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941.
Jos María Fuentes Pardo Ignacio Caas Guerrero 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2006,21(5):475-484
From the dawn of civilization, human beings have exploited the underground space provided by natural or excavated caves for the purpose of habitation and as storage space for different agricultural produce.Throughout the Mediterranean countryside, and particularly in many rural areas of the Iberian Peninsula, an ancestral example of that underground architecture survives through the ages: the subterranean wine cellars. These human-excavated caves, originally devoted to the winemaking and vintage processes, are placed near the villages in groups of several tens of constructions, giving rise to outstanding visual landscapes.This paper is concerned with the formal and functional features of this vernacular subterranean architecture. By a research carried out in one of the most traditional winemaking regions of Spain – Ribera de Duero – the characteristics, excavation techniques and typological classification of the caves are discussed. Moreover, the problem caused by the obsolescence and consequent dereliction of these subterranean constructions is shown here and several alternative uses are examined to preserve this underground heritage. 相似文献
942.
On the basis of a recent work proposed by the authors on a double-minimization method for evaluating inter-element forces and stresses transmitted across mesh lines, the crack opening conditions at a corner node of the FE mesh, from where several lines (potential cracks) emanate, is examined in this paper. The study is developed locally as a post-processing step of a standard displacement-based FE calculation, in terms of an always-increasing external (macroscopic) load factor μ. The cracking laws for each potential crack line are assumed rigid-plastic with hyperbolic failure criterion in terms of normal and shear components of the stress traction at that point. It is observed that, as μ increases, in general such point may undergo up to four phases of evolution until a crack can effectively open through it. First, while stress tractions across mesh lines at the point are all below cracking criterion, forces may be evaluated with the double minimization method recently proposed. Second, cracking criterion is reached for one of the lines only. Stress evaluation requires a modified minimization method with one (hyperbolic) constraint; however, crack still does not open at the node because of the lack of kinematic continuity. Third, cracking criterion is satisfied for a second of the lines converging at the nodal point. Stress tractions may then be calculated with a system of equations involving the two hyperbolic constraints alone and no minimization is needed. But in general the through crack cannot open yet at this stage because of non-coincident flow rules, until either (i) a third line reaches the cracking criterion, or (ii) these get reoriented to exhibit parallel directions in the global reference system. Two simple examples of application are provided which illustrates the development of the various cracking stages and shows different situations that may take place. 相似文献
943.
944.
Redolar-Ripoll Diego; Soriano-Mas Carles; Guillazo-Blanch Gemma; Aldavert-Vera Laura; Segura-Torres Pilar; Morgado-Bernal Ignacio 《Canadian Metallurgical Quarterly》2003,117(2):246
To evaluate whether intracranial self-stimulation (SS) ameliorates conditioning deficits induced by parafascicular nucleus (PF) damage in young and aged rats, the authors gave rats a daily session of 2-way active avoidance until a fixed criterion was achieved. Four experimental groups were established in both young and aged rats: SS treatment after every conditioning session (SS groups), pretraining PF lesions (lesion groups), PF lesions and SS treatment (L + SS groups), and controls. SS treatment not only canceled the detrimental effects of PF lesions, but also improved conditioning in lesioned rats (L + SS groups). This effect was more powerful in aged rats. SS treatment compensated for memory deficits generated by hypofunctionality of arousal systems such as that involving the PF. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
945.
No Heading An alternative density functional for studying adsorption of 4He onto solid surfaces is suggested, where the helium-helium interaction is screened at small distances by the two-body distribution function g(r) and the gradient-gradient term of the Orsay-Trento proposal is replaced by a contribution written in terms of the gradient of g(r). Results for helium adsorption onto planar Na substrates are reported.PACS numbers: 67.40.Db, 67.70.+n, 68.10.–m, 68.15.+e 相似文献
946.
Validation of a 1D-2D dual drainage model under unsteady part-full and surcharged sewer conditions 总被引:1,自引:0,他引:1
This paper presents a 1D-2D dual drainage model to compute the rainfall-runoff transformation in urban environments. Overland flow in major drainage systems is modelled with the 2D shallow water equations, whereas the flow in a sewer network is computed with the 1D Saint-Venant equations using the two-component pressure approach to model pressure-flow conditions. The surface and sewer network models are linked through manholes, which allow water interchange in both directions. A new series of rainfall–runoff experiments in a real-scale physical model of a street section is used to validate the model under unsteady part-full and pressure flow conditions. The experimental measurements of water depth and discharge at several locations in a drainage network show a very satisfactory performance of the numerical model. 相似文献
947.
