Seismic Response of a Platform-Frame System with Steel Columns

Timber platform-frame shear walls are characterized by high ductility and diffuse energy dissipation but limited in-plane shear resistance. A novel lightweight constructive system composed of steel columns braced with oriented strand board (OSB) panels was conceived and tested. Preliminary laboratory tests were performed to study the OSB-to-column connections with self-drilling screws. Then, the seismic response of a shear wall was determined performing a quasi-static cyclic-loading test of a full-scale specimen. Results presented in this work in terms of force-displacement capacity show that this system confers to shear walls high in-plane strength and stiffness with good ductility and dissipative capacity. Therefore, the incorporation of steel columns within OSB bracing panels results in a strong and stiff platform-frame system with high potential for low- and medium-rise buildings in seismic-prone areas

Esecuzione e interpretazione di prove sperimentali su pareti realizzate con tecnologia "ISOSPAN".

In recent years, the resistance of reinforced concrete bearing panels structures has been the object of several research works, to assess the effective behavior of this kind of materials in static and seismic situations. Despite the wide use of this kind of concrete walls in Northern Europe the national regulations are not very detailed and specific. In fact, regarding the structural elements without reinforcement or partially reinforced employed in the industrial buildings, there are no common methods or approved procedures to calculate the strength of this kind walls, both Italian and European (Eurocodes) regulations. In order to partially fill this gap the Italian Ministry of Public Works issued some Guidelines in the July 2011 concerning the construction technique in object, where a series of laboratory tests should be carried on to investigate the mechanical properties (Young and shear moduli) and the panels behavior under different loads and with different geometries. This paper presents a summary of the experimental results of some tests conducted following the above Guidelines and the comparison of these with the analytical results of a proposed procedure

LA ACREDITACIÓN DE CARRERAS DE POSGRADO: EXPERIENCIAS EN LA FACULTAD DECIENCIAS EXACTAS, INGENIERIA Y AGRIMENSURA DE LA UNIVERSIDAD NACIONAL DE ROSARIO

La Escuela de Posgrado y Educación Continua de la Facultad de Ciencias Exactas, Ingeniería y Agrimensura de la Universidad Nacional de Rosario cuenta desde el año 2001 con un Área de Acreditación de carreras de posgrado. En esos años se ofrecían ocho carreras de posgrado ampliándose la oferta educativa, en la actualidad, a dieciséis. Todas estas carreras han sido evaluadas y acreditadas ante la Comisión Nacional de Evaluación y Acreditación Universitaria con resultado positivo. En este tiempo hemos trabajado adaptándonos a los cambios en los procesos y protocolos establecidos desde la Nación y desde nuestra Universidad, implementando estrategias de gestión propia, inherentes a la Facultad, para la búsqueda, obtención y procesamiento de la información necesaria para cada etapa de acreditación. El proceso de acreditación se convirtió en una forma de trabajo continua y sostenida a lo largo del tiempo ayudando a tomar decisiones estratégicas para la institución. Presentamos nuestra experiencia después de casi una década de trabajo continuo

Controllo passivo della risposta sismica di edifici prefabbricati con l'uso di connessioni dissipative

At the end of May 2012, a seismic sequence struck the Emilia region in northern Italy, with two main events of local magnitude ML 5.9 and 5.8. Emilia has been classified as a seismic area only recently. Consequently almost all of the precast buildings that have been erected in the past decade haven't been designed with provisions for seismic resilience. Surveys after the earthquake allowed the identification of the damage types and their location: column base, column top, on shed beam, on roof element, on cladding/ infill panels. The scenario confirmed structural damages surveyed after the earthquake in L'Aquila (Menegotto, 2009), (Colombo, 2012). Particularly, it has been pointed out that the weakest elements in precast buidings are connections. Indeed, in precast structures, unlike traditional RC buildings, the design and construction of efficient connections is still a open issue. The connections of cast-in-situ structures present a higher degree of continuity between adjacent elements, also due to passing reinforcing bars. In case of seismic events, joints represent a source of energy dissipation and allow for a redistribution of internal forces (if properly designed). These characteristics lack in many precast buildings, especially in those with industrial applications, which are usually characterized by beams/roof elements simply supported by columns. In such structures, seismic improvement can’t be performed through the introduction of rigid connections, which would increase the stiffness of the structure (which is initially flexible) and lead to unpredictable and sometime negative results such as an increase of the base shear. Moreover, it is not simple to design connections strong enough to resist to stresses induced by earthquakes. Passive control techniques use devices that don’t need energy to work, thus they are very reliable because they won’t malfunction if a black-out occurs. They seem a promising solution for seismic improvement of precast existing buildings. A possible intervention is the introduction of dissipative connections, which would lead to an increase of the behavior factor through energy dissipation. Dissipative connections can be located between different structural/non-structural elements: between roof elements and edge beams, between pillars and edge beams, or between infill panels. This work is focused on the introduction of dissipative connections between roof elements and the substructure. In particular, the objective is finding an algorithm to define the yielding force of connections in function of the maximum relative displacement allowed between roof elements and substructure. The complex phenomenon, which involves plasticity and the dynamic response of the system, is described through simple equations in order to have a powerful but simple instrument for design. The proposed algorithm allows to define the yielding force of roof connections in function of the elastic and inertial features of the examined system, with no need of non-linear dynamic analysis which are difficult to perform and usually lead to ambiguous results

