Over length quantification of the multiaxial mechanical properties of the ascending, descending and abdominal aorta using Digital Image Correlation

In this paper, we hypothesize that the biaxial mechanical properties of the aorta may be dependent on arterial location. To demonstrate any possible position-related difference, our study analyzed and compared the biaxial mechanical properties of the ascending thoracic aorta, descending thoracic aorta and infrarenal abdominal aorta stemming from the same porcine subjects, and reported values of constitutive parameters for well-known strain energy functions, showing how these mechanical properties are affected by location along the aorta. When comparing ascending thoracic aorta, descending thoracic aorta and infrarenal abdominal aorta, abdominal tissues were found to be stiffer and highly anisotropic. We found that the aorta changed from a more isotropic to a more anisotropic tissue and became progressively less compliant and stiffer with the distance to the heart. We observed substantial differences in the anisotropy parameter between aortic samples where abdominal samples were more anisotropic and nonlinear than the thoracic samples. The phenomenological model was not able to capture the passive biaxial properties of each specific porcine aorta over a wide range of biaxial deformations, showing the best prediction root mean square error e=0.2621 for ascending thoracic samples and, especially, the worst for the infrarenal abdominal samples e=0.3780. The micro-structured model with Bingham orientation density function was able to better predict biaxial deformations (e=0.1372 for ascending thoracic aorta samples). The root mean square error of the micro-structural model and the micro-structured model with von Mises orientation density function were similar for all positions

Failure damage mechanical properties of thoracic and abdominal porcine aorta layers and related constitutive modeling: phenomenological and microstructural approach

Despite increasing experimental and analytical efforts to investigate the irreversible effects of arterial tissue failure, the underlying mechanisms are still poorly understood. The goal of this study was to characterize the failure properties of the intact wall and each separated layer (intima, media, and adventitia) of the descending thoracic and infrarenal abdominal aorta and to test the hypothesis that the failure properties of layer-separated tissue depend on the location of the aorta. To test this hypothesis, we performed uniaxial tests to study the mechanical behavior of both intact and layer-separated porcine aortic tissue samples taken from descending thoracic and infrarenal abdominal aorta until complete failure. The fracture stress is higher in the infrarenal abdominal aorta than in the equivalent descending thoracic aorta. It was also found that the extrapolation of the elastic mechanical properties from the physiological to the supra-physiological regime for characterizing the mechanical response of the aorta would be inappropriate. Finally, we report values of constitutive parameters using phenomenological and microstructural damage models based on continuum damage mechanics theory. The phenomenological damage model gives an excellent fit to the experimental data compared to the microstructural damage model. Although the fitting results of the phenomenological model are better, the microstructural models can include physically motivated aspects obtained from experiments

El amortiguamiento frontal de la estructura de la cobertera surpirenaica y su relación con el anticlinal de Barbastro-Balaguer

La estructura de la parte frontal del sector central del Pirineo Meridional esta constituida por una sucesión de escamas imbricadas generalmente con escasa deformación interna por plegamiento. En el conjunto de estas escamas se distinguen tres sectores (Montsec, Sierras Marginales y franja de Terciario continental despegado) limitadas por los accidentes principales que denominamos cabalgamrento del Montsec, cabalgamrento inferror de las Sierras Marginales y cabalgamiento de San Esteban de Lrtera. Este Último emerge en el anticlinal de Barbastro-Balaguer y tiene como nivel de despegue la base de los yesos del Eoceno en vez del Keuper, tan  generalizado en el dominio surpirenaico.Un corte compensado refleja un acortamiento de unos 11 km entre ei frente del Montsec y el cabalgamiento inferior de las Sierras Marginales. Una tentativa de prolongación de este corte hasta el an-tepais indeformado sugiere un acortamiento de mas del 60 por cientoto, implicando un desplazamiento del Montsec de 56 km

