117,988 research outputs found
FE simulation and experimental analysis on bearing capacity of the runway strips
No full textThe aim of this study was to establish reasonable values for both maximum deflection and minimum bearing capacity of runway strips, conforming to regulations specified by the Italian Civil Aviation Authority (ENAC), to implement in the design and reabilitation of the runway strips of the Cagliari Airport in Italy. The ENAC regulations state that the bearing capacity of runway strips must be designed based on the characteristics of both the critical aircraft and emergency vehicles which may transit on the runway. However, it does not specify a minimum bearing capacity value. Therefore, based on the instructions given by ENAC regulations, required values for both maximum deflection and minimum bearing capacity were determined using a Finite Element Method (FEM) simulation to design runway strips. In particular, a non‐linear analysis was conducted with FEM to simulate the mechanical behavior of granular soil under high instantaneous pressures. The paper explains how the theoretical analysis was conducted, which materials were tested, and how runway strips were designed. Before the construction, extensive on‐site testing was performed to validate the results obtained with the theoretical analysis. In particular, 122 series of single and double cycle bearing capacity plate and Light Weight Dropping (LWD) tests were performed. Results from these tests were used to define critical areas and to estimate any degree of correlation between the bearing capacity plate and LWD tests. The theoretical and experimental analyses carried out on this case study have enabled a design criterion and facilitated the rebuilding of the emergency strips of the Cagliari Airport in Italy, conforming to regulations specified by the ENAC. The results obtained with the theoretical analyses were validated by performing extensive on‐site testing
Brain dialysis and dopamine: does the extracellular concentration of dopamine reflect synaptic release?
No full textWe considered the drug-induced circling behaviour of rats monolaterally lesioned with kainic acid (KA) as a marker of the dopamine (DA) concentration in the synaptic space. D-Amphetamine produced a dose-related increase in the DA concentration of the dialysate from an intact striatum and a proportional number of ipsilateral circlings. Pargyline or L-dihydroxyphenylalanine (L-Dopa), alone or in combination with benserazide, increased the concentration of DA to a similar or even higher level than d-amphetamine, but failed to elicit a circling response. Apomorphine given after these drugs at the peak of DA accumulation always induced circling behaviour. The results suggest that released DA may undergo different inactivation processes before reaching the dialysis probe, and that these processes may be differentlly affected by drug treatments. Alternatively, it may be suggested that DA can be released into the synaptic space, in a functional manner, or into the interstitial fluid, from where it cannot reach the synaptic receptors. © 1990
Brain dialysis provides evidence for D2-dopamine receptors modulating noradrenaline release in the rat frontal cortex
No full textUma Igreja de portas abertas: nos caminhos do Papa Francisco
No full textResenha do Livro de SANCHES, W. L.; FIGUEIRA. E. Uma Igreja de portas abertas: nos caminhos do Papa Francisco. Publicado pela editora Paulinas em 2016
Runway instrumentation and response measurements
No full textThis paper presents ongoing research to measure the in situ response to airplane traffic of flexible pavement on a runway at Cagliari-Elmas Airport in Italy. Understanding how pavement materials respond to traffic and environmental loading is fundamental to designing pavements and assessing their performance. The pavement material behavior is affected by many factors (i.e., load magnitude, material properties, and environmental conditions). The influence of these factors can be simultaneously taken into account by measuring in situ stresses and strains using embedded instruments. The pavement layers of the Cagliari-Elmas runway were equipped with 149 instruments: 36 linear variable differential transformers, 36 pressure cells, four time domain reflectometers, 28 T-thermocouples, and 45 hot-mix asphalt strain gauges. The instrumented area, 55 m2, allows measuring the responses during three main loading maneuvers: taking off, landing, and taxiing. The preliminary data acquired during and after the runway's construction and before its opening to airplane traffic and its analysis show that the instrumentation process was a success. The instrument response testing includes falling weight deflectometer, truck, and airplane loading of various types, magnitudes, and speeds. The collected data were successfully compared with preliminary numerical simulations. Further data collection and research will be performed, particularly involving airplane traffic data. Data analysis will include the effect of the environmental data (i.e., moisture and temperature) and airplane configuration and speed. The collected data will be used to validate advanced pavement modeling and predict pavement runway performance. In addition, data resulting from this research have the potential to support and improve runway pavement design and to improve the evaluation process for new and existing runway pavement performance and damage prediction
Stress increases noradrenaline release in the rat frontal cortex: Prevention by diazepam
No full textFoot-shock produced a more than 2-fold increase in noradrenaline (NA) release from the frontal cortex of freely moving rats. The effect of acute stress was almost completely prevented by the administration of diazepam (5 mg/kg i.p.). Diazepam alone inhibited cortical NA release, the maximal inhibition (-57%) being observed 90 min after the injection. Cortical NA release therefore appears to be a reliable index of central noradrenergic activity in response to stressful conditions. © 1990
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
As portas de abertura de o evangelho segundo Jesus Cristo
No full textCet article cherche à analiser les épigraphes et le premier chapitre de L’ evangileselon Jesus Christ qui constituent les portes d’ouverture du roman.Este trabalho pretende analisar as epígrafes e o primeiro capítulo de O evangelhosegundo Jesus Cristo que se configuram como portas de abertura do romance
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