1,633 research outputs found

    METHODOLOGICAL APPROACH TO INTEGRATE A GIS-BASED ANALYSIS INTO THE DESIGN OF CULTURAL ITINERARIES IN THE FRAMEWORK OF AN INTEGRATED PLAN FOR TERRITORY

    Get PDF
    Abstract. The historical concept of heritage, which mostly comprised physical architectural and archaeological evidences, has been extended to the surrounding landscape in the last decades. This tendency has been corroborated by a series of International Charters and the European Landscape Convention of 2000. Landscape, understood as the perceptible part of territory that supports the contingencies throughout history, is subject to protection, management and planning. However, some inherent aspects of territory have been disregarded because of the frantic enlargement of cities throughout the twentieth century at the expense of the rural areas. Territorial heritage, which is fundamental to cultural landscape formation, is currently considered a strategic resource able to guarantee self-sustaining development of peri-urban and rural zones. In many cases, urban investments and planning associated to the enlargement of the metropolitan areas have overlooked this fruitful territorial heritage, making cultural landscapes illegible. This is the case of the cultural landscapes in the buffer zones of the archaeological sites, which are part of a diffuse territorial heritage that requires to be assessed by means of some innovative approaches. Cultural itineraries are presented as a landscape architecture strategy for valorising territorial heritage. Well-targeted design of these itineraries can also contribute to restore the dynamics of cultural landscape formation and to regenerate peri-urban and rural areas by promoting its self-sustaining development. To that end, the conceptualisation and hypotheses posed by some authors of the SocietĂ  dei Territorialisti/e are used as references. A work methodology to design cultural itineraries is suggested in line with the presumptions of an integrated plan for territory aimed to valorise the territorial heritage. This paper explores in which way a GIS-based analysis can be integrated into the design of a landscape architecture like the cultural itinerary

    Enhanced Parallel Generation of Tree Structures for the Recognition of 3D Images

    Get PDF
    Segmentations of a digital object based on a connectivity criterion at n-xel or sub-n-xel level are useful tools in image topological analysis and recognition. Working with cell complex analogous of digital objects, an example of this kind of segmentation is that obtained from the combinatorial representation so called Homological Spanning Forest (HSF, for short) which, informally, classifies the cells of the complex as belonging to regions containing the maximal number of cells sharing the same homological (algebraic homology with coefficient in a field) information. We design here a parallel method for computing a HSF (using homology with coefficients in Z/2Z) of a 3D digital object. If this object is included in a 3D image of m1 × m2 × m3 voxels, its theoretical time complexity order is near O(log(m1 + m2 + m3)), under the assumption that a processing element is available for each voxel. A prototype implementation validating our results has been written and several synthetic, random and medical tridimensional images have been used for testing. The experiments allow us to assert that the number of iterations in which the homological information is found varies only to a small extent from the theoretical computational time.Ministerio de Economía y Competitividad MTM2016-81030-

    Tribological behavior of electric vehicle transmission oils using Al2O3 nanoadditives

    Get PDF
    Antifriction and antiwear performances of Al2O3 nanoparticles (NPs) as additives of an automatic transmission fluid, ATF, are presented in this research. For this purpose, four nanodispersions were formulated: ATF + 0.05 wt% Al2O3 NPs, ATF + 0.10 wt% Al2O3 NPs, ATF + 0.15 wt% Al2O3 NPs and ATF + 0.20 wt% Al2O3 NPs to identify the optimal concentration of additive. Tribological experiments were taken at pure sliding conditions, with the formulated nanolubricants and the ATF, under a working load of 20 N. The four nanolubricants tested resulted in lower friction coefficients than those obtained using ATF, reaching a maximum reduction of 6 % with the ATF + 0.10 wt% Al2O3 nanolubricant. The tribological pairs tested with the Al2O3 nanolubricants show lower wear than those tested with the ATF, having the best wear decrease with the ATF + 0.10 wt% Al2O3 nanolubricant, with reductions of 45, 57 and 78 %, respectively, in diameter, depth and area of the wear scar. Furthermore, by means of confocal Raman microscopy, roughness evaluation and SEM-EDX of the worn tribological specimens, it can be determined that mending, tribo-sintering as well as rolling mechanisms occur.This research is supported by Xunta de Galicia (ED431C 2020/10) and by MCIN/AEI/10.13039/501100011033 through the PID2020-112846RB-C22 project. JMLdR is grateful for financial support through the Margarita Salas program, funded by MCIN/AEI/10.13039/501100011033 and “NextGenerationEU/PRTR”. Furthermore, authors are also grateful to Repsol Lubricants for providing the ATF and to RIAIDT-USC for its analytical facilities.S

    Acute and long-lasting effects of oxytocin in cortico-limbic circuits: consequences for fear recall and extinction.