Evolutive 3D modeling: A proposal for a new generative design methodology

At present, traditional 3D modeling programs consist of a set of tools that reflect conventional means of mechanical manufacturing and have limitations in relation with the current manufacturing capacities. On the other hand, organic and morphing 3D modeling programs are designed to transform a model from one known shape to another also known shape. Generative design helps the designers to detach themselves during the design process and can provide them with completely unexpected geometrical solutions. In this paper, starting from 3D morphing techniques and genetic algorithms, a new methodology of product shape definition is developed, capable of imitating processes that occur in nature and aimed at creating new and different product designs. This methodology enables to overcome the limitations imposed by design fixation and allows better exploitation of the great possibilities granted by the new manufacturing techniques, most notably additive manufacturing. The initial process of research and information gathering gives this work a solid basis to develop the new methodology. The results of this initial process are briefly resumed in this paper in order to explain the main motivation for developing this work. The workflow of this methodology is presented as a theoretical process, since its implementation has not been, at least for the moment, put into practice. Before presenting the conclusion for this proposal, several examples have been formulated in order to help the reader to catch the point of the entire process

Operational thresholds of moored ships at the oil terminal of inner port of A Coruña (Spain)

[Abstract] Minimizing the stay of a vessel in port can lead to improvements in harbor efficiency. Currently, downtimes of cargo operations or their performance reduction because of excessive vessel motion are especially relevant. This work aims to evaluate the operational conditions of moored vessels in the inner port of A Coruña (Spain), comparing them with motion thresholds established by international standards for cargo operations. To this end, motions of 19 ships were monitored. Data analysis revealed large angular motions, particularly roll and yaw, including amplitudes that exceeded the limiting criteria of the standards in most of the analyzed vessels, with no registered downtime. Regarding linear movements, heave and surge recorded lower amplitudes compared to the values of standard thresholds. The specific behavior of each vessel was analyzed in terms of its size, maritime conditions, and mooring location. Field campaigns such as those performed in this work are an effective way of analyzing the operational conditions of ports, which could help in identifying problems in the mooring zone.Ministerio de Economía, Industria y Competitividad; BIA2017-86738-

Rasgos sedimentarios de los conglomerados miocénicos del borde noreste de la Depresión de Granada

Este trabajo da una primera interpretación sedimentaria y una reconstrucción paleogeográfica de los materiales conglomeráticos neógenos de parte de la Depresión de Granada. El modelo sedimentario propuesto consiste en abanicos aluviales que penetran en medio marino. En una fase posterior, se establece un régimen fluvial que desemboca en zonas lacustres, eventualmente evaporÍticas. [ABSTRACT] This paper offers a first sedimentary interpretation aod a paleogeographic reconstruction for the neogenic conglomerates in a part of Granada Basin. The proposed sedimentary ruodel consists on alluvial fans going into marine environment. Later, a braided fluviatile pattern connected downstream with lacllstrine areas with episodic evaporite deposits establishes in this place

Filling gaps: closing the life cycle of the endangered Mediterranean limpet Patella ferruginea Gmelin, 1791 (Gastropoda, Patellidae)

