necessary to predict the previously-mentioned failure pattern

Identificación de variedades autóctonas de vid en zonas transfronterizas del Duero

Castilla y León cuenta con una zona vitivinícola transfronteriza con el norte de Portugal, la DO Arribes, que linda con la región de Tras-os-Montes, en la que se ubica la Indicación de Procedencia Reglamentada PlanaltoMirandês. En ambas zonas vitivinícolas existe un elevado número de variedades minoritarias que cuentan con escasos individuos distribuidos demodo disperso en viñedos de reducidas dimensiones que son difíciles de localizar e identificar. Se ha llevado a cabo una minuciosa prospección en 2006, 2007 y 2008 en ambas zonas vitivinícolas y se ha logrado identificar un apreciable número de variedades combinando la descripción ampelográfica y el análisismolecular (SSR), así como establecer diferentes sinonimias usadas tanto en España como en Portugal

Effect of the temperature, strain rate and microstructure on flow and fracture characteristics of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD alloy

A series of quasi-static and dynamic tensile tests at varying temperatures were carried out to determine the mechanical behaviour of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD as-HIPed alloy. The temperature for the tests ranged from room temperature to 850  ∘C. The effect of the temperature on the ultimate tensile strength, as expected, was almost negligible within the selected temperature range. Nevertheless, the plastic flow suffered some softening because of the temperature. This alloy presents a relatively low ductility; thus, a low tensile strain to failure. The dynamic tests were performed in a Split Hopkinson Tension Bar, showing an increase of the ultimate tensile strength due to the strain rate hardening effect. Johnson-Cook constitutive relation was used to model the plastic flow. A post-testing microstructural of the specimens revealed an inhomogeneous structure, consisting of lamellar α2 + γ structure and γ phase equiaxed grains in the centre, and a fully lamellar structure on the rest. The assessment of the duplex-fully lamellar area ratio showed a clear relationship between the microstructure and the fracture behaviour

Grain size gradient length scale in ballistic properties optimization of functionally graded nanocrystalline steel plates

The last few years have highlighted the existence of two relevant length scales in the quest to ultrahigh-strength polycrystalline metals. Whereas the microstructural length scale – e.g. grain or twin size – has mainly be linked to the well-established Hall–Petch relationship, the sample length scale – e.g. nanopillar size – has also proven to be at least as relevant, especially in microscale structures. In this letter, a series of ballistic tests on functionally graded nanocrystalline plates are used as a basis for the justification of a “grain size gradient length scale” as an additional ballistic properties optimization parameter

Management of advanced ovarian cancer in Spain: an expert Delphi consensus

Malaltia avançada; Consens; Càncer d'ovarisEnfermedad avanzada; Consenso; Cáncer de ovariosAdvanced disease; Consensus; Ovarian cancerBackground To determine the state of current practice and to reach a consensus on recommendations for the management of advanced ovarian cancer using a Delphi survey with a group of Spanish gynecologists and medical oncologists specially dedicated to gynecological tumors. Methods The questionnaire was developed by the byline authors. All questions but one were answered using a 9-item Likert-like scale with three types of answers: frequency, relevance and agreement. We performed two rounds between December 2018 and July 2019. A consensus was considered reached when at least 75% of the answers were located within three consecutive points of the Likert scale. Results In the first round, 32 oncologists and gynecologists were invited to participate, and 31 (96.9%) completed the online questionnaire. In the second round, 27 (87.1%) completed the online questionnaire. The results for the questions on first-line management of advanced disease, treatment of patients with recurrent disease for whom platinum might be the best option, and treatment of patients with recurrent disease for whom platinum might not be the best option are presented. Conclusions This survey shows a snapshot of current recommendations by this selected group of physicians. Although the majority of the agreements and recommendations are aligned with the recently published ESMO-ESGO consensus, there are some discrepancies that can be explained by differences in the interpretation of certain clinical trials, reimbursement or accessibility issues.This study was sponsored by TESARO without restriction, nowadays a GlaxoSmithkline company

Phase 2 Trial (POLA Study) of Lurbinectedin plus Olaparib in Patients with Advanced Solid Tumors: Results of Efficacy, Tolerability, and the Translational Study

Endometrial cancer; Genomic instability; OlaparibCáncer endometrial; Inestabilidad genómica; OlaparibCàncer d'endometri; Inestabilitat genòmica; OlaparibWe hypothesized that the combination of olaparib and lurbinectedin maximizes DNA damage, thus increasing its efficacy. The POLA phase 1 trial established the recommended phase 2 dose of lurbinectedin as being 1.5 mg (day 1) and that of olaparib as being 250 mg/12 h (days 1–5) for a 21-day cycle. In phase 2, we explore the efficacy of the combination in terms of clinical response and its correlation with mutations in the HRR genes and the genomic instability (GI) parameters. Results: A total of 73 patients with high-grade ovarian (n = 46), endometrial (n = 26), and triple-negative breast cancer (n = 1) were treated with lurbinectedin and olaparib. Most patients (62%) received ≥3 lines of prior therapy. The overall response rate (ORR) and disease control rate (DCR) were 9.6% and 72.6%, respectively. The median progression-free survival (PFS) was 4.54 months (95% CI 3.0–5.2). Twelve (16.4%) patients were considered long-term responders (LTR), with a median PFS of 13.3 months. No clinical benefit was observed for cases with HRR gene mutation. In ovarian LTRs, although a direct association with GI and a total loss of heterozygosity (LOH) events was observed, the association did not reach statistical significance (p = 0.055). Globally, the total number of LOHs might be associated with the ORR (p =0.074). The most common grade 3–4 toxicities were anemia and thrombocytopenia, in 6 (8.2%) and 3 (4.1%) patients, respectively. Conclusion: The POLA study provides evidence that the administration of lurbinectedin and olaparib is feasible and tolerable, with a DCR of 72.6%. Different GI parameters showed associations with better responses.This trial was sponsored by AstraZeneca and PharmaMar, including supply of the drugs used in this study