1,721,108 research outputs found
A review of design and assessment methods for skew concrete slabs
No full textConcrete slabs are often used for short-span bridges where it is required to limit the deck construction depth. Alongside, skew decks are helpful when there are space con-straints in the bridge construction area, e.g., in urban areas, thus they are not uncommon. Nonetheless, skew slabs are not as much investigated as straight slabs and comprehensive guidance on their design or assessment is generally lacking. This is particularly the case for the shear behaviour of skew concrete slabs, which exhibit significant load concentrations around the obtuse corners with observed failure modes that are intermediate between the traditional cases of one-way and two-way (punching) shear. A reliable estimation of the shear strength is beneficial for both design and assessment: in fact, if shear strength is over-estimated, it may lead to undesired brittle failures, whereas if it is under-estimated, it may lead to inefficient design or unnecessary interventions to existing structures. This paper reviews the provisions of three codes of practice on shear design (Eurocode 2, the Swiss SIA 262, and fib Model Code 2010), as well as main research on skew slabs. Procedures for extending the code provisions to skew slabs are presented and then applied to a case study. Some scatter is found across different codes of practice, broadly reflecting their complexity. The findings may be useful to practitioners with the design and assessment of skew concrete slabs
A comparison of Italian and UK guidelines on the vulnerability assessment of bridges
No full textThe vulnerability assessment of bridges has proven to be a challenging task: as of yet, there is no universal approach for carrying out the assessment; besides, in spite of recent technological advances, it still greatly relies on visual inspections, hence with a certain degree of subjectivity, and the assessment outcome may be affected by some factors that are not obvious, such as full accessibility of the bridge and presence of latent defects. This paper compares the structural vulnerability assessment of existing highway bridges included in two national guidance documents, namely the well-established UK Design Manual for Roads and Bridges and the recent Italian Ministry of Infrastructure and Transport’s Guidelines. Both documents present risk-based methods for assessing the structural vulnerability of bridges, while exhibiting fundamentally different approaches. For instance, the Italian assessment defines a vulnerability class, to be combined with hazard and exposure classes in order to determine a structural risk rating; then, the overall rating affects the actions that need to be taken, e.g. subsequent inspections, structural assessment or monitoring. On the other hand, the UK guidance uses a risk scoring system, which also includes some parameters not strictly related to vulnerability, in order to determine whether the interval between principal inspections may be increased from the minimum requirement of 6 years; some input data for such risk scoring are also used to determine whether a structural assessment is required. Finally, both vulnerability assessments are applied to two sample bridges, highlighting similarities and differences between the two guidelines. The presented comparison may allow for a better understanding of the factors governing the assessment outcome, for potential improvement of guidelines, and ultimately for more effective intervention prioritisation
Quantitative study of ANP in hypothalamic supraoptic and paraventricular nuclei in trained rats.
No full textOntogeny of peptides vasopressin,oxytocin ANP (Atrial Natriuretic Peptide) in some hypothalamic nuclei in rat embryos)
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
ANP PRESENCE IN THE HYPOTHALAMIC SUPRACHIASMATICUS NUCLEUS OF DEVELOPING RAT
No full textIn previous research, we studied both the oxytocin and vasopressin ontogeny in the hypothalamic supraoptic and paraventricular nuclei, and the ANP-ontogeny in the hypothalamic supraoptic nucleus. In this paper we evaluate the ANP-ontogeny in the rat hypothalamic suprachiasmatic nucleus; infact the suprachiasmatic nucleus it is known to synthesize vasopressin, a peptidic hormone involved in the homeostasis of the body fluids by an antagonistic role to ANP. Immunohistochemical techniques show that ANP is present in the hypothalamic suprachiasmatic nucleus of the rat at 18 degrees day of i.u. life and at 0 degrees to 3 degrees day of postnatal life. PCR analysis confirms the ANP-mRNA expression. Thus, it is possible to adfirm that the suprachiasmatic nucleus is a synthesis site of ANP, and ANP appears in both the supraoptic and suprachiasmatic nuclei at the same developmental stage. Moreover, ANP and vasopressin appear at the same developmental stage since both the peptides are involved in the homeostasis of body fluids
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