Showing papers by "Instituto Superior Técnico published in 1985"
TL;DR: A " working hypothesis" is discussed in terms of a "working hypothesis" for the mechanism of the [NiFe] hydrogenases from sulfate reducing organisms in the context of activation process and catalytic cycle.
135 citations
64 citations
TL;DR: Entrapped and adsorbed cells in polyurethane were able to degrade phenol up to 4g/l and 2.5 g/l respectively with no loss of their activity under repetead use for more than two months.
Abstract: The degradation of phenol by cells ofFusarium flocciferum immobilized by entrapment in agar, K — carrageenan, alginate and polyurethane, and by adsorption on preformed polyurethane foams was investigated. Entrapped and adsorbed cells in polyure —thane were able to degrade phenol up to 4g/l and 2.5g/l respectively with no loss of their activity under repetead use for more than two months.
52 citations
TL;DR: In this paper, two-and three-dimensional structures respectively composed of polygons and trivalent polyhedra, connected to give the minimum edge valency of vertices, are analysed from the topological and thermodynamic point of view.
47 citations
TL;DR: Octanoic and decanoic acids, byproducts of alcoholic fermentation, act in synergy with ethanol decreasing the maximum specific growth rate of Saccharomyces bayanus as an exponential function of its concentration as mentioned in this paper.
Abstract: Octanoic and decanoic acids, by-products of alcoholic fermentation, act in synergy with ethanol decreasing the maximum specific growth rate ofSaccharomyces bayanus as an exponential function of its concentration. Their presence, even at the low concentrations occuring in beer and wine, could partly explain the apparent higher toxicity of ethanol produced during fermentation as compared with added ethanol.
40 citations
TL;DR: The supplementation of a simple medium with soy flour led to an increase in the specific growth rate and viable cell concentration of Saccharomyces bayanus during fermentation and in the maximum number of viable yeast cells and the percentage of glucose fermented.
Abstract: The supplementation of a simple medium with soy flour led to an increase in the specific growth rate and viable cell concentration of Saccharomyces bayanus during fermentation. Increasing the amount of soy flour led to an increase in the maximum number of viable yeast cells and the percentage of glucose fermented. It was possible in 64 h to reach 12.8% (wt/vol) ethanol by adding 4% soy flour (wt/vol) to a simple medium with 300 g of glucose per liter. The aqueous extract from soy flour was nearly as effective as whole-soy flour, whereas the lipidic fraction had no positive effect.
36 citations
TL;DR: In this paper, the parent dinitrogen complex trans-ReCl(N 2 )(dppe) 2 ] with the appropriate ligand, in thf and in the presence of TlBF 4, was studied by cyclic voltammetry at a Pt electrode in [Bu 4 N][BF 4 ]/thf or acetonitrile; they undergo a one-electron reversible oxidation and the observed E OX 1 2 values were applied to test the validity of a proposed general expression derived from the electrochemical ligand (P L ) and 16-elect
36 citations
TL;DR: In this article, the effects of non-uniform mean flow on sound are demonstrated by comparing horns with nozzles, and 15 properties are proved and discussed, viz. relations between acoustic pressure and velocity; equipartition or biasing of kinetic and compression energies; conservation or evolution of wave action; existence of elementary or special solutions and cut-off frequencies, and amplitude and phase laws.
30 citations
TL;DR: In this paper, the authors developed an efficient algorithm for the computation of the shortest paths between given sets of points in the plane, when these paths are constrained not to cross any of a finite set of polygonal (open or closed) barriers.
27 citations
TL;DR: The supplementation of a simple medium with 2% soy flour increased the final ethanol concentration and the rate of fermentation by Saccharomyces bayanus and could not be attributed to an increase of ethanol tolerance of yeast cells but to the satisfaction of nutritional deficiencies.
Abstract: The supplementation of a simple medium with 2% soy flour increased the final ethanol concentration and the rate of fermentation bySaccharomyces bayanus. This improvement could not be attributed to an increase of ethanol tolerance of yeast cells but to the satisfaction of nutritional deficiencies.
