Showing papers by "University of Udine published in 1988"
TL;DR: In this article, shear stress and shear rate data obtained for cement pastes were correlated by means of different rheological models, including the Herschel-Bulkley model.
Abstract: Shear stress and shear rate data obtained for cement pastes were correlated by means of different rheological models. Pastes were prepared from a commercial Portland cement 325 at different water/cement ratios ranging from 0.34 to 0.42. Tests were performed at 25°C using a rotating coaxial cylinder viscometer. The investigation was accomplished by means of a hysteresis-cycles procedure. On the basis of the goodness of fit, the Herschel-Bulkley model seemed to be very effective for application to cement pastes.
78 citations
TL;DR: The aim of the experiments reported here was to establish whether the size-weight illusion was sensorial or was caused directly by an expectancy, and it was concluded that the illusion was of sensory origin.
Abstract: An important part of the literature on the size-weight illusion ascribes great importance to expectancies as determinants of the illusion itself. The aim of the experiments reported here was to establish whether the size-weight illusion was sensorial or was caused directly by an expectancy. In Experiment 3, which was the crucial experiment, subjects first looked at an object (from a 3×5, size x weight, factorial design), and then the object was hidden from view. Immediately after the object was hidden from view, the subjects lifted the object and rated its heaviness. It was expected that any possible motor set, or any perceptual or cognitive expectancy, should persist during the lifting. The size-weight illusion did not occur in Experiment 3. Therefore, it was concluded that the illusion was of sensory origin.
71 citations
TL;DR: In this paper, the stabilization of a pile of ground urban refuse was monitored during five months, and the humification index (HI) of organic matter extracted by 0.1 M Na4P2O7 plus 0. 1 M NaOH was found to decrease linearly with time during the thermophilic phase from about 1.4 to 0.4.
64 citations
TL;DR: In this paper, a new strategy for composting has been developed, based on O 2 feedback control, which seems to give satisfactory results in terms of process control, quality of end-product, low energy consumption, and hygienization of compost.
52 citations
TL;DR: In this paper, the humification index (HI) values of three different manures and earthworm casts were calculated for three different extractant solutions (0.5M sodium hydroxide, pH 7 and 0.1M NaOH).
Abstract: The humification index (HI) values of three different manures and earthworm casts were calculated for three different extractant solutions (0.5M sodium hydroxide, 0.1M sodium pyrophosphate pH 7 and 0.1M sodium pyrophosphate plus 0.1M NaOH). The alkaline sodium pyrophosphate solution was found to be the most suitable because of both its extraction efficiency and the quality of the organic matter extracted which allows a good characterization of the stabilization degree attained by composting. Neutral sodium pyrophosphate extracts also show characteristic HI values for different samples but lower extraction efficiencies. The HI values for sodium hydroxide extracts show only little differences between manures and composts. The good correspondence found between HI data and isoelectric focusing (IEF) patterns confirmed on one side that humification indexes give a quantitative measure of the humification degree, on the other side that IEF is a suitable technique in order to obtain qualitative informations on organic matter stabilization in earthworm casts.
44 citations
TL;DR: The anticooperative nature of the interaction is essentially polyelectrolytic in origin, and the structural results obtained from the daunomycin‐d[(CGTACG)]2 crystal suggest that the 2‐NH2 group of guanine might be responsible for such a phenomenon.
