852 research outputs found
2-D constrained Navier-Stokes equation and intermediate asymptotics
We introduce a modified version of the two-dimensional Navier-Stokes
equation, preserving energy and momentum of inertia, which is motivated by the
occurrence of different dissipation time scales and related to the gradient
flow structure of the 2-D Navier-Stokes equation. The hope is to understand
intermediate asymptotics. The analysis we present here is purely formal. A
rigorous study of this equation will be done in a forthcoming paper
Life Cycle Assessment of a Lithium-Ion Battery Pack Unit Made of Cylindrical Cells
Saving energy is a fundamental topic considering the growing energy requirements with respect to energy availability. Many studies have been devoted to this question, and life cycle assessment (LCA) is increasingly acquiring importance in several fields as an effective way to evaluate the energy demand and the emissions associated with products’ life cycles. In this work, an LCA analysis of an existent lithium-ion battery pack (BP) unit is presented with the aim to increase awareness about its consumption and offering alternative production solutions that are less energy intensive. Exploiting the literature data about cradle-to-grave and cradle-to-gate investigations, and after establishing reasonable approximations, the main BP sub-elements were considered for this study, such as the plastic cells support, the Li-ion cells brick, the PCBs for a battery management system (BMS), the liquid-based battery thermal management system (BTMS) and the BP container. For each of these components, the impacts of the extraction, processing, assembly, and transportation of raw materials are estimated and the partial and total values of the energy demand (ED) and global warming potential (GWP) are determined. The final interpretation of the results allows one to understand the important role played by LCA evaluations and presents other possible ways of reducing the energy consumption and (Formula presented.) emissions
Appropriate lung management in patients with primary antibody deficiencies
Introduction: Human primary immunodeficiency diseases (PIDs) include a broad spectrum of more than 350 disorders, involving different branches of the immune system and classified as 'rare diseases.' Predominantly antibody deficiencies (PADs) represent more than half of the PIDs diagnosed in Europe and are often diagnosed in the adulthood. Areas covered: Although PAD could first present with autoimmune or neoplastic features, respiratory infections are frequent and respiratory disease represents a relevant cause of morbidity and mortality. Pulmonary complications may be classified as infection-related (acute and chronic), immune-mediated, and neoplastic. Expert opinion: At present, no consensus guidelines are available on how to monitor and manage lung complications in PAD patients. In this review, we will discuss the available diagnostic, prognostic and therapeutic instruments and we will suggest an appropriate and evidence-based approach to lung diseases in primary antibody deficiencies. We will also highlight the possible role of promising new tools and strategies in the management of pulmonary complications. However, future studies are needed to reduce of diagnostic delay of PAD and to better understand lung diseases mechanisms, with the final aim to ameliorate therapeutic options that will have a strong impact on Quality of Life and long-term prognosis of PAD patients
Cytotaxonomical considerations on Epipactis robatschiana (Orchidaceae), new species from Calabria (S Italy)
Abstract Epipactis robatschiana is a new species, described from Calabria (S Italy), where it grows in underwood of acidophilous pine-forests and beech-forests. This species is diploid with chromosome number 2n=2x=38. The karyotype is asymmetrical and consists of 4 large and 15 small chromosome pairs. C-banding patterns of this new species is quite similar to those of the other species of E. muelleri group, but it differs in the distribution of some heterochromatin bands. Its ecology and relationships with allied species are discussed too
Retrieval and analysis of land surface microwave emissivity from SSM/I data
The retrieval of land surface emissivity from microwave radiometric measurements is useful
for monitoring the surface properties without being affected by the contribution of the atmosphere,
which can be significant at higher frequencies. It is based on the inversion of the radiative
transfer equation, assuming the absence of scattering phenomena. In this work, a method
to improve the accuracy of the emissivity estimates through the removal of the effects of the
atmosphere from the radiometric data and through the consideration of the surface elevation
information is proposed. We have used the Special Sensor Microwave/Imager (SSM/I) observations
over Italy throughout 1995. The atmospheric parameters have been derived from
the NCEP vertical profiles, whilst the presence of clouds has been detected through METEOSAT
images co-located with the SSM/I ones. The data provided by a digital elevation model
(DEM) have been also exploited. Monthly average maps of microwave emissivity relative
to a geographical area including Italy have been produced to assess the whole estimation
procedure, as well as to give examples of monitoring the seasonal trend of this parameter in a
mountainous zone (Alps) and in a flat area (Po Plain)
PYDBSCAN UN SOFTWARE PER IL CLUSTERING DI DATI
Con il termine clustering si indica il processo mediante il quale è possibile raggruppare oggetti in base
a caratteristiche comuni (features). Questo approccio, alla base dei processi di estrazione di conoscenza da
insiemi di dati (data mining), riveste notevole importanza nelle tecniche di analisi. Come verrà mostrato in
questo lavoro, l’applicazione delle tecniche di clustering consente di analizzare dataset, con l’obiettivo di
ricercare strutture che possano fornire informazioni utili circa i dati oggetto dello studio. Gli ambiti in cui tali
algoritmi sono impiegati risultano essere eterogenei, a partire dalle analisi di dati biomedici, astrofisici,
biologici, fino ad arrivare a quelli geofisici. La letteratura è ricca di vari casi di studio, dai quali il ricercatore
può trarre spunto e adattare i differenti approcci alle proprie esigenze.
