4,426 research outputs found
Detailed analysis of quantum phase transitions within the algebra
We analyze in detail the quantum phase transitions that arise in models based
on the algebraic description for bosonic systems with two types of
scalar bosons. First we discuss the quantum phase transition that occurs in
hamiltonians that admix the two dynamical symmetry chains
and by diagonalizing the problem exactly in the
basis. Then we apply the coherent state formalism to determine the energy
functional. Finally we show that a quantum phase transition of a different
nature, but displaying similar characteristics, may arise also within a single
chain just by including higher order terms in the hamiltonian.Comment: 5 figure
Matched filters for coalescing binaries detection on massively parallel computers
We discuss some computational problems associated to matched filtering of
experimental signals from gravitational wave interferometric detectors in a
parallel-processing environment. We then specialize our discussion to the use
of the APEmille and apeNEXT processors for this task. Finally, we accurately
estimate the performance of an APEmille system on a computational load
appropriate for the LIGO and VIRGO experiments, and extrapolate our results to
apeNEXT.Comment: 19 pages, 6 figure
Cultivares de trigo Embrapa - i) resultados das unidades de observação, safra 2004, no RS, SC e PR.
bitstream/CNPT-2010/40552/1/p-co187.pd
Ammonia and Greenhouse Gas emissions from slatted dairy barn floors cleaned by Robotic Scrapers
The design of animal housing and manure management systems are key factors in livestock farming. Frequent removal
methods, in fact, allow for the reduction of gasses produced from fermentations of the organic matter contained in
manure, that affect animal welfare and farmer health and are emitted from animal housings into the atmosphere as a
consequence of ventilation. The present study aims to evaluate the performance of a Robotic Scraper (RS) operating on
the floors in a full-scale, operative free-stall dairy barn. The research is focused on the evaluation of gaseous emissions
from the two types of floors (concrete and rubber mat coated), and with and without RS operation. The floors with
rubber coating demonstrated higher emission rates of ammonia (NH3), carbon dioxide (CO2), nitrous oxide (N2O), and
methane (CH4) compared to the uncovered concrete floors, both before and after RS operations. The operation of RS,
furthermore, determined significant reduction of greenhouse gasses (GHG) but did not have relevant effect in terms
of NH3 emission, which reduced only of 1.4% from concrete floors, but increase of 12.7% from rubber coated floors
Boschi vetusti e riserve forestali nel Veneto: patrimoni di biodiversita\u300
Vengono sintetizzate le criticita\u300 emergenti legate alle dinamiche di cambiamento della biodiversita\u300 nelle foreste del Veneto anche esaminando i dati delle politiche forestali degli ultimi decenni e delle trasformazioni di boschi e foreste di montagna, collina e pianura conseguenti all\u2019abbandono colturale e ad iniziative locali di contrasto alle alterazioni del paesaggio forestale, di miglioramento ambientale ed estetico e di difesa della biodiversita\u300 forestale e naturalistica dei territori del Veneto.
Seppur in un confronto europeo l'Italia e\u300 forse uno degli stati piu\u300 virtuosi nella gestione del patrimonio boschivo, sia in termini di risparmio di biomassa (35% di prelievo sull'incremento contro la media europea di oltre 60%) che per modalita\u300 di prelievo (e\u300 uno dei pochi stati dove il taglio a raso e\u300 vietato e, a differenza di molti paesi europei, non ammette l'imboschimento con specie esotiche), in questo approfondimento vengono esaminati gli scenari possibili di riferimento per una programmazione piu\u300 mirata, incisiva ed innovativa delle politiche di tutela della biodiversita\u300 forestale del Veneto, guardando ad alcune esperienze europee volte alla tutela e valorizzazione dei boschi antichi o vetusti.
Boschi e foreste si stanno espandendo nel Veneto anche in pianura: ma questo trend e\u300 frutto dell\u2019abbandono colturale e/o conseguenza di una programmazione territoriale adeguata? Si propongono linee guida per iniziative locali di contrasto alla banalizzazione estetica ed ambientale del paesaggio e per contro di miglioramento della difesa della biodiversita\u300 forestale e naturalistica dei territori del Veneto partendo dalla tutela del patrimonio genetico dei \u201cboschi vetusti\u201d
Hyperthermic Perfusion 16 Years After its First Clinical Applications
It is known that above-normal temperatures (42°-42.5°C) provoke selective damage to neoplastic cells. We used heated circulating blood as a method for heat transfer on patients with limb tumors. From October 1964 to December 1979, we treated a total of 198 patients with hyperthermic perfusion for melanoma of the limbs (91), osteosarcoma (57), and soft tissue sarcoma (50). For melanoma patients, the five-year survival rate, excluding Stage IV, was 60%. For patients with soft tissue sarcoma, the five-year survival rates were 53% and 56% for hyperthermic perfusion and hyperthermic antiblastic perfusion. respectively. For 29 patients with osteosarcoma, hyperthermic perfusion was combined with systematic amputation ofthe limb for a 60% survival rate over a five-year period. Newer studies with osteosarcoma patients involve a multistep treatment that saves the tumor-bearing limb without reducing survival rates. Our 16-year clinical trial demonstrates that hyperthermia is effective in curing some tumors of the limbs, especially osteosarcoma and melanoma. We believe that perfusion remains the most reliable heat transfer method for loco-regional treatment and perhaps even for whole-body treatment for limb tumors
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