Abstract: The interaction of daunomycin with ctDNA and six purine–pyrimidine alternating poly-deoxynucleotides has been studied using fluorometric and uv-visible absorption methods. In the explored binding range of r > 0.05, the intercalation of the drug into the DNAs proved to be anticooperative, as indicated by the pronounced upward curvature of all the Scatchard plots obtained. The experimental data have been analyzed according to the recent theory of Friedman and Manning, which describes the polyelectrolyte effects on the site binding equilibria, drug intercalation included. We found that, accounting for the polyelectrolyte effects in the neighbor site exclusion model, the experimental data were nearly equally well described, in a wide range of binding ratios, by assuming the presence of sequence specificity effects (site size = 2 base pairs, exclusion parameter n = 1) or its absence (site size = 1 base pair, n = 1.7). The relevant results are as follows: (a) Daunomycin binds to all the DNAs considered with a stoichiometry of approximately 1 drug for every two base pairs. (b) The anticooperative nature of the interaction is essentially polyelectrolytic in origin. (c) The binding affinity shown by the drug for the different sites considered decreases in the order of Gm5C > AT > AC-GT > IC > GC > AU, indicating a stabilizing effect of the —CH3 group in position 5 of the pyrimidines. (d) The extent of quenching of the intrinsic fluorescence of daunomycin in the presence of DNA is bound to the presence, at the intercalation site, of a guanine residue, since GC, Gm5C, and AC-GT sites induce a nearly total quenching, whereas AT, AU, and IC sites act only partially in this respect. The structural results obtained from the daunomycin-d[(CGTACG)]2 crystal suggest that the 2-NH2 group of guanine might be responsible for such a phenomenon. The influence of both the temperature and the ionic strength on the free energy of drug intercalation into ctDNA, poly[d(G-C)] : poly[d(G-C)], and poly[d(A-C)] : poly[d(G-T)] is examined and discussed.
36 citations
TL;DR: In this paper, the authors evaluated variations in dressing percentage, carcass and meat quality, and fat composition in male Alpine kids with a view to increasing meat yield by changing slaughter weight.
35 citations
TL;DR: In this article, the approach suggested by Cheng and Evans has been taken into account in order to derive a constitutive equation capable for characterizing completely the flow behavior of white Portland cement pastes.
34 citations
TL;DR: In this article, the direct synthesis of ketimines from ammonia and ketones catalyzed by ammonium chloride was described, and the synthesis of a ketimine from ammonium is described.
32 citations
TL;DR: In this article, a Bhir horizon of a spodic soil and leonardite which, after electrofocusing, displayed bands in the neutral region of the pH gradient, were fractionated by electrophoresis in phosphate buffer at pH 6.5.
Abstract: SUMMARY
The alkaline extracts of an andic soil, a Bhir horizon of a spodic soil and leonardite which, after electrofocusing, displayed bands in the neutral region of the pH gradient, were fractionated by electrophoresis in phosphate buffer at pH 6.5. The non-migrated fraction gave an electrofocusing profile containing only bands focused at pH values above that of the electrophoretic separation. Electrophoresis in sodium acetate buffer pH 4.8 of humic substances extracted from peat permitted isolation of bands focusing above pH4.8. The distribution of metals after electrophoresis suggests that a great part of humic substances which originate bands above pH 6.5 consists of negatively charged Fe and Al complexes. Addition of EDTA to solutions of humic substances extracted from the samples resulted in the disappearance of bands in the neutral region of the pH gradient in the electrofocusing profile of the Bhir sample, while a consistent lessening of these bands was observed in the leonardite and andic soil samples.
32 citations
22 Aug 1988
TL;DR: This architecture proposes a novel concept of distributed problem solving, which incorporates in a unitary framework the following key-points; large-grained heterogeneous agents, centralized knowledge-based control, and mixed event-driven and goal-driven operation.
Abstract: The paper presents a distributed multi-agent architecture for natural language processing. This architecture proposes a novel concept of distributed problem solving, which incorporates in a unitary framework the following key-points; large-grained heterogeneous agents, centralized knowledge-based control, and mixed event-driven and goal-driven operation. It provides, moreover, a flexible tool for the design of natural language processing systems, both motivated from the cognitive point of view and computationally effective and robust. The proposed architecture has been implemented in a fully running prototype system, and has been successfully applied in the domain of text understanding.
TL;DR: In this article, the α-interferon (α-IFN) 3 MU per day for 3-6 months and then with 3 MU three times per week for at least 3 further months.
TL;DR: In this article, a finite-element procedure for the prediction of laminar forced convection in three-dimensional parabolic flows is presented, based on the parabolized simplification of the complete Navier-Stokes equations, and compared with the available literature data for thermally and hydrodynamically developing flows in flat channels.
Abstract: A finite-element procedure for the prediction of laminar forced convection in three-dimensional parabolic flows is presented. The procedure, based on the parabolized simplification of the complete Navier-Stokes equations, is first validated by comparing computed results with the available literature data for thermally and hydrodynamically developing flows in flat channels. Then, new results are presented for simultaneously developing flows in square duels, with $, and $ boundary conditions and Prandtl number ranging from 0.1 to 10.
