Chain conditions on \textit{BL}-algebras

The aim of this paper is to solve the open problem appeared in Motamed and Moghaderi (Soft Comput 2012), about the relation between Noetherian (Artinian) $\textit{BL}$ -algebras in short exact sequences. Also, a better theorem to improve its results is suggested. The relation between Noetherian and Artinian $\textit{BL}$ -algebras is found, the concept of length for a filter in $\textit{BL}$ -algebras is introduced and properties of finite length $\textit{BL}$ -algebras are developed. Finally, it is proved that any $\textit{BL}$ -algebra has finite length if and only if be Noetherian and Artinian.     

Electrodeposition of catalytically active nickel powders from sulphate baths. I. Effect of bath constituents

A detailed study was made of the influence of the sulphate bath constituents: 0.3 - 0.0125 NiSO₄·7H₂O (I), 0.05 – 0.23 (NH₄)₂SO₄ (II), 0.1 – 0.4 H₃BO₃ (III) and 0.07 – 0.35 mol l^?1 Na₂SO₄·10H₂O (IV) on the electrodeposition of nickel powder. The cathodic polarization, current efficiency, growth morphology, crystallite size and catalytic activity of the electrodeposited nickel powders were affected to different extents by the bath constituents. A highly pure nickel powder characterized by a small crystallite size (776 Å) and moderate catalytic activity was obtained from a bath containing: 0.0125 (I), 0.23 (II), 0.1 (III) and 0.07 mol l^?1 (IV) at a current density of 10 A dm^?2 and electrolysis time 60 min. at 25 °C. Structural studies with a scanning electron microscope are given and a reaction mechanism for the electrolytic powder deposition is discussed.     

Polymerization of ethyl methacrylate,methyl methacrylate,and vinyl acetate using sulfonated polystyrene as the initiator

Polymerization of ethyl methacrylate (EMA) and methyl methacrylate (MMA) was achieved in glass dilatometers, at 86°C, using polystyrene sulfonate (Na⁺ and H⁺ forms) as initiators. The conversion of EMA to PEMA and MMA to PMMA increased with the time of polymerization, quantity of initiator, and size of dilatometer but decreased with volume of water. The polymer yield was higher for the Na⁺ than for the H⁺ form of the resin initiator. The average degree of polymerization increased with increase in the volume of water, but decreased with the quantity of initiator. Vinyl acetate could not be polymerized using either the Na⁺ or H⁺ forms of the polystyrene sulfonate as the initiator under the conditions of EMA or MMA polymerization.     

Behavior of cellulose graft copolymer towards persulphate oxidation. III. Poly(acrylonitrile) graft copolymers

Cotton cellulose was graft copolymerized with poly(acrylonitrile) to different levels. The copolymers so obtained together with the nongrafted cellulose were oxidized at different pH's (4–10) and temperatures (50–70°C) with potassium persulphate. The oxidation reaction was studied with respect to oxygen consumption, mass loss, and changes in copper number and carboxyl content of the cellulosic materials. It was found that the rates of oxidation at pH 4 for the copolymers are substantially higher than that of the nongrafted cellulose and the rate of oxidation is higher the higher the level of grafting. The reverse is the case at pH 10. The mass loss increases as the oxygen consumption increases irrespective of the substrate used and the pH employed. The magnitude of the mass loss is substantially lower in the case of grafted cellulose than in the case of nongrafted cellulose. The cellulosic copolymers with higher graft levels show lower mass loss than those having lower graft levels. However, the copper number and carboxyl content of the oxidized grafted cellulose are higher than those of the nongrafted cellulose at the same oxygen consumption. It is believed that the presence of poly(acrylonitrile) graft in the molecular structure of cellulose impedes cellulosic chain scission without necessarily preventing oxidation of cellulose hydroxyls.     

Analysis of deformation processes in glassy polycarbonate using internal friction measurements during a tensile test

Internal friction has been measured by torsion at 1 Hz during tensile tests performed on glassy polycarbonate at room-temperature. Steady-state flow and transient effects have been studied during continuous tensile tests and strain-rate changes. During steady-state, internal friction and flow-stress vary in a similar way with strain-rate. But during transients, internal friction varies continuously while flow-stress passes through a maximum (or a minimum). These results are interpreted assuming that non-elastic deformation of glassy polymers requires some microscopic discontinuous processes such as motion of defects. Two parameters are considered: the velocity v and the density ρ of mobile defects. Assuming that the former is directly related to the flow stress, it has been shown that internal friction is related to the density of mobile defects ρ. This feature is used to interpret the different stages of a tensile test curve. Activation volumes for both velocity and density of mobile defects are calculated from experimental data.     

