1,721,288 research outputs found

    Numerical Investigations on the Working Cycle of a Hydraulic Breaker: Off-Design Performance and Influence of Design Parameters

    No full text
    This paper deals with theoretical considerations and numerical simulations concerning the working behaviour of a hydraulic breaker. At first, some formulations coming from sufficiently reasonable considerations on the working principle of the breaker, based on the hypothesis of the motion of the striking mass as uniformly accelerated, are proposed. Later, a previously realized parameterised model is used in order to investigate the influence of the inlet flow rate and of the most important design parameters on the behaviour of the machine. This analysis allows the characterization of these parameters affecting breaker performance, suggesting possible design improvements which may lead to better performance in terms of both impact energy and efficiency

    LARVA Anisakis IN Sepia officinalis DEL MEDITERRANEO

    No full text
    The Authors report, for the first time, thepresence of an Anisakis larva in one specimenof Sepia officinalis, describing thecharacteristics of parasitic localization coexisting,moreover, with an Aggregata sp. infection. The AA conclude with some sanitaryand inspective considerations[...

    The Effects of Distributor and Striking Mass on the Performance of a Hydraulic Impact Machine

    No full text
    This paper deals with numerical investigations concerning the working behavior of a hydraulic impact machine. Attention is focused on the moving elements inside the casing of the breaker, taking the main targets to be achieved by the designer into account. On one hand, there is the operating performance optimization, with particular care devoted to the impact energy of the breaker; on the other hand, the energy conversion efficiency, related to the power transmission, in order to minimize the power requirement to the feeding system. Use of a parameterized numerical model is made in order to better understand the effects of parameters characteristic of distributor and striking mass on breaker performance and to achieve possible improvements in both impact energy and efficiency. The key-variable, which leads to better performance, is found to be the working pressure

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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
    corecore