TL;DR: In this article, the analyzing power of the Fermilab polarized proton beam was measured with use of the new 185-GeV/c FermILab polarized beam.
Abstract: The analyzing power ${A}_{N}$ in inclusive ${\ensuremath{\pi}}^{0}$ production has been measured with use of the new 185-GeV/c Fermilab polarized proton beam. We obtain the value ${A}_{N}=0.10\ifmmode\pm\else\textpm\fi{}0.03$ for ${\ensuremath{\pi}}^{0}'s$ in the kinematic region $0.2l{x}_{F}l0.8$ and $0.3l{p}_{T}l1.2$ GeV/c. In certain models of particle production this suggests that the spin of the proton is carried by its valence quarks.
TL;DR: In this article, the authors defined the class of natural Runge-Kutta methods and observed that it includes all the collocation methods and showed that it coincides with the projection methods in some polynomial spaces.
Abstract: Recently the author defined the class of natural Runge-Kutta methods and observed that it includes all the collocation methods. The present paper is devoted to a complete characterization of this class and it is shown that it coincides with the class of the projection methods in some polynomial spaces.
01 May 1988
TL;DR: The overall organization of the IR-NLI II system is presented, together with a short description of the two main modules implemented so far, namely the Information Retrieval Expert Subsystem and the User Modeling Subsystem.
Abstract: This paper addresses the problem of building expert interfaces to information retrieval systems. In particular, the problem of augmenting the capabilities of such interfaces with user modeling features is discussed and the main benefits of this approach are outlined. The paper presents a prototype system called IR-NLI II, devoted to model by means of artificial intelligence techniques the human intermediary to information retrieval systems. The overall organization of the IR-NLI II system is presented, together with a short description of the two main modules implemented so far, namely the Information Retrieval Expert Subsystem and the User Modeling Subsystem. An example of interaction with IR-NLI II is described. Perspectives and future research directions are finally outlined.
TL;DR: In this paper, the existence of solutions for a class of optimal design problems with respect to G-convergence has been studied, and a general integral representation theorem is obtained for the relaxed functional.
Abstract: The paper deals with the existence of solutions for a class of optimal design problems. The notion of relaxation of an integral functional with respect toG-convergence is introduced, and a general integral representation theorem is obtained for the relaxed functional. For a particular class of functionals, this integral representation is computed explicitly.
TL;DR: In this paper, an easy procedure for the preparation of electrodes coated by poly-2,5-pyridine is described, based on the electrochemical reduction of the corresponding dibromopyridine in acetonitrile catalyzed by the nickel-bipyridyl complex.
TL;DR: H2O2 was shown to reduce the copper ion of native bovine Cu,Zn superoxide dismutase and to oxidize the reduced enzyme and this result points to HO2- as the reactive species in both processes, and indicates that the electrostatic control of the access of the peroxide to the active site is the rate-determining step of the two redox reactions.
TL;DR: The existence of monomeric N-methyleneanilines is strictly related to the presence of enough steric hindrance to oligomerization by substituents in ortho positions.
Abstract: A convenient, high yield “dry” method of synthesis of monomeric N-methyleneanilines (6a—i) and the characterization of the products by m.s., 1H- and 13C-n.m.r. and i.r. are reported, improving previous procedures and describing new compounds. It appeared that the existence of monomeric N-methyleneanilines is strictly related to the presence of enough steric hindrance to oligomerization by substituents in ortho positions. Moreover, some addition products of formaldehyde to an amine and its corresponding imines are tentatively identified on the basis of the observed mass spectrum of the whole reaction mixture.
The reaction products of formaldehyde with 2,6-dimethylaniline (1a) provided an example of a mobile equilibrium between monomeric and trimeric imine.
TL;DR: In this article, the authors studied the duplex-hairpin conformational transition in two perfectly palindromic sequences, d(CGCGCGATCGC GCGCG)(I) and d(GCGCGCGTACGC GCG)(II), by means of UV-melting, electrophoretic and T-jump experiments.