Biodiversités « utile » et « nuisible » dans les agrosystèmes : importance pour la lutte biologique par conservation

La lutte biologique par conservation repose sur la mise en place d’aménagements dans ou autour de parcelles cultivées ou de modifications des pratiques culturales de façon à favoriser la régulation des ravageurs des cultures par des auxiliaires de lutte biologiques indigènes. Pour être efficaces, les méthodes de lutte biologique par conservation nécessitent toutefois plusieurs pré-requis : (i) une bonne compréhension de la biodiversité associée aux agrosystèmes, (ii) l’optimisation des échanges entre la culture et les autres composantes de l’agrosystème, (iii) la prise en compte d’éventuels effets non-intentionnels associés aux auxiliaires favorisés. Ces trois points sont discutés dans le cadre d’un programme en cours dont l’objectif est d’évaluer l’intérét d’une plante méditerranéenne, l’inule visqueuse Dittrichia viscosa L. (W. Greuther) (Asteraceae), pour la régulation de ravageurs dans deux agrosystèmes, l’oliveraie et la culture sous serres

Strength training protocols in hemiparetic individuals post stroke: a systematic review

Introduction: Hemiparesis is one of the main sequels of stroke. Evidence suggests that muscle strength exercises are important in rehabilitation programs for hemiparetic patients, but wide variation in previously studied protocols makes the most suitable choice difficult in clinical practice. Objective: The aim of this study was to investigate strength training protocols for people with hemiparesis after stroke. Methods: A systematic review of literature was performed in the PubMed, PEDro (Physiotherapy Evidence Database), SciELO (Scientific Electronic Library Online), and LILACS (Latin American and Caribbean Literature in Health Science) databases. Only controlled clinical studies that contained strength training protocols for hemiparesis after stroke were selected. Results: In total, 562 articles were found. Of them, 12 were accepted for the systematic review. Although strength training protocols are effective in hemiparetic patients, we did not found a standard method for strength training. Conclusion: This systematic revision highlights the lack of a standard protocol for strength training, considering the following training parameters: volume, intensity, frequency, series, and repetitions. Isotonic exercises are most commonly used

“Keep it simple”: the introductions of Veterinary Medicine academic papers

This study investigates the linguistic organization of the introduction sections of academic papers from the Veterinary Medicine field in terms of the two basic systems that determine how one clause is related to another: taxis (degree of interdependency) and logico-semantic relation (Halliday; Matthiessen, 2014, p. 438). All the clauses from the introduction sections of five published academic papers were analyzed. The results showed a high recurrence of simple clauses and embedded clauses in the corpus. In the clause complexes, the preference is for paratactic extensions. The results of this analysis may help understanding the functioning of academic writing in English language in this specific field.This study investigates the linguistic organization of the introduction sections of academic papers from the Veterinary Medicine field in terms of the two basic systems that determine how one clause is related to another: taxis (degree of interdependency) and logico-semantic relation (Halliday; Matthiessen, 2014, p. 438). All the clauses from the introduction sections of five published academic papers were analyzed. The results showed a high recurrence of simple clauses and embedded clauses in the corpus. In the clause complexes, the preference is for paratactic extensions. The results of this analysis may help understanding the functioning of academic writing in English language in this specific field.  Keywords: clause complex; Veterinary Medicine; academic writing.