    Get PDF
    The extinction of conditioned fear responses entrains the formation of safe new memories to decrease those behavioral responses. The knowledge in neuronal mechanisms of extinction is fundamental in the treatment of anxiety and fear disorders. Interestingly, the use of pharmacological compounds that reduce anxiety and fear has been shown as a potent co-adjuvant in extinction therapy. However, the efficiency and mechanisms by which pharmacological compounds promote extinction of fear memories remains still largely unknown and would benefit from a validation based on functional neuronal circuits, and the neurotransmitters that modulate them. From this perspective, oxytocin receptor signaling, which has been shown in cortical and limbic areas to modulate numerous functions (Eliava et al. Neuron 89(6):1291-1304, 2016), among them fear and anxiety circuits, and to enhance the salience of social stimuli (Stoop Neuron 76(1):142-59, 2012), may offer an interesting perspective. Experiments in animals and humans suggest that oxytocin could be a promising pharmacological agent at adjusting memory consolidation to boost fear extinction. Additionally, it is possible that long-term changes in endogenous oxytocin signaling can also play a role in reducing expression of fear at different brain targets. In this review, we summarize the effects reported for oxytocin in cortico-limbic circuits and on fear behavior that are of relevance for the modulation and potential extinction of fear memories

    Tribological properties of graphene nanoplatelets or boron nitride nanoparticles as additives of a polyalphaolefin base oil

    Get PDF
    In this work, antifriction and antiwear capabilities of hexagonal boron nitride nanoparticles (h-BN) or graphene nanoplatelets (GnP) as additives of a polyalphaolefin neat oil (PAO 40) were studied at pure sliding conditions. For this purpose, eight PAO 40 nanodispersions were prepared: four nanodispersions with h-BN and four others based on GnP. The mass concentrations of these dispersions are 0.25, 0.50, 0.75 and 1.00 wt% of h-BN and 0.05, 0.10. 0.25 and 0.50 wt% of GnP, having all of them a good stability against sedimentation (at least 96 h). Tribological assays were carried with prepared nanolubricants as well as with PAO 40 base oil at 20 N load. All nanolubricants based on h-BN or GnP showed lower friction coefficients in comparison to the non-additivated neat oil, with a maximum decrease in friction of 21% for the 0.50 wt% GnP nanodispersion. Regarding the produced wear, all disks lubricated with nanolubricants showed lower wear than those lubricated using PAO 40. The greatest wear reduction in wear track width (22%) was also achieved for the 0.50 wt% in GnP nanolubricant. Moreover, through the confocal Raman microscopy and roughness analyses of worn disks it can be concluded that the wear reductions are due to the surface repairing and tribofilm formation mechanismsS

    Tuning Proton Conductivity Properties of Lanthanide Amino-Sulfophosphonates-Loaded Nafion Composite Membranes

    Get PDF
    Polymer-based electrolytes in proton exchange membrane fuel cells (PEMFCs) utilize acidic groups as proton carriers and hydrogen bonding networks as proton-conducting pathways to facilitate proton transport. Crystalline acid-functionalized metal phosphonates are potential proton conductors while maintaining a high hydration degree below 100 °C. This property may be combined with Nafion-like polymers which tend to dehydrate at the operating conditions of PEMFCs [1,2]. In this work, preliminary results of the preparation of lanthanide amino-sulfophosphonates-loaded Nafion composites membranes and the corresponding electrical properties are reported. Synthesis conditions of lanthanide derivatives were optimized following a hightrough-put screening at 140 °C. Their crystal structures, solved from synchrotron X-ray powder diffraction data, corresponds to layered frameworks where the acidic groups, -CPO3H or -SO3H, point toward the interlamellar region interacting by H-bond with the lattice water. The composites were prepared by mixing the metal phosphonates with Nafion solution at different loadings. The membranes were characterized by SEM, XRD and FT-IR. A study of the proton conductivity as a function of the composite membranes was carried out at 90 °C and 95% RH. Referencias [1] Y. Gao, R. Broersen, W. Hageman, N. Yan, M. C. Mittelmeijer-Hazeleger, G. Rothenberg, S. Tanase. J. Mater. Chem. A, 2015, 3, 22347–22352. [2] A. Cabeza, P. Olivera-Pastor, R. M. P. Colodrero. Tailored Organic-Inorganic Materials, Brunet, E., Colón, J.L., Clearfield, A., Eds.; John Wiley & Sons, Inc. 2015; Ch. 4, 137−191.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
    • 

    corecore