Several reproductive issues and the larval development of the ferruginous limpet, Patella ferruginea Gmelin, 1791, an endangered species endemic from the western Mediterranean Sea, were studied to fill gaps in the knowledge of its life cycle. Average diameter of mature oocytes was 141.83 μm and mean oocyte density in the ovary was 283,800 oocytes/gram. No significant correlations were found between both oocyte diameter or density and female shell length. Female fecundity (number of oocytes per gonad) was significantly correlated with shell length and varied between 189,200 oocytes in a 40.0 mm female and 5,019,200 oocytes in an 86.4 mm female. However, there was considerable variability, in particular for largest females. Spawning induction was not achieved using usual molluscan aquaculture methods. Thus, oocytes obtained after dissection of females were used for fertilizations trials. Alkalinization treatments of seawater were used to test improvement in oocyte maturation and later fertilization rates. Treatment at pH 9 during 2 h produced the highest increase in the percentage of mature oocytes and in the fertilization rate; but these results showed high variability and were mainly significant when the initial degree of maturation was low. Sperm concentration experiments determined that best in vitro fertilization were performed at 105 and 5×105 spermatozoids/ml. The sequence and timing of the complete larval development of Patella ferruginea in laboratory conditions is described and illustrated here for the first time. At 20 °C, larvae became competent for metamorphosis 3 days after fertilization, but some crawling pediveliger larvae with a still well developed velum were found even 7 days after fertilization. Recruits 1-2 mm in length were achieved in low numbers from two of the last assays and were first detected between 131-141 days after fertilization. The resulting juveniles were monitored during two years and sex determination of five survivors at the end of this period showed that two were mature males, two mature females and one indeterminate. Our results show that the main reproductive traits or larval development of P. ferruginea hardly differ from those of other non-endangered Mediterranean or NE Atlantic limpet species. Therefore, its decline cannot be mainly attributed to some constraints of these traits as was previously suggested, but to human impact. On the other hand, it is feasible to complete the life cycle of this species in laboratory conditions, from fertilized eggs to mature individuals. However, an important part of the process like spawning induction was not achieved as gonads needed to be dissected fatally from females, although sperm could be obtained from males through non-lethal biopsies. At present, large-scale aquaculture production for reintroduction, restocking or stock enhancement purposes is neither possible nor an advisable conservation tool yet. Further study is required and meanwhile, an appropriate design of a network of effectively protected marine areas that ensures connectivity among extant populations is necessary.info:eu-repo/semantics/publishedVersio

The application of diode laser in the treatment of oral soft tissues lesions. A literature review

Since its appearance in the dental area, the laser has become a treatment of choice in the removal of lesions in the oral soft tissues, due to the numerous advantages they offer, being one of the most used currently the diode laser. The aim of this review was to determine the efficacy and predictability of diode laser as a treatment of soft tissue injuries compared to other surgical methods. A literature review of articles published in PubMed/MEDLINE, Scopus and the Cochrane Library databases between 2007 and 2017 was performed. ?Diode laser?, ?soft tissue?, ?oral cavity? and ?oral surgery? were employed for the search strategy. Only articles published English or Spanish were selected. The diode laser is a minimally invasive technology that offers great advantages, superior to those of the conventional scalpel, such as reduction of bleeding, inflammation and the lower probability of scars. Its effectiveness is comparable to that of other types of lasers, in addition to being an option of lower cost and greater ease of use. Its application in the soft tissues has been evaluated, being a safe and effective method for the excision of lesions like fibromas, epulis fissuratum and the accomplishment of frenectomies. The diode laser can be used with very good results for the removal of lesions in soft tissues, being used in small exophytic lesions due to their easy application, adequate coagulation, no need to suture and the slightest inflammation and pain

The controllability of a monetary aggregate in EMU

La consideracion de un agregado monetario como objetivo intermedio de la politica monetaria exige que esa definicion de liquidez mantenga una relacion de estabilidad con el objetivo final y que su evolucion pueda ser controlada por parte del banco central. Este documento analiza esta segunda cuestion, centrandose en las posibilidades que tendria el Banco Central Europeo de controlar efectivamente un agregado monetario si decidiera considerarlo como objetivo intermedio. En el trabajo se revisan los mecanismos a traves de los cuales la politica monetaria puede controlar la evolucion de la cantidad de dinero, y se examinan las propiedades empiricas de la demanda de dinero en la Union Monetaria Europea (UME) y en un pais, como Alemania, en el que se han venido fijando objetivos en terminos de un agregado monetario. El documento pone de manifiesto que las condiciones para ejercer un control adecuado de la cantidad de dinero en la UME son notablemente mas desfavorables de lo que resultan en Alemania. (ac) (jle) (em) (jp) (mac