Pseudo Diagram Research Articles

Phosphine-functionalized Fe3O4/SiO2/composites as efficient magnetic nanoadsorbents for the removal of palladium ions from aqueous solution: Kinetic, thermodynamic and isotherm studies

The aim of this study was to remove palladium ions from aqueous media in a batch operating system. A newly synthesized magnetic Fe3O4/SiO2/OPPh2 (diphenylphosphinite) nanocomposite was used as the adsorbent. This nanocomposite was examined by Fourier transform infrared, thermogravimetric analysis and X-ray spectroscopy methods. The factors that influence the adsorption equilibrium were examined, such as pH value, adsorbent dosage, metal concentration, adsorption time, temperature, influence of desorption solutions, concentration of the desorption solution and the influence of the ions present at the same time, namely Cd2 +, Ni2 +, Ca2 +, Co2 +, Fe3 +, Ba2+and Pt4+were determined based on the adsorbent used (Fe3O4/SiO2/OPPh2). Under optimal conditions and at the same concentrations, the interfering ions have only a very slight influence on the Pd (II) uptake. Finally, the first and second pseudo diagrams at temperatures of 20, 30 and 40 °C drew and the related value of R2 was calculated. As a result, we follow the second pseudo-diagram at 20 °C, the first pseudo-diagram at 30 °C and the second pseudo-diagram at 40 °C. The best fits at temperatures of 20, 30 and 40 °C were Generalized, Jossens, Fritz-Schlunder, and Weber-van Viel isotherm models respectively. It was found that the fit isotherm is the Fritz-Schlunder model. The best possible model was determined in advance on the basis of error functions. Thermodynamic parameters indicate the endothermic, irreversible and nonspontaneous nature of the adsorption. In addition, the useful application of the method presented was examined using the adsorption of palladium from the two different water samples.

Gauss diagrams, unknotting numbers and trivializing numbers of spatial graphs

In this paper we introduce Gauss diagrams and four kinds of unknotting numbers of a spatial graph. R. Hanaki introduced the notion of pseudo diagrams and the trivializing numbers of knots, links and spatial graphs whose underlying graphs are planar. We generalize the trivializing numbers without the assumption that the underlying graphs are planar. Finally we discuss relations among the unknotting numbers and the trivializing numbers.

Custom formulation of red ceramics with clay, sewage sludge and forest waste

The large quantities of sewage sludge that are currently generated require new alternatives for its recycling and final destination, beyond already known methods in the agriculture and cement industry. The use of this sludge as raw material for the production of structural ceramics, such as clay bricks, may become an interesting alternative, both from an industrial and environmental point of view. Several investigations have addressed this issue by