Effect of EFA deficiency on lipid transport from liver

Studies are reported of the effect of an essential fatty acid (EFA) deficiency on synthesis of triglycerides (TG) and phospholipids (PL) and secretion of these compounds by livers of male Sprague-Dawley rats. Animals were fed a semipurified diet containing corn oil or hydrogenated coconut oil (HCO) as the sole source of fat or no fat from weaning to 20 weeks of age. Liver function of the animals in each group was compared by an isolated liver perfusion technique with perfusates containing erythrocytes and linoleate, and in vivo experiments via tail vein injection of palmitate-³H. Perfusion experiments showed that an EFA deficiency reduced the ability of the liver to secrete TG and PL. Accumulation of TG in the liver and its diminished secretion into the blood of EFA deficient animals were demonstrated by in vivo experiments with palmitate-³H. The rate of conversion of linoleate to arachidonate and synthesis of PL was greater in livers of EFA deficient rats than in the control, corn oil fed animals. The results suggest a relationship of EFA metabolism to lipid transport. One of five papers to be published from the Symposium “Lipid Transport” presented at the AOCS Meeting, New Orleans, April 1970.     

Constrained regression in chemical engineering practice

Absolute equality constraints in multiple regression are shown to introduce only minor modifications in the normal equations by a subset of the regression parameters. It is essential that these are ordered such that the subset is observable through the constraints. The constraints are shown to give greater residuals about the regression, but the precision in the parameter estimation is improved.In general power function curve fitting, a quadratically convergent iterative computation of the optimal exponents uses the normal equations as equality constraints. The correlations between the coefficients and the exponents in a sum of power functions become very high, when the number of terms increases such that their individual observability is being greatly reduced. The effect is shown to be a very poor precision in the parameter estimation and a heavy oscillation in the coefficients.The algorithms suggested are illustrated by curve fitting of some binary equilibrium data, where the relative volatility model gives a superior fit to the data.     

Homogeneous Catalyzed Ozone Decomposition in the Presence of Co(II).

The homogeneous decomposition of ozone in the presence of a Co(II) catalyst has been investigated in aqueous solution. Under the conditions investigated (Co(II) concentration: 0.0 – 2.0?ppm, pH: 1.6- 8.4, O₃ concentration: 5 10^?5 – 2.0 10⁴?M) the process can be assumed to follow pseudo first order kinetics with respect to ozone. Cobalt concentration dependency also obeys first order kinetics although it may be considered to reach a steady state concentration. pH exerts a positive influence on the decomposition rate from 1.6 to 7.1, the process leveling off at pH 8.4. An Arrhenius analysis of the temperature effect gave a moderate activation energy of the global reaction (E=10917?cal mol^?1). A more detailed radical mechanism than a simple pseudo first order reaction can be postulated for simulation purposes. By numerical optimization of some unknown kinetic constants the influence of several operating variables can be adequately predicted.     

Foamed nitride-bonded silicon carbide refractories

Conclusions We obtained foamed silicon carbide insulating material with a nitride bond. The nitride bond is formed from a mixture of silicon nitride of the- and-modifications upon reaction with nitrogen. The formation of the nitride commences at about 1200°, and is practically complete at 1450°; the rate of nitriding of the foam ceramic is much greater than in dense specimens. The material has a homogeneous phase composition which is an advantage compared with foamed silicon carbide containing a complex bond obtained in carbon fillings.The foamed insulating brick based on nitride bond possesses a high thermal-shock resistance and structural strength at elevated temperatures. The strength is increased with an increase in the apparent density. The material is characterized by moderate mechanical strength, typical for silicon carbide refractories of this type [1, 3, 4].The foamed silicon carbide brick with a nitride bond can be recommended for service at high temperatures in nonoxidizing atmospheres when substantial thermal-shock resistance is required.Translated from Ogneupory, No. 7, pp. 48–51, July, 1970.     

Double-layer nonswirl nozzles for continuous casting machine pony ladles

Conclusions A method for chamotte nozzles with protection of the bore with a zirconia concentratebase layer has been developed. The life of the nozzles with the protective layer is at least as good as the zirconia-graphite ones. It is desirable to use the double-layer nozzles in place of zirconia and zirconia-graphite nozzles in teeming of various types of steel.The consumption of zirconia concentrate per unit of product is reduced by 10–12 times, which opens prospects of a significant increase in the volume of production of this new form of parts.Translated from Ogneupory, No. 1, pp. 54–56, January, 1986.