367 research outputs found
Towards practical guidelines for conversion from fixed to reconfigurable manufacturing automation systems
It is generally considered that economic feasibility of a reconfigurable manufacturing system is only attainable if the system is defined to be reconfigurable at the outset of its design. In this work we consider the potential exception to this perception, in the context of a common industrial scenario where a specialized and expensive manufacturing machine or system will otherwise be rendered useless due to loss of business of the particular product being manufactured. Specific guidelines to convert from a fixed to a reconfigurable system are proposed, and evaluated through a case study. It is shown that under certain conditions, reconfigurable manufacturing systems may be economically feasible even if they are developed through the modification of pre-existing dedicated systems.peer-reviewe
KINEMATIC AND DYNAMIC ANALYSIS OF SPRINT START
Aims of this study were the tuning of the methods for kinematic and dynamic analysis of sprint start and the assessment of their relevance for field practice. Data collection was performed by means of an Elite Motion Analysis System (two cameras,3D) at 100 Hzi and a Kistler force platform (type 9281b ) at 500 Hz. Three elite athletes participated in the study; each subject performed three trials. statistical analysis ( ONEWAY ANOVA - SPSSPC software package) was performed in order to highlight significant differences ( F>0.05 ) between the subjects. The start movement was divided into three temporal phases: release of the starting block, landing on first supported push off from platform. significant differences were observed with respect to hip horizontal linear velocity within these phases (F > 0.02-0.001-0.0003) between the subjects. In order to give a complete description of the movement pattern four groups of variables were selected: 1)LINEAR DISPLACEMENTS. Eighteen variables were studied ; thirteen of them show significant differences index of different positions on the starting blocks -and different movement pattern during push-of f . 2)ANGULAR DISPLACEMENTS. Thirty-five variables were selected; eighteen show significant differences. 3) LINEAR AND ANGULAR-VEMCITIES Of the 54 variables studied (20 linear var. and 34 angular var.) , 38 (13 linear var. and 15 angular var. ) shows significant differences. 4)DYNAMIC DATA. We studied 62 variables, 26 of which showed significant differences. Exit velocity from starting blocks is influenced by the force produced during the first support phase and by the kinematics of the body segments. The different results obtained by the athletes in hip horizontal velocity, can be explained with the significant differences observed with respect to kinematic and dynamic of the phases of start studied. Main variables that shows significant differences are: hip, knee and ankle peak angular velocities, duration of first support phase and joint moments during push-off from first support phase. These variables seems to be logically related with the index of performance,hip horizontal velocity
Effect of Wastewater on the Composition of Bacterial Microbiota of Phragmites australis Used in Constructed Wetlands for Phytodepuration
Phytodepuration occurs in the plant-mediated remediation processes exploited to remove pollutants from wastewater, and Phragmites australis is one of the most used plants. This goal is achieved using constructed wetlands (CW), which are engineered systems designed to mimic the natural processes of pollutants removal. The aim of this work was to characterize the bacterial communities associated to P. australis, soils, and permeates of the CW of Calice (Prato, Italy), to evaluate the possible effect of wastewaters on the CW bacterial communities, through a next-generation sequencing-based approach. A total of 122 samples were collected from different tissues of P. australis (i.e., roots, aerial parts, and stem), soil (i.e., rhizospheric and bulk soil), and permeates, and analyzed. All samples were collected during five sampling campaigns, with the first one performed before the activation of the plant. Obtained results highlighted a specific microbiota of P. australis, conserved among the different plant tissues and during time, showing a lower alpha diversity than the other samples and not influenced by the more complex and variable environmental (soils and permeates) bacterial communities. These data suggest that P. australis is able to select and maintain a defined microbiota, a capacity that could allow the plant to survive in hostile environments, such as that of CW
Mediterranean Sea large-scale low-frequency ocean variability and water mass formation rates from 1987 to 2007: A retrospective analysis
We describe a synthesis of the Mediterranean Sea circulation structure and dynamics from a 23-year- long reanalysis of the ocean circulation carried out by Adani et al. (2011). This mesoscale permitting dynamical reconstruction of past ocean variability in the Mediterranean Sea allows the study of the time-mean circulation and its low frequency, decadal, components. It is found that the time-mean circu- lation is composed of boundary and open ocean intensified jets at the border of cyclonic and anticyclonic gyres. The large scale basin circulation is generally characterized in the northern regions by cyclonic gyres and in its southern parts by anticyclonic gyres and eddy-dominated flow fields, with the exception of the Tyrrhenian and the northern Ionian Sea. The time-mean Tyrrhenian Sea circulation is dominated by cyclonic gyres of different intensity and intermittency. The northern Ionian Sea circulation, however, reverses in sign in two ten-year periods, the first in 1987–1996 and the second in 1997–2006, which is here called the Northern Ionian reversal phenomenon. This reversal is provoked by the excursion of the Atlantic-Ionian Stream from the middle to the northern parts of the basin. The decadal variability of other parts of the basin is characterized by changes in strength of the basin scale structures. The water mass formation rates and variability are dominated by event-like periods where the intermediate and deep waters are formed for 2–3 years at higher rates. The largest deep water formation events of the past 23 years occurred separately in the western and eastern Mediterranean basin: the first coincided with the Eastern Mediterranean Transient (Roether et al., 1996) and the second with the western Mediterranean deep water formation event in 2005–2006 (Smith et al., 2008). A new schematic of the basin-scale circu- lation is formulated and commented.Published318-3324A. Oceanografia e climaJCR Journa
Temporal Evolution of Bacterial Endophytes Associated to the Roots of Phragmites australis Exploited in Phytodepuration of Wastewater
Improvement of industrial productions through more environment-friendly processes is a hot topic. In particular, land and marine environment pollution is a main concern, considering that recalcitrant compounds can be spread and persist for a long time. In this context, an efficient and cost-effective treatment of wastewater derived from industrial applications is crucial. Phytodepuration has been considered as a possible solution and it is based on the use of plants and their associated microorganisms to remove and/or transform pollutants. In this work we investigated the culturable microbiota of Phragmites australis roots, sampled from the constructed wetlands (CWs) pilot plant in the G.I.D.A. SpA wastewater treatment plant (WWTP) of Calice (Prato, Tuscany, Italy) before and after the CW activation in order to check how the influx of wastewater might affect the resident bacterial community. P. australis specimens were sampled and a panel of 294 culturable bacteria were isolated and characterized. This allowed to identify the dynamics of the microbiota composition triggered by the presence of wastewater. 27 out of 37 bacterial genera detected were exclusively associated to wastewater, and Pseudomonas was constantly the most represented genus. Moreover, isolates were assayed for their resistance against eight different antibiotics and synthetic wastewater (SWW). Data obtained revealed the presence of resistant phenotypes, including multi-drug resistant bacteria, and a general trend regarding the temporal evolution of resistance patterns: indeed, a direct correlation linking the appearance of antibiotic- and SWW-resistance with the time of exposure to wastewater was observed. In particular, nine isolates showed an interesting behavior since their growth was positively affected by the highest concentrations of SWW. Noteworthy, this study is among the few investigating the P. australis microbiota prior to the plant activation
Compared clinical efficacy and bone metabolic effects of low-dose deflazacort and methyl prednisolone in male inflammatory arthropathies: a 12-month open randomized pilot study.
Objective. To evaluate: (i) a correct equivalence ratio of clinical efficacy between low-dose deflazacort (DFZ) and methyl prednisolone (MP); and (ii) bone metabolic effects of low-dose DFZ and MP in the treatment of male RA and PsA.
Methods. A total of 21 male patients with active RA or PsA, naive to steroid treatment were chosen for the study. Group I: 10 patients treated for 6 months with DFZ 7.5 mg, calcium, cholecalciferol and a DMARD; for the following 6 months with MP 4 mg, calcium, cholecalciferol and a DMARD. Group II: 11 patients treated for 6 months with MP 4 mg, calcium, cholecalciferol and a DMARD; for the following 6 months with DFZ 7.5 mg, calcium, cholecalciferol and a DMARD. At day 0, 90, 180, 240 and 360 evaluation of ACR improvement criteria; a blood sample for total and bone-specific ALP, calcium, phosphorus, PTH, SHBG, estradiol, ACTH, osteocalcin, LH, OPG; a sample of urine for calcium, phosphorus, creatinine and DPD.
Results. 13/21 patients (6/10 Group I; 7/11 Group II) reached ACR 20 at 6 months; 14/21 (7/10 Group I, 7/10 Group II) at 12 months. Only at the third month we observed in Group II vs Group I a reduction of OPG (24% vs 6%, P= n.s.); ALP (P < 0.001) and osteocalcin (P = 0.006) decreased in both groups from the third month; DPD decreased in both groups only from the sixth month (P = 0.002).
Conclusions. The correct equivalence ratio of DFZ to MP is 1.875:1, and of DFZ to prednisolone 1.5:1. We found a relative prevalence of bone resorption compared to bone formation in the first 6 months of treatment. The trend of OPG requires further investigation
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