21 citations
TL;DR: In this paper, excited state charge transfer interactions between zinc tetraphenyl-porphyrin and anthraquinone 2-sulphonate or duroquinone were studied in reversed micelles of dodecylammonium propionate and benzyldimethyl-n-hexadecylammium chloride (BHDC) as a function of the water content.
TL;DR: In this article, the rate of dissociation of cadmium with naturally occurring amino acids was studied at the ionic strength of seawater (0.70 M in sodium perchlorate medium) and at 25±0.1°C by differential pulse polarography and potentiometry with a glass electrode.
TL;DR: In this paper, the structure was solved by Patterson and difference Fourier electron density syntheses and refined to R (F )= 0.048 and R w (F) = 0.067 for 4763 observed reflections.
TL;DR: In this article, a modele fluide, including les collisions, le desaccord de frequence and la variation de masse relativiste, est etudie, and a transition vers le chaos peut se produire, conduisant a une disruption des ondes de plasma electronique.
Abstract: Etude des effets de saturation non lineaire associes a la generation des ondes de plasma electroniques par deux ondes electromagnetiques HF, battant a une frequence presque egale a la frequence du plasma electronique. Un modele fluide, incluant les collisions, le desaccord de frequence et la variation de masse relativiste, est etudie. Pour des ondes de grande amplitude, une transition vers le chaos peut se produire, conduisant a une disruption des ondes de plasma
TL;DR: In this paper, the concept of a cluster of faces in a polyhedron is introduced and used to distinguish between convex and non-convex straight polyhedra, according to the valency (number of dangling edges) of the clusters they contain.
TL;DR: In this paper, the representation of champs electromagnetiques a deux dimensions dans des structures planaires ouvertes is studied, and it is shown that le champ peut se representer exactement par une serie de fonctions appelees fonsctions de rayonnement.
Abstract: On etudie la representation de champs electromagnetiques a deux dimensions dans des structures planaires ouvertes. On montre que le champ peut se representer exactement par une serie de fonctions appelees fonctions de rayonnement
TL;DR: Acyl transfer from acetyl cyanide to either the oxygen of PhNHOH, the nitrogen of MeNHOMe, or the sulphur of PhCH2SH proceeds via tetrahedral intermediates that are readily detected by 1H and 13C n.m.r. spectroscopy as mentioned in this paper.
Abstract: Acyl transfer from acetyl cyanide to either the oxygen of PhNHOH, the nitrogen of MeNHOMe, or the sulphur of PhCH2SH proceeds via tetrahedral intermediates that are readily detected by 1H and 13C n.m.r. spectroscopy.
TL;DR: In this article, a semi-implicit scheme for the numerical solution of the shallow water equations is proposed, which is used for simulation of the major tidal component on the European Shelf.
TL;DR: In this article, the authors reported new measurements of the thermal conductivity of carbon tetrachloride in the temperature range 310 to 364 K at pressures up to 0.22 GPa.
Abstract: The paper reports new measurements of the thermal conductivity of carbon tetrachloride in the temperature range 310 to 364 K at pressures up to 0.22 GPa. The experimental data have an estimated uncertainty to ±0.3%. The hard-sphere theory of transport in dense fluids is employed to formulate a correlation scheme for the thermal conductivity as a function of density. A single equation represents the dependence of the thermal conductivity on density for all isotherms, the isotherms being distinguished by a characteristic value of the molar volume. It is shown that earlier measurements of the viscosity and self-diffusion coefficient of carbon tetrachloride may be represented in a similar fashion using consistent values of the characteristic volume.
TL;DR: In this article, a mixture of aminocarbyne complexestrans pluscis and hydridocompounds was shown to be possible with an alkylating agent.
Abstract: Treatment of complexestrans-[M(CNBu-t)2(dppe)2][(1) M = Mo or W, dppe = Ph2PCH2CH2PPh2] with protic acid gives a mixture of the aminocarbyne complexestrans- pluscis-[M(CNHBu-t)(CNBu-t)(dppe)2]+ (2) and the hydridocompounds [MH(CNBu-t)2(dppe)2]+ (3), whereas reaction with an alkylating agent (R+) appears to give the dialkylaminocarbyne compounds [M(CNRBu-t)(CNBu-t)(dppe)2]+ (4) also as a mixture of thetrans andcis isomers.