Phase separation and segregation morphology of PCL/PS blends: Quantitative effect of the crystallization temperature,composition, and molecular weight of PS
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Leonel Ignacio Silva Úrsula María Montoya Rojo Carmen Cristina Riccardi 《Polymer Engineering and Science》2017,57(10):1062-1072
The phase diagrams for blends of semicrystalline poly(ε‐caprolactone) (PCL) with amorphous polystyrene (PS) were determined and it was noticed that when molecular weight increases, the critical composition diminishes while its temperature increases. That is the same effect that produces the increase in the polydispersity of PS. From the fitting of phase diagrams of blends of PCL with oligomers and homopolymers of PS, taking into account the polydispersity, it was possible to conclude that the miscibility in these systems is due only by entropic effects. The crystalline fraction as well as the interlamellar spacing increased with crystallization temperature while the volume fraction of the amorphous PCL in the interfibrillar regions increases for the pure PCL and in its blends with low concentration of PS. Increasing the mass fraction of PS increases the average long spacing (L) till a weight fraction of 60%, for higher mass fractions L is almost constant indicating the interfibrillar segregation of PS. The PCL lamellar morphology is not affected when the molecular weight of PS employed is similar or higher than the molecular weight of PCL. If the PS has a higher molecular weight its penetration into the structure is inhibited. POLYM. ENG. SCI., 57:1062–1072, 2017. © 2016 Society of Plastics Engineers 相似文献
948.
Castro-Hermida JA García-Presedo I Almeida A González-Warleta M Correia Da Costa JM Mezo M 《The Science of the total environment》2008,405(1-3):45-53
To evaluate the presence of Cryptosporidium spp. and Giardia duodenalis in the influent and final effluent of sixteen drinking water treatment plants located in a hydrographic basin in Galicia (NW Spain) - in which the principal river is recognised as a Site of Community Importance (SCI) - estimate the efficiency of treatment plants in removing these protozoans and determine the species and genotypes of the parasites by means of a molecular assay. All plant samples of influent and final effluent (50-100 l) were examined in the spring, summer, autumn and winter of 2007. A total of 128 samples were analysed by method 1623, developed by US Environmental Protection Agency for isolation and detection of both parasites. To identify the genotypes present the following genes were amplified and sequenced: 18S SSU rRNA (Cryptosporidium spp.) and b-giardina (G. duodenalis). The mean concentrations of parasites in the influent were 0.0-10.5 Cryptosporidium spp. oocysts per litre and 1.0-12.8 of G. duodenalis cysts per litre. In the final treated effluent, the mean concentration of parasites ranged from 0.0-3.0 oocysts per litre and 0.5-4.0 cysts per litre. The distribution of results by season revealed that in all plants, the highest numbers of (oo)cysts were recorded in spring and summer. Cryptosporidium parvum, C. andersoni, C. hominis and assemblages A-I, A-II, E of G. duodenalis were detected. Cryptosporidium spp. and G. duodenalis were consistently found at high concentrations in drinking water destined for human and animal consumption in the hydrographic basin under study, in Galicia (NW Spain). It is important that drinking water treatment authorities rethink the relevance of contamination levels of both parasites in drinking water and develop adequate countermeasures. 相似文献
949.
Yolanda Ubago Martínez Ignacio García-Lautre Belén Iraizoz Pedro Pascual 《Papers in Regional Science》2019,98(6):2211-2231
Which of a region's characteristics most strongly influence its degree of resilience? This study constructs a composite resilience index for the Spanish regions and uses Multiple Factor Analysis to compare it with the Martin resilience index (Martin, 2012). The results of a Principal Components Analysis to measure the relative contributions of potential regional resilience drivers indicate that, during recovery periods, it is market- service focused regional economies that show stronger resilience, while, in crisis periods, it is regions with a more highly-educated workforce. 相似文献
950.
Lucia M. Balsa Dr. Maria R. Rodriguez Prof. Beatriz S. Parajón-Costa Prof. Ana C. González-Baró Prof. Martin J. Lavecchia Prof. Ignacio E. León 《ChemMedChem》2022,17(4):e202100520
The purpose of this work was to screen the anticancer activity and mechanisms of action of Cu(II)-acylhydrazone complex [Cu(HL)(H2O)](NO3)⋅H2O, (CuHL), to find a potential novel agent for breast chemotherapies. Cytotoxicity studies on MCF7 cells demonstrated that CuHL has stronger anticancer properties than cisplatin over breast cancer cell models. Computational simulations showed that CuHL could interact in the minor groove of the DNA dodecamer, inducing a significant genotoxic effect on both cancer cells from 0.5 to 1 μM. In this sense, molecular docking and molecular dynamics simulations showed that the compound could interact with 20S proteasome subunits. Also, cell proteasome experiments using breast cancer cells revealed that the complex can inhibit proteasomal activity. Moreover, CuHL induced apoptosis in breast cancer cells at very low micromolar concentrations (0.5–2.5 μM) and displayed relevant anticancer activity over spheroids derived from MCF7 cells. Ultimately, CuHL diminished the number of mammospheres formed, disturbing their morphology and size. 相似文献