114 research outputs found
A formal theory of cubical complexes Formal report, 1 Sep. 1968 - 30 Apr. 1969
Algorithm for computation of test failures in cyclic circuit
Mineralogy and genesis of the kihabe Zn-Pb-V prospect, Aha Hills, Northwest Botswana
The Kihabe Zn-Pb-V > (Cu-Ag-Ge) prospect is located at the boundary between Namibia and Botswana (Aha Hills, Ngamiland District) in a strongly deformed Proterozoic fold belt, corresponding to the NE extension of the Namibian Damara Orogen. The Kihabe prospect contains Zn-Pb resources of 14.4 million tonnes at 2.84% zinc equivalent, Ag resources of 3.3 million ounces, and notable V-Ge amounts, still not evaluated at a resource level. The ores are represented by a mixed sulfide–nonsulfide mineralization. Sulfide minerals consist mainly of sphalerite, galena and pyrite in a metamorphic quartzwacke. Among the nonsulfide assemblage, two styles of mineralization occur in the investigated samples: A first one, characterized by hydrothermal willemite and baileychlore, and a second one consisting of supergene smithsonite, cerussite, hemimorphite, Pb-phosphates, arsenates and vanadates. Willemite is present in two generations, which postdate sulfide emplacement and may also form at their expenses. These characteristics are similar to those observed in the willemite occurrences of the nearby Otavi Mountainland, which formed through hydrothermal processes, during the final stages of the Damara Orogeny. The formation of the Kihabe willemite is likely coeval. Baileychlore is characterized by textures indicating direct precipitation from solutions and dissolution–crystallization mechanisms. Both processes are typical of hydrothermal systems, thus suggesting a hydrothermal genesis for the Kihabe Zn-chlorite as well. Baileychlore could represent an alteration halo possibly associated either with the sulfide or with willemite mineralization. The other nonsulfide minerals, smithsonite, cerussite, various Pb-phosphates and vanadates, are clearly genetically associated with late phases of supergene alteration, which overprinted both the sulfide and the willemite-and baileychlore-bearing mineralizations. Supergene alteration probably occurred in this part of Botswana from the Late Cretaceous to the Miocene
Polarization effects in the reaction and determination of the meson form factors in the time--like region
The electron positron annihilation reaction into four pion production has
been studied, through the channel . The
differential (and total) cross sections and various polarization observables
for this reaction have been calculated in terms of the electromagnetic form
factors of the corresponding current. The elements of the
spin--density matrix of the meson were also calculated. Numerical
estimations have been done, with the help of phenomenological form factors
obtained in the space--like region of the momentum transfer squared and
analytically extended to the time-like region.Comment: 19 pages, 2 figures, to appear in Phys Rev
Polarization effects in and determination of time like deuteron form factors
Polarization effects in the reaction have been
investigated for the case of longitudinally polarized electron beam and
arbitrary polarization of the produced deuteron, with the aim of a
determination of the time-like complex deuteron electromagnetic form factors.
General expressions of polarization observables are derived and numerical
estimations have been carried out by means of various models of deuteron
electromagnetic form factors, for kinematical conditions near threshold.Comment: 19 pages, 3 figure
L'ECHINOCOCCOSI IN SARDEGNA: UN'ESPERIENZA DI EDUCAZIONE SANITARIA NELLA SCUOLA DELL'OBBLIGO E VERIFICA DEL LAVORO SVOLTO
PRIMA INDAGINE SUL CURRICULUM DEGLI STUDI UNIVERSITARI DI STUDENTI E LAUREATI IN MEDICINA DELL'UNIVERSITA' DI CAGLIARI
Provvidenze a favore dei consorzi e delle societ\ue0 consortili tra piccole e medie imprese nonch\ue9 delle societ\ue0 consortili miste
VICENZUTTO D., PUTZOLU C., TASCA G. 2018, Tre dimensioni per un deposito archeologico: fotogrammetria 3D, potenzialit\ue0 informative e fruizione. Il caso studio della Gradiscje di Codroipo, in BORGNA E., CASSOLA GUIDA P., CORAZZA S., Preistoria e Protostoria del Caput Adriae, Atti della XLIX Riunione Scientifica dell'Istituto Italiano di Preistoria e Protostoria (Udine-Pordenone, 8-12 ottobre 2014), Firenze, pp. 697-702.
- …