TL;DR: In this paper, a general framework is discussed within which a municipal authority can assess future needs for certain public services within its area and can develop a program for land purchase within a fixed budget.
Abstract: In this paper a general framework is discussed within which a municipal authority can assess future needs for certain public services within its area and can develop a programme for land purchase within a fixed budget. Concentration is on developing an optimising model, using mixed integer programming techniques, to identify available plots of land and to earmark them for specific land uses. A range of constraints is discussed, and a set of subsidies and penalties arising out of a solution method due to Balas, explained with reference to the local municipality of Coimbra in central Portugal, is presented.
TL;DR: In this paper, a kinetic study of n-hexane hydroisomerization was carried out in a dynamic reactor at 523 and 543 K, under a total pressure of 4MPa, nhexane pressures from 0.1 to 0.8 MPa and hydrogen pressures from 2.5 to 3.2 MPa on two PtHY catalysts either fresh or deactivated.
01 Apr 1985
TL;DR: The paper presents the general receiver structure, discussing it in the context of a specific example and showing that the receiver studied in this paper is a generalization of the cross-correlation receiver.
Abstract: Time delay determination is an important problem in numerous applications The approach taken here models the signals via linear differential equations driven by white noise The time delays are unknown parameters modulating the received signals The maximum likelihood estimation of the delays requires the filtering in the minimum mean square error (MMSE) sense of the signals The problem becomes that of the joint estimation of the signals with the identification of the delays Due to the structure of the signal model, the signal MMSE estimate is obtained via a recursive structure of the Kalman-Bucy type The class of signals considered includes the stationary signals, to which the cross-correlation receivers are restricted In fact, it can be shown that the receiver studied in this paper is a generalization of the cross-correlation receiver The paper presents the general receiver structure, discussing it in the context of a specific example The Cramer-Rao bound associated with the delay estimation is also discussed
TL;DR: The design philosophy of a new generation of automated controlers intended for the distribution network of Electricidade de Portugal (E.D.O.P.) is presented, which is built around a multi-task kernel which manages data acquisition and control functions, as well as man-machine interface.
01 Jan 1985
TL;DR: Solid-state batteries can be defined as power sources within which the transfer of the ionic species between the solid cathode or electronegative electrode, and solid anode, or electropositive electrode, occurs by migration through a solid electrolyte as opposed to a liquid phase as discussed by the authors.
Abstract: Solid-state batteries can be defined as power sources within which the transfer of the ionic species between the solid cathode, or electronegative electrode, and solid anode, or electropositive electrode, occurs by migration through a solid electrolyte as opposed to a liquid phase. These three active solid components are intimately involved in the electrochemical reactions which take place during discharge and, in secondary solid-state batteries, during charge.
TL;DR: In this article, a methode which met en relation le volume moyen v avec la longueur totale des bords L v and la surface totalale des faces S v par unite de volume and avec le nombre moyens de faces F par grain separe was proposed.
TL;DR: Isotopic thermal diffusion factors have been determined for krypton in the temperature range from 243.0 K up to 777.5 K as discussed by the authors, and theoretical comparison is reported for the exponential-six model and two sets of parameters are discussed.
Abstract: Isotopic thermal diffusion factors have been determined for krypton in the temperature range from 243.0 K up to 777.5 K. A theoretical comparison is reported for the exponential-six model and two sets of parameters are discussed. Some references are also made for several multiparametric models.
01 Jan 1985
TL;DR: The problem of delay estimation is considered and the estimator is conceptually equivalent to two blocks, which has the structure of a Kalman-Bucy filter for signals with delays and minimizes the log-likelihood function.
Abstract: The problem of delay estimation is considered. The approach taken generally considers nonstationary signals and correlated measurement noises. The signals are described as the output of a finite dimensional linear system driven by white noise. The estimator is conceptually equivalent to two blocks. The first has the structure of a Kalman-Bucy filter for signals with delays [9]. The second minimizes the log-likelihood function. When stationary, long observation interval (SLOT) [7] assumptions are considered, the cross-correlator array receiver [1] is recovered. The results of the paper are then a generalization of the classical solution.