Il software PyDBSCAN, oggetto del presente lavoro, permette di applicare tecniche di clustering basate
sul concetto di densità , applicate ad oggetti (o punti) appartenenti ad insiemi definiti in uno spazio metrico.
L’algoritmo di base è il DBSCAN (Density Based Spatial Clustering on Application with Noise) [Ester et al.,
1996], di cui viene riportata una implementazione ottimizzata al fine di migliorare la qualità del
processamento dei dati. Schematicamente, il sistema proposto può essere rappresentato come in Fig. 1. Il
software, sviluppato in Python 2.6 [Python ref.], utilizza le librerie scientifiche Numpy [Numpy ref.],
Matplotlib [matplotlib ref.] e la libreria grafica PyQt [PyQt ref.] impiegata nella realizzazione dell’interfaccia
utente. Python è un linguaggio di programmazione che permette la realizzazione di applicazioni crossplatform
in grado di funzionare su diversi sistemi operativi quali Windows, Unix, Linux e Mac OS.
Nella prima parte del lavoro verranno brevemente descritte le tecniche oggetto del software presentato,
mentre nella seconda parte verrà descritto un esempio di applicazione su dati reali
Rhabdomyosarcoma of Soft Tissues in an Adult Brook Trout (Salvelinus fontinalis)
This report describes a spontaneously arising rhabdomyosarcoma of soft tissues in a brook trout (Salvelinus fontinalis). The lesion was examined by means of histology, immunohistochemistry (IHC) and transmission electron microscopy (TEM). The cross-reactivity of the primary antibodies used in the IHC was investigated in silico using the Protein Blast system. Microscopically, the lesion appeared as a 'small round cell' undifferentiated sarcoma with rare myotube formation. IHC identified expression of sarcomeric actin and vimentin and these molecules showed the highest protein sequence identity. Lower protein sequence identity coincided with negative immunolabelling for desmin, MyoD1, myogenin and CD3. TEM revealed myofibrils, but without a defined sarcomeric architecture. The diagnosis of solid alveolar rhabdomyosarcoma of soft tissues was achieved on the basis of histological and ultrastructural finding
Experimental Investigation on Latent Thermal Energy Storages (LTESs) Based on Pure and Copper-Foam-Loaded PCMs
In this work, a commercial paraffin PCM (RT35) characterized by a change range of the solid-liquid phase transition temperature Ts−l=29–36 °C and the low thermal conductivity λSL=0.2 W/m K is experimentally tested by submitting it to thermal charging/discharging cycles. The paraffin is contained in a case with a rectangular base and heated from the top due to electrical resistance. The aim of this research is to show the benefits that a 95% porous copper metal foam (pore density PD=20PPI) can bring to a PCM-based thermal storage system by simply loading it, due to the consequent increase in the effective thermal conductivity of the medium (λLOAD=7.03 W/m K). The experimental results highlight the positive effects of the copper foam presence, such as the heat conduction improvement throughout the system, and a significant reduction in time for the complete melting of the PCM. In addition, the experimental data highlight that in the copper-foam-loaded PCM the maximum temperature reached during the heating process is lower than 20K with respect to the test with pure PCM, imposing the same heat flux on the top (P=3.5 W/m2)
Advances in chromosomal studies in Neottieae (Orchidaceae): constitutive heterochromatin, chromosomal rearrangements and speciation.
Abstract — In this work, we describe a karyomorphological study on three taxa of the tribe Neottieae (Orchidaceae). Epipactis aspromontana and E. schubertiorum are characterized by a chromosome complement of 2n = 2× = 38. Significant differences in heterochromatin distribution were found between them. Similarities in the karyotype structure and C-banding of E. schubertiorum and E. helleborine group have been observed. A specimen of E. aspromontana showed a triploid chromosome number. The meiosis are characterized by univalent, bivalent and trivalent forms and in some somatic metaphase cells has been possible to observe a series of aneuploid numbers with 46, 47, 48, 49, 50, 51, 52 and 53 chromosomes. The largest differences can be emphasized between the Epipactis species and Neottia nidusavis, mainly in the the karyomorphology and heterochromatin distributions. In Neottia nidusavis the evolution process seems to be determined by reversing Robertsonian mutations
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