177,466 research outputs found
Complex modes in boxed microstrip
No full textA method is described for obtaining the propagation coefficients and field patterns of a large number of modes for microstrip with a minimum of computational effort. The method uses a discrete space-domain formulation to calculate a large number of higher-order modes in a way which leads to their fast location and which ensures that node modes are missed. This includes those pairs of modes with complex conjugate propagation constants of the type reported for finline, as well as the normal evanescent modes. In addition, the characteristic impedance of microstrip is efficiently calculated. The results presented are obtained using the generally accepted power-current definition and are in agreement with other published result
Uomini e lavoro alla Olivetti
No full textIl volume è costituito da una serie di 25 autobiografie sotto forma di storie di lavoro alla Olivetti. Realizzate sotto forma di interviste, queste descrivono le vicende e i protagonisti di una grande impresa multinazionale italiana, la Olivetti, nelle sue trasformazioni di prodotti, di mercati, di strategie e strutture, ma anche negli avvicendamenti di proprietà e controllo, stile di direzione e di relazioni industriali, di culture aziendali. Olivetti infatti è un’impresa che nel corso del novecento si inserisce in diversi mercati internazionali e muta molte pelli: dalla meccanica di precisione (che l’aveva connotata sin dalla sua origine nel 1908) alla elettromeccanica tra gli anni quaranta e gli anni sessanta, dall’elettronica all’informatica tra gli anni sessanta e gli anni settanta, dalla tecnologia dell’informazione a quella delle telecomunicazioni tra gli anni ottanta e gli anni novanta.
Il focus delle interviste che costituiscono il volume si concentra in particolare sulla politica del personale che ha caratterizzato la grande stagione (e la grande eccezione) della Olivetti: una politica del “personale” che puntava alla gestione e allo sviluppo delle persone più che a preoccuparsi delle tecnicalità e degli specialismi della funzione oggi chiamata “risorse umane”.
Il libro può collocarsi però in una cornice più ampia della sola vicenda aziendale poiché attraverso di essa si può leggere sia il passaggio dell’impresa dalla forma funzionale e unitaria alla forma divisionale, sia il passaggio del capitalismo globale dalla forma tecnocratica alla forma proprietaria
A reappraisal of the Early to Middle Pleistocene Italian Bovidae
No full textDuring the Quaternary, bovids are common elements in the Italian local faunal assemblages (LFAs).
Representatives of Bovini tribe are continuously present, albeit with different lineages. Caprini are
sporadically recorded by several genera, and Antilopini are less represented, only during the Early
Pleistocene in the middle and early late Villafranchian local faunal assemblages (LFAs).
Diversity and ecological role of continental representatives of Italian Bovidae varied with LFAs as well
as in faunal units (FUs) throughout the Early and Middle Pleistocene. Species richness and diversity
peaked during the early late Villafranchian land mammal age (LMA) and then decreased in the post-
Jaramillo Early Pleistocene and at the beginning of the Middle Pleistocene (early and early middle
Galerian LMA). That time was characterized by the exclusive presence of bovids preferring open environments.
The small-sized bovids disappeared by the late Villafranchian, but a major renewal of the guild
took place at the transition from the Galerian to Aurelian LMA) (late Middle Pleistocene).
Endemic species are recorded in a few Italian islands: goat-like bovids with uncertain phylogenetic
affinity are recorded from the Late Pliocene to the Early Pleistocene in Sardinia, while subspecies of
Bovini, reduced in size, were present in Sicily during the Late Middle and Late Pleistocene and have been
claimed as present on the island of Pianosa (Tuscany
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Textile wastewater reuse in Northern Italy (Como)
No full textAn extensive research programme has been carried out on advanced treatment of secondary effluents discharged by centralized activated sludge treatment plants fed on mixed textile/domestic effluents in order to produce a final effluent suitable for reuse in the textile factories. Activated carbon adsorption or membrane filtration (ranging from microfiltration to reverse osmosis) have been investigated at pilot plant scale in order to determine the most economical and performing advanced treatment. The increase in concentration of refractory pollutants and of salts discharged in the final effluents because of water recycling within the textile processes have been evaluated by relevant mass balances. A techno-economical analysis on the proposed treatment is also presented.</jats:p
Biologically enhanced granulated activated carbon (BAC) filtration of a mixed industrial/domestic tertiary effluent for reuse
No full textBiologically enhanced granular activated carbon (BAC) is a promising wastewater post-treatment to produce a purified effluent suitable for recycle in the textile industry. Three small pilot scale filters were used, filled with three media (two adsorbent media and one non-adsorbent), to compare two different GACs and quantify the biomass contribution to organic removal and colour abatement. A demonstrative scale filter was tested in parallel to evaluate the influence of hydraulic parameters on BAC process efficiency. Biomass contribution was significant when an acclimated biofilm grew on particles; in all cases, wastewater decolorising was due to physical-chemical adsorption only; higher hydraulic load negatively affected the polishing process. Laboratory and semi-industrial scale tests were performed on textile fibres and fabrics using samples of the effluent from the demonstrative filter. The tests confirmed the suitability of the treated water for textile reuse.</jats:p
Experimental nephrotic syndrome in the rat induced by puromycin aminonucleoside: hepatic synthesis of lipoproteins and apolipoproteins.
No full textHepatic synthesis of lipoproteins and apolipoproteins was investigated in male Wistar rats with severe nephrotic syndrome induced by puromycin aminonucleoside by incubating liver slices with a mixture of 14C-amino acids. Labeled lipoproteins were separated by preparative ultracentrifugation from the incubation medium after the addition of carrier plasma. The incorporation of 14C-amino acids into very low density lipoproteins (VLDL) (1.006 g/ml), low density lipoproteins (LDL) (1.006-1.063 g/ml) and high density lipoproteins (HDL) (1.063-1.210 g/ml) was increased in nephrotic liver 6.1-, 5.7- and 5.0-fold, respectively. The measurement of radioactivity associated to apolipoproteins isolated by SDS-PAGE documented an increased incorporation into apolipoprotein E (apoE) of nephrotic VLDL (33.1% vs 20% of the total radioactivity incorporated into VLDL apoproteins) and a markedly increased incorporation into apolipoprotein A-I (apo-A-I) of nephrotic HDL (44.3% vs 16.3% of the total radioactivity incorporated into HDL apoproteins). In nephrotic liver, the total incorporation of amino acids into apolipoproteins (apoVLDL + apoLDL + apoHDL) was increased 12.6 times for apo-A-I, 6,4 times for apoB, 5.0 times for apoE, 4.2 times for apoC + apoA-II and 2.5 times for apoA-IV. We suggest that, in nephrotic liver: (a) the synthesis of VLDL, LDL and HDL is increased, and (b) the total synthesis of apoA-I is selectively increased when compared to that of the other apolipoprotein
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