Abstract: We have studied the duplex-hairpin conformational transition in two perfectly palindromic sequences, d(CGCGCGATCGCGCG)(I) and d(CGCGCGTACGCGCG)(II), by means of UV-melting, electrophoretic and T-jump experiments. Both tetradecamers exhibit biphasic thermal profiles. The lower temperature transition is concentration dependent whereas the higher temperature transition is not. The former transition has been characterized by gel electrophoresis and shows two distinct bands, whose intensity depends on temperature. This behavior is due to the occurrence of a slow premelting interconversion between the duplex and hairpin forms in both tetradecamers. The kinetics of hairpin formation from the duplex is studied by T-jump experiments. Relaxation spectra are well reproduced by a single relaxation time with rate constants characterized by a high temperature coefficient. In 10 mM NaCl, the duplex-hairpin conversion of I is characterized by an apparent activation energy of 96 +/- 6 kcal/mol, a value rather close to the expected denaturation enthalpy. In 1 mM NaCl a value slightly lower has been obtained. The rate of duplex-hairpin interconversion has been found to decrease as the salt concentration is raised. These data suggest that the transformation from the duplex to the hairpin form should imply a transition state with a simultaneous breaking of most base pairs, if not total strand separation.
TL;DR: A general notion of primitive iteration which subsumes the for-until-do construct as well as all known primative iteration operators is suggested, which leads to new iterative characterizations of primitive computable functions usable in computer science.
TL;DR: A very general class of Runge-Kutta methods for the numerical solution of Volterra integrodifferential equations and the development of the theory of Natural Continuous Extensions (NCEs), i.e. piecewice polynomial functions which interpolate the values given by the RK-method at the mesh points.
Abstract: In this paper we deal with a very general class of Runge-Kutta methods for the numerical solution of Volterra integrodifferential equations. Our main contribution is the development of the theory of Natural Continuous Extensions (NCEs), i.e. piecewice polynomial functions which interpolate the values given by the RK-method at the mesh points. The particular features of these NCEs allow us to construct tail approximations which are quite efficient since they require a minimal number of kernel evaluations.
TL;DR: In this article, shear stress and shear rate data obtained for gypsum plaster pastes were correlated by means of different rheological models and discrimination among the models was made: (1) on the basis of the fitting goodness; (2) by checking the physical meaning of the calculated parameters; (3) in the light of the stability of the parameters and of their prediction capacity beyond the limits of the experimental data.
Abstract: Shear stress and shear rate data obtained for gypsum plaster pastes were correlated by means of different rheological models. The pastes were prepared from a commercial calcium sulfate hemihydrate at various water/plaster ratios ranging from 100/150 to 100/190. The tests were performed at 25°C using a rotating coaxial cylinder viscosimeter. The measurements were accomplished by applying a step-wise decreasing shear rate sequence. Discrimination among the models was made: (1) on the basis of the fitting goodness; (2) by checking the physical meaning of the calculated parameters; (3) on the basis of the stability of the parameters and of their prediction capacity beyond the limits of the experimental data. In the light of above, the Casson model seemed to be most effective for application to gypsum plaster pastes.
01 Jan 1988
TL;DR: In this article, a nickel-catalysed electrochemical method for the synthesis of poly-2,5-pyridine is suggested, based on the reduction of 2,5dibromopyridine carried out by generating electrochemically and continuously recycling nickel(0) from nickel(II) in the presence of both bipyridyl and triphenyl-phosphine.
TL;DR: In this paper, le modele k-e is used to calculate les viscosites effectives and les conductivites thermiques in bidimensionnels de recirculation.
Abstract: Prevision de la convection forcee turbulente dans des ecoulements bidimensionnels de recirculation. On utilise le modele k-e pour calculer les viscosites effectives et les conductivites thermiques
TL;DR: In this article, the first experimental results demonstrating stochastic cooling of an ion cloud in a Penning trap were reported, and they were used to construct the first ion cloud model.
Abstract: First experimental results demonstrating stochastic cooling of an ion cloud in a Penning trap are reported.
TL;DR: In this paper, the authors showed that Nitric oxide reacts with [Co(PSR)2]-BF4 to form five-coordinate mononitrosyl {CoNO}8 complexes.