1,508 research outputs found

    Diálogos sobre la catedral de Plasencia

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    SIAM. Series Iberoamericanas de Museología. Año 3, Vol.

    Modellazione agli elementi discreti di prove di punzonamento di una rete corticale doppio torta a maglia esagonale

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    Le reti metalliche sono comunemente usate per la protezione su pendio e la prevenzione del rischio di crolli e distacchi. La loro progettazione \ue8 principalmente basata su considerazioni di carattere empirico, legate all\u2019esperienza del progettista; data l\u2019importanza di tali interventi, e al fine di ottimizzare il progetto, stanno entrando in uso nuovi metodi numerici. In questo lavoro verr\ue0 impiegato il metodo agli elementi discreti (DEM), particolarmente adatto per lo studio di problemi a grande deformazioni, fino alla rottura degli elementi. L\u2019obiettivo \ue8 quello di validare un modello di rete doppio torta a maglia esagonale durante una prova di punzonamento attraverso il raffronto con i risultati sperimentali. In particolare verranno analizzati tre diversi modelli costitutivi e l\u2019influenza delle curve tensione-deformazione relative al filo singolo e a quello doppio torto

    Towards a Hybrid Design Approach of Anchored Drapery Systems

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    Anchored drapery meshes represent a worldwide adopted protective solution against rockfall. The mechanical performance of a wire mesh is evaluated through laboratory procedures in which the boundary conditions strongly differ from the ones typical of field applications. This shows that the laboratory characterization is, in general, not representative of the field behavior. In this work, referring to a double-twisted wire mesh, a simple approach allowing the extension of the laboratory characteristic values to field conditions is proposed. The approach is based on the definition of analytical relations for evaluating the effects of both the mesh’s system geometry and the loading condition on the force–displacement response. These relations are derived from previously calibrated laboratory tests and are extended to different configurations on the basis of a large number of discrete element simulations. A master curve allowing the prediction of the entire force–displacement response of a general configuration of the drapery system is then defined. The results of this study can provide useful information for designing anchored drapery systems and can be easily associated with standard limit equilibrium calculations to move toward a hybrid design approach that couples forces with mesh deformations

    Gestión de colecciones del Museo del Hidalgo

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    SIAM. Series Iberoamericanas de Museología. Año 3, Vol.

    Stunning pigs with different gas mixtures : Aversion in pigs

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    The objective of this study was to assess the aversion to exposure of 90% argon, 70% N2/30% CO2 and 85% N2/15% CO 2 by volume in atmospheric air in 24 halothane-free slaughter-weight pigs using aversion learning techniques and behavioural studies in an experimental slaughterhouse. Pigs were subjected to the treatments individually during 2 separate trials of 12 animals each. The time of exposure to the gases was 46 and 32 s, respectively. When the pit contained any of the 3 gas mixtures, the time taken to cross the raceway and enter the cradle (TCREC) increased compared with the training sessions (atmospheric air). The incidence of pigs showing retreat and escape attempts and gasps and the number of times that this behaviour was performed was lower in 90% argon than in the gas mixtures with N2 and CO2. On the other hand, the time to loss of posture was lower with 70% N2/30% CO2 than with argon. The second exposure to all gas mixtures was more aversive than the first and the loss of posture also occurred earlier in the second exposure. In conclusion, pigs showed more aversion to gas mixtures with N2 and either 15% or 30% CO 2 by volume than 90% argon by volume

    Managing with (fluorescent)-biomimetic dendrimers

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    Dendrimers that are modified through their peripheral groups have been employed for many biomedical purposes. Diagnosis via specific interactions with target proteins is one of the objectives that has been given more attention. In this way, we have been developing different methodologies for the detection of immunoglobulins, as an in vitro method for the diagnosis of allergic reactions to drugs [1], [2]. Specific cell interactions of surfaces grafted dendrimers have been applied to the study of cell adhesion. We have studied also the application of dendrimer-based uneven nanopatterns to evaluate the local RGD surface density effects on cell adhesion, as bioactive substrates to evaluate the impact of the RGD local surface density on the chondrogenic induction of adult human mesenchymal stem cells [3], [4], [5]. Although the use of PAMAM dendrimer has allowed us to develop useful methods for this purpose, for certain objectives we have required the development of new dendrimeric models. We have developed a new approach for the production of allaliphatic polyamide dendrimers (BAPAD) by iterative 3,3′-diaminopivalic acid connections as building blocks for dendrimer construction. These dendrimers were studied in explicit solvent by atomistic forcefield-based molecular dynamics to characterize structural properties such as shape, radius and monomer distribution [6]. Fluorescent labeling of these biomimetic dendrimers has been used as a tool to study their interaction with cells.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Animal Welfare and Meat Quality Assessment in Gas Stunning during Commercial Slaughter of Pigs Using Hypercapnic-Hypoxia (20% CO2 2% O-2) Compared to Acute Hypercapnia (90% CO2 in Air)

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    Simple Summary Animals must be stunned before slaughter to avoid fear, pain, and distress. In pigs, the most extensively used method is exposure to hypercapnia (high (>80%) concentrations of carbon dioxide (CO2)). However, it produces irritation of the mucosa and a sense of breathlessness, reducing the welfare before slaughter. We investigated whether using hypercapnic-hypoxia (20% CO2 and less than 2% O-2) reduced aversion and discomfort compared to hypercapnia, and whether the quality of the stunning was adequate, meaning that no animals regain conscious after stunning. Moreover, we compared the impact of both stunning gases for meat and carcass quality. Our results suggest that both gases provoked aversion and discomfort, but these were lower in pigs stunned with the N-2 mixture compared to high CO2. On the other hand, the stun quality of the N-2 mixture was poorer than high CO2 stunning, given that more animals regained consciousness before sticking with the N-2 gas mixture. The stunning quality of the N-2 mixture, however, was improved when oxygen concentration was below 2%. Meat quality was slightly poorer in N-2 stunning compared to high CO2, with a higher percentage of carcasses showing pale, soft, and exudative pork.This study assessed aversion, stunning effectiveness, and product quality of nitrogen and carbon dioxide (CO2) mixtures used for stunning pigs. A total of 1852 slaughter pigs divided into two similar batches was assessed during routine slaughter in a Swedish commercial abattoir using either hypercapnic-hypoxia (20% CO2 and less than 2% O-2; 20C2O) or hypercapnia (90% CO2; 90C) gas mixtures. Behavioral indicators of aversion and discomfort were recorded. After exposure, the stunning quality was assessed through brainstem reflexes. After slaughter, the pH and electric conductivity of carcasses were assessed to estimate the incidence of pale, soft, and exudative (PSE) pork, and the presence of ecchymosis were inspected. Compared to 90C, pigs exposed to 20C2O showed a later (p < 0.05) onset of behaviors indicative of aversion, and a lower (p < 0.01) incidence of breathlessness. However, unconsciousness (i.e., losing posture) appeared earlier (p < 0.01) in 90C compared to 20C2O. In 90C, all (100%) pigs were adequately stunned, whereas in 20C2O a 7.4% of pigs showed signs of poor stunning, especially when oxygen concentrations were >2% (p < 0.001). The percentage of PSE carcasses was higher (p < 0.01) in 20C2O than 90C. In conclusion, compared to 90C, 20C2O reduced aversion and discomfort but showed lower stun effectiveness, especially when O-2 was above 2%, and a slightly poorer pork quality

    Analysis of Sport Supplement Consumption and Body Composition in Spanish Elite Rowers.

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    The aim of this study was to analyze the anthropometric characteristics and sport supplement (SS) consumption patterns of heavyweight and lightweight international rowers. Methods: The 13 heavyweights (11 males) and seven lightweights (five males) of the Spanish National Rowing Team were recruited for the study. Body composition was measured by bio-impedance analysis, and the questionnaire used in this investigation was previously validated to assess SS consumption. According to anthropometrics parameters, it was reported that male heavyweight rowers were heavier (p < 0.001) and taller (p < 0.001), but no statistical di erences were reported for % body fat (p = 0.104) or % lean body mass (p = 0.161). All rowers reported consumption of at least one SS. Based on the Australian Institute of Sport’s classification, higher medical supplement consumption was observed when comparing heavyweight rowers to lightweight rowers (2.5 1.1 vs. 1.7 0.5, p = 0.040). There were no di erences in the totals of group A (strong scientific evidence for sports scenarios, p = 0.069), group B (emerging scientific support, deserving of further research, p = 0.776), or group C (scientific evidence not supportive of benefit and/or security amongst athletes, p = 0.484). The six most consumed SSs were iron (85%), ca eine (85%), -alanine (85%), energy bars (85%), vitamin supplements (80%), and isotonic drinks (80%), with no statistical di erences between heavyweight and lightweight rowers (p > 0.05). These results suggest that the absence of di erences in body composition (expressed as a percentage) do not represent anthropometric disadvantages for heavyweight rowers. In addition, SS consumption was similar between rowers, reporting only higher medical supplement consumption in heavyweight rowers.post-print931 K

    Theoretical investigation of lattice thermal conductivity and electrophononic effects in SrTiO3

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    We present a theoretical study of the lattice thermal conductivity of SrTiO 3 in its antiferrodistortive ferroelastic phase and of its dependence on an applied external electric field, via electrophononic couplings. The calculations are done by using second-principles density-functional theory and the full solution of the Boltzmann transport equation. Our results allow, on one hand, to identify and explain deviations from the usual temperature dependence of the thermal conductivity, revealing Poiseuille flow and a rare umklapp transport regime, in agreement with recent experimental results [Martelli et al., Phys. Rev. Lett. 120, 125901 (2018)]; on the other hand, they show that an external electric field, by reducing the symmetry of the lattice, activates different phonon-phonon scattering processes and thus yields a reduction of the thermal conductivity, supporting the generality of a heat control strategy previously reported by some of us [Seijas-Bellido et al., Phys. Rev. B 97, 184306 (2018)]Peer reviewe
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