520 research outputs found
LONG TIME BEHAVIOR OF A SHALLOW WATER MODEL FOR A BASIN WITH VARYING BOTTOM TOPOGRAPHY
No full textWe study the long time behavior of a shallow water model introduced by Levermore and Sammartino to describe the motion of a viscous incompressible fluid confined in a basin with topography. Here we prove the existence of a global attractor and give an estimate on its Hausdorff and fractal dimension
Second campaign of microclimate monitoring in the carcer tullianum: temporal and spatial correlation and gradients evidenced by multivariate analysis
No full textAbstract Background This paper discusses results obtained in the second monitoring campaign of the Carcer Tullianum, a particular hypogeum environment located in the historical centre of Rome (Italy). In the first paper we stressed the need to apply chemometric tools to this kind of studies in order to obtain full and significant information; really information on sampling design, sensors (type, number, position) and instrument validation seems to be not easy to find in literature for researches dealing with monitoring of indoor environments. Also in this case three main parameters (temperature, humidity, illuminance) were monitored in the complex construction by an inexpensive self-assembled system along some horizontal and vertical vectors together with some measurements of oxygen, carbon dioxide and barometric pressure. With respect to the first campaign, we used a higher number of sensors to cover a new excavated zone; for the same reason, as well as to take into account the presence of visitors, a different experimental design was adopted. Results Different data treatments were applied to data coming from all the used sensors. A good view of the microclimate was obtained that also resulted coherent with the different position of the three rooms constituting the monitored site (Carcer, Tullianum, Convent). Classical time plots resulted useful to evidence the correlation of the main monitored parameters (T, RH% and illuminance) with macroclimate, as well as their delay in following macroclimate. Box-Whisker and Gain-Loss graphs evidenced at the best the microclimate differences between the three rooms; an almost hypogean microclimate was evidenced for the lower room (Tullianum) where humidity values range between 90 and 100% while lower values, but anyway higher than the external, and spread more widely were measured passing to Convent and Carcer with minimum values around 50% for the last. A scarce or very scarce correlation with macroclimate was evidenced for all the three main measured parameters. Lighting results mainly dependent on artificial light and only in few cases, but unfortunately in the most precious zone, illuminance exceeds values suggested by Normative. Conclusions Box-Whisker and Gain-Loss graphs allowed us to have the best view of the microclimate for all the monitored rooms. The influence of lighting by lamps on the other monitored parameters resulted overlapped and clearly topped the solar one. The worst situation was found in the Carcer, where the presence of the main chandelier worsens the state of the frescoed walls, already subjected to wide changes in temperature and humidity. Also the lighthouse located above the Convent provokes lighting exceeding values suggested by Normative while, as expected, LEDs resulted as suitable source of light from a conservation point of view. Susanne Heidi Plattner, Patrizia Fortini and Maria Pia Sammartino contributed equally to this work</p
Well-posedness of the boundary layer equations
No full textWe consider the mild solutions of the Prandtl equations on the half space. Requiring analyticity only with respect to the tangential variable, we prove the short time existence and the uniqueness of the solution in the proper function space. The proof is achieved applying the abstract Cauchy-Kowalewski theorem to the boundary layer equations once the convection-diffusion operator is explicitly inverted. This improves the result of [M. Sammartino and R. E. Caflisch, Comm. Math. Phys., 192 (1998), pp. 433-461], as we do not require analyticity of the data with respect to the normal variable
Do CEE’s Directives Really Compliance with the Kyoto Protocol? A Case Study: Fuel Consumption of one Toyota’s “Little Genius”
No full textDeveloped Countries that signed the Kyoto Protocol are required to attain the established
limits to the greenhouse gas (GHG) emissions or to pay penalty for the exceeding amount. In order
to comply with the Protocol, CEE strategy is based on capillary information of fuel consumption of
motor vehicles, to be done by producers, coupled to economic incentives to users in order to
encourage ecological choices. The need to standardize the measure of GHG emission, related to the
fuel consumption of a vehicle, allowed the drawing up of a very detailed procedure that includes the
choice of driving simulation on urban and extra-urban cycles.
Many drivers claim that the difference between consumption of their own car and values
declared by the producer is too high; tests performed by experts and published on trade journals
such as Quattroruote (Italy) and Autobild (Germany), also demonstrate this datum; unfortunately
nothing can be done to go against producers as such differences mainly depend on almost
unrealistic car use simulations. Car producers fully respect the 98/69/CE [1] while the 1999/94/CE
[2] is not so carefully followed. Moreover, the presented case study evidences that the board
computer (BC), also currently equipping also
small cars, furnishes false data aiming to
convince driver of fuel consumption that is
lower than the real one. Does this also
happens on other cars? Is it correct that a
consumer must pay an instrument to obtain
misleading advertising
Existence and uniqueness for Prandtl equations and zero viscosity limit of the Navier-Stokes equations
No full textThe existence and uniqueness of the mild solution of the boundary layer
(BL) equation is proved assuming analyticity of the data with respect to
the tangential variable. Moreover we use the well-posedness of the BL
equation to perform an asymptotic expansion of the Navier-Stokes
equations on a bounded domain
Impianto di illuminazione a LEDs e relativo procedimento per inibire lo sviluppo di organismi biodeteriogeni fotosintetici in ambienti ipogei
No full textE\ stato messo a punto un sistema di illuminazione composto da serie di Led monocromatici di lunghezze d'onda che escludono quelle in grado di attivare la fotosintesi e quindi la crescita di biodeteriogeni che la utilizzano. E' studiato per l'illuminazione di ambienti ipogei di interesse storico artistico, pertanto e' possibile modulare l'intensita' dei singoli Led o gruppi di Led per ottenere una luce in grado di far apprezzare al megloi il colore della zona da illuminare.Puo' comunque essere utilizzato in qualunque ambiente ipogeo anche ad uso civile. I Led sono facilmente sostituibili per ottenere spettri diversi in grado di inibire la crescita di diversi biodeteriogeniThe invention relates to the field of illumination and in particular concerns a LED lighting system,
to be used for illuminating hypogeal environments, which is able to trigger no photosynthetic reactions
and, consequently, to hinder the development of photosynthetic biodeteriogen organisms, as well as a
process for inhibiting the growth of said organisms
Preliminary Study to Set up a Non Destructive In Situ Method to Monitor Soluble Salts Content in Stone Materials; The Usefulness of a Multivariate Approach
No full textNew equipments and procedures to monitor in situ soluble salts content in stone materials were set up. They base on the extraction, by flowing ultrapure water, of soluble salts from stone surfaces and on the continuous registration of the real-time response of a conductometric probe; on the final collected solution, conductivity measure and analysis of anions by ionic chromatography can be performed in laboratory. A correlation between the signal obtained in situ and the chromatographic data was looked for; satisfying results were obtained but further investigation are needed in order to take into account all the involved parameters/variables and to extract the most significant index from the signal curve. It must be stressed that the actual normative on Cultural Heritage is scarce and in some case doesn't ensure a fully correct analytical procedure; anyway we compared our method with that indicated in the UNI11087. Surely a multivariate approach will be of help to optimize both the equipment and the procedure. The engineering of the apparatus must be improved too, so the presented results must be considered preliminary
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