214 research outputs found

    España desde Europa: percepciones y relaciones (1982-2004)

    Get PDF
    En este trabajo se estudia la relación entre España y las políticas europeas en el periodo 1982- 2004, utilizando como enfoque la historia de las relaciones internacionales. En el periodo examinado aquí, el sistema internacional se caracterizó por grandes cambios, pasando de la "segunda guerra fría" de los años ochenta a las nuevas dinámicas de la posguerra fría en los años noventa y luego en 2001-2003; cambios que han involucrado a Europa en general (transición de la CEE a la UE, políticas de ampliación, proyecto Euro-Med, UEM, etc.) y a España en particular. La trayectoria histórica de la relación entre España y Europa es analizada en esa compleja fase de transformación del sistema internacional. Las percepciones que los europeos han tenido de España también se examinan con respecto a los diferentes Gobiernos que se sucedieron en Madrid desde el periodo de transición hasta 2004. Se dedica atención a los principales protagonistas de los eventos analizados, en particular por su papel en la política internacional

    Machine learning-based automatic operational modal analysis: A structural health monitoring application to masonry arch bridges

    Get PDF
    Structural health monitoring (SHM) is one of the main research topics in civil, mechanical and aerospace engineering. In this regard, modal parameters and their trends over time can be used as features and indicators of damage occurrence and growth. However, for practical reasons, output-only techniques are particularly suitable for the system identification (SI) of large civil structures and infrastructures, as they do not require a controlled source of input force. In this context, these approaches are typically referred to as operational modal analysis (OMA) techniques. However, the interpretation of the OMA identifications is a labour-intensive task, which could be better automated with artificial intelligence and machine learning (ML) techniques. In particular, clustering and cluster analysis can be used to group unlabelled datasets and interpret them. In this study, a novel multi-stage clustering algorithm for automatic OMA (AOMA) is tested and validated for SHM applications-specifically, for damage detection and severity assessment-to a masonry arch bridge. The experimental case study involves a 1:2 scaled model, progressively damaged to simulate foundation scouring at the central pier

    A Hazardous Area Personal Monitoring System for Operators in Gas Depots and Storage Tanks

    Get PDF
    This work describes a smart monitoring system for the detection of flammable gas residues, toxic gases, and reduced oxygen concentrations. The proposed system aims at reducing the risk of fires and explosions, thus increasing the safety of workers engaged in maintenance or inspection of gas storages. The monitoring system is based on compact battery-powered wearable sensor nodes containing sensors for LPG flammable compounds, toxic gases, and oxygen. The designed system can also increase plants safety by incorporating an intrusion detection system, which prevents unauthorized access to safety-critical areas to prevent accidents. The sensor nodes transmit data through a LoRa low power radio channel to a remote server whereas they allow for the identification of the operators for the access to restricted areas exploiting a Bluetooth Low Energy (BLE) proximity technique

    Optimization of perovskite gas sensor performance: characterization, measurement and experimental design

    Get PDF
    Eight different types of nanostructured perovskites based on YCoO3 with different chemical compositions are prepared as gas sensor materials, and they are studied with two target gases NO2 and CO. Moreover, a statistical approach is adopted to optimize their performance. The innovative contribution is carried out through a split-plot design planning and modeling, also involving random effects, for studying Metal Oxide Semiconductors (MOX) sensors in a robust design context. The statistical results prove the validity of the proposed approach; in fact, for each material type, the variation of the electrical resistance achieves a satisfactory optimized value conditional to the working temperature and by controlling for the gas concentration variability. Just to mention some results, the sensing material YCo0.9Pd0.1O3 (Mt1) achieved excellent solutions during the optimization procedure. In particular, Mt1 resulted in being useful and feasible for the detection of both gases, with optimal response equal to +10.23% and working temperature at 312°C for CO (284 ppm, from design) and response equal to −14.17% at 185°C for NO2 (16 ppm, from design). Analogously, for NO2 (16 ppm, from design), the material type YCo0.9O2.85 + 1%Pd (Mt8) allows for optimizing the response value at −15.39% with a working temperature at 181.0°C, whereas for YCo0.95Pd0.05O3 (Mt3), the best response value is achieved at −15.40% with the temperature equal to 204°C

    On the safety design of radar based railway level crossing surveillance systems

    Get PDF
    Recent accidents experienced at railway level crossings are pushing researchers to design surveillance systems able to grant safety of passengers and structural integrity of trains at level crossings. The challenge is represented by granting at the same time an appropriate reliability, availability and maintainability degree despite the high safety requirements imposed by the application. The approach proposed in this paper takes into consideration the most common suggested standards used in designing this kind of systems and introduces new general concepts which demystify the use of such standards in actual applications. This paper illustrates the roadmap to be followed in general when designing level crossing monitoring systems, to minimize the risk due to object misdetection occurring on barrier closure when exploiting radar technology

    Is the Thoracolumbar Injury Severity Score (TLISS) still a good base for the education of residents in Orthopaedics and Traumatology?

    Get PDF
    ABSTRACT Introduction. Thoracolumbar spinal injuries indicated for surgical intervention specify the necessity of intervention within 24 hours. The traumatologists working in a structure without a Spinal Unit must be able to evaluate such injury and set indications for surgical treatment, that is, nonoperative treatment. The purpose of this study is to evaluate if Thoracolumbar Injury Severity Score (TLISS) is still a good base for the classification of thoracolumbar spinal injuries and to give a correct indication for nonoperative, that is, surgical treatment. Patients and Methods. Six Orthopaedics and Traumatology residents from Siena (Italy), five Orthopaedics and Traumatology residents from the Clinical Centre of Banja Luka (Bosnia and Herzegovina) and five Orthopaedics and Traumatology residents from the Alta Val d’Elsa Hospital, Siena (Italy) were presented 24 clinical cases from professional literature where the following data were indicated: patient’s age, neurological conditions, description of the injury, mechanism of the injury and radiological findings (RTG, MR). The abovementioned 24 patients were chosen from the literature based on the injuries mostly seen by an orthopaedist with a lack of experience in the problems of spinal column trauma (low energy trauma, with partial or without neurological impairments, with the TLISS score of 4). The residents from the three groups had to classify all patients according to the TLISS score and to define the most appropriate method of treatment-conservative or surgical, and after that, all classifications, as well as the therapeutic decisions, were compared. The statistical methods used in this study include: statistical significance, reliability (P<0.05), the validity of the decision, the percentage of accuracy and Cohen’s kappa coefficient. The best results in evaluation of the mechanism of the injury were demonstrated by the group of doctors from the Orthopaedic Hospital with an accuracy of 78.8% (P<0.05) and with an average correlation (K = 0.598). The best description of the injury was presented by the doctors from Siena with 87% accuracy (P<0.05) and with correlation (K=0.749). The doctors from Siena responded best at evaluating the neurological status with 97.6% accuracy (P<0.05) and with correlation (K=0.936). The assessment of the injury of the PCL residents from Siena was 64.7% accurate (P<0.05) with correlation (K=0.426). The total TLISS score was best calculated by the residents of Siena with 82% accuracy (P<0.05) and correlation (K=0.718). The most appropriate therapeutic decision was made by the residents from Siena with 80.3% accuracy (P<0.05) and with correlation (K =0.707). Conclusion. Currently, the Denis classification and the AO classification are the most widely used classification algorithms for the fractures of thoracolumbar spine but some defects have also been identified in both of them. The value of TLISS evaluation is by the three groups of residents in presented 24 patients from the professional literature. Significant differences in accuracy were found in defining a real damage of the spinal cord at the level of the cauda equina. The evaluation of the integrity of the posterior longitudinal ligament by the radiography is of low accuracy

    Treatment of canine leishmaniasis: Long term molecular and serological observations

    Get PDF
    The aim of the present paper was to evaluate the anti-Leishmania activity of 3 different protocols of treatment (miltefosine plus allopurinol, difloxacin cloridrate plus metronidazole and meglumine antimoniate plus allopurinol) in 42 dogs naturally infected by L. infantum, during a 24-months parasitological and clinical follow-up. Our results suggest that, apart from miltefosine, the other two therapeutic regimens could be evaluated to treat animals with canL in medium-endemicity areas

    Strong mortars from the tower of the Cerreto Ciampoli castle (Siena, Italy)

    Get PDF
    [EN] Known since the eleventh century, the castle of Cerreto Ciampoli was one of the main fortifications of the ancient Republic of Siena (Tuscany, Italy). The magnificent ruins, located on the top of a hill overlooking the Chianti Mountains, consist of two city walls, a door, a church, the remains of some rooms and a mighty tower lying on the ground broken up into five sections of several meters in length. The present study is focused on the analysis of the mineralogical-petrographic and chemical features of the sack and the bedding mortars of the tower, and it is aimed at understanding the exceptional qualities of these mortars that, during the collapse of the artifact, prevented the tower from shattering into smaller pieces. The tenacity of these mortars appears to be the result of the concurrence of more expedients, such as the choice of well-selected materials (hydraulic limes obtained from the local Alberese limestone, sandy aggregates from well-rinsed river sands with a high silicoclastic component) and the use of particular technical methods (i.e. hot lime technique).Giamello, M.; Columbu, S.; Gabbrielli, F.; Mugnaini, S.; Scala, A. (2020). Le tenaci malte della torre del castello di Cerreto Ciampoli (Siena, Italia). Editorial Universitat Politècnica de València. 1509-1516. https://doi.org/10.4995/FORTMED2020.2020.11495OCS1509151

    Optimization of Pyrazole Compounds as Antibiotic Adjuvants Active against Colistin- and Carbapenem-Resistant Acinetobacter baumannii

    Get PDF
    The diffusion of antibiotic-resistant, Gram-negative, opportunistic pathogens, an increasingly important global public health issue, causes a significant socioeconomic burden. Acinetobacter baumannii isolates, despite causing a lower number of infections than Enterobacterales, often show multidrug-resistant phenotypes. Carbapenem resistance is also rather common, prompting the WHO to include carbapenem-resistant A. baumannii as a "critical priority" for the discovery and development of new antibacterial agents. In a previous work, we identified several series of compounds showing either direct-acting or synergistic activity against relevant Gram-negative species, including A. baumannii. Among these, two pyrazole compounds, despite being devoid of any direct-acting activity, showed remarkable synergistic activity in the presence of a subinhibitory concentration of colistin on K. pneumoniae and A. baumannii and served as a starting point for the synthesis of new analogues. In this work, a new series of 47 pyrazole compounds was synthesized. Some compounds showed significant direct-acting antibacterial activity on Gram-positive organisms. Furthermore, an evaluation of their activity as potential antibiotic adjuvants allowed for the identification of two highly active compounds on MDR Acinetobacter baumannii, including colistin-resistant isolates. This work confirms the interest in pyrazole amides as a starting point for the optimization of synergistic antibacterial compounds active on antibiotic-resistant, Gram-negative pathogens
    • …
    corecore