1,721,054 research outputs found
Performance and Emissions of a Natural Gas Fueled Two-Stroke SI Engine
No full textABSTRACT This paper presents the results of an experimental activity carried out on a two-stroke SI engine for moped (with a displacement 50 cm3) fueled alternatively by gasoline and natural gas. The effect of the fuel on engine performance and efficiency was evaluated comparing both instantaneous (pressure signal in the crankcase, cylinder and exhaust pipe) and overall data (torque, power, fuel consumption, emissions). Cylinder pressure was measured in order to evaluate the effect of fuel on the optimum ignition timing angle and on cyclic dispersion. Engine emissions were measured by means of a gas analyzer and a gas-chromatograph. Moreover this experimental analysis has been carried out also to validate the 1D-3D numerical model for the simulation of the scavenging and combustion processes in a small-size spark-ignition two-stroke engine. This activity is reported in another paper
Modelli di dispersione di specie in ambiente multi-patch
No full textposter presentato a GEONAPOLI Geologia e tutela del territorio- Convegno Annuale dei Dipartimenti di “Scienze della Terra” e “Geofisica e Vulcanologia”. 25 Giugno 200
Modelli di dispersione di specie in ambiente multi-patch
No full textposter presentato a GEONAPOLI Geologia e tutela del territorio- Convegno Annuale dei Dipartimenti di “Scienze della Terra” e “Geofisica e Vulcanologia”. 25 Giugno 200
Equivalence of information from single versus multiple frequency bioimpedance vector analysis in hemodialysis
No full textKidney Int. 2005 Jan;67(1):301-13.
Equivalence of information from single versus multiple frequency bioimpedance vector analysis in hemodialysis.
Piccoli A, Pastori G, Guizzo M, Rebeschini M, Naso A, Cascone C.
Source
Department Scienze Mediche e Chirurgiche, University of Padova, Padova, Italy. [email protected]
Abstract
BACKGROUND:
In suspended cells, low-frequency current only passes through extracellular fluids, while current at higher frequencies passes through extra- and intracellular fluids. Cells in soft tissues are in contact with each other, which causes tissue anisotropy, meaning that impedance changes along different cell directions, with part of low-frequency current also passing through cells. Hence, equivalent information on body impedance change is expected at all frequencies, which we proved in a dynamic condition of fluid removal with hemodialysis.
METHODS:
We performed whole-body impedance spectroscopy (496 frequencies from 4 to 1024 kHz, SEAC SFB3 analyzer; Brisbane, Australia) before and during fluid removal (0, 60, 120, 180 min, 2.5 kg) in 67 hemodialysis patients. With increasing current frequency, resistance (R) decreases and reactance (Xc) moves along the Cole's semicircle on the R-Xc plane.
RESULTS:
The Cole's semicircles progressively enlarged and moved to the right on the R-Xc plane following fluid removal (increase in both R and Xc values at any given frequency). Xc values at 5 kHz (expected values close to 0 Ohm) were 70% of the maximun Xc, indicating an intracellular current flows at low frequencies. The correlation coefficient between R at 50 kHz (standard frequency) and R at other frequencies ranged from 0.96 to 0.99, and the correlation coefficient between Xc at 50 kHz and Xc at other frequencies at any time point ranged from 0.65 to 0.99.
CONCLUSION:
From high Xc values at low frequency, tissue anisotropy is inferred. Intra- and extracellular current flow causes equivalence of information based on functions of R and Xc measurements made at 50 kHz versus other frequencies
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
Modelli di Relazione con l’Habitat (HRM) per Capriolo e Cinghiale nell’Appennino Abruzzese
No full textComo 8-10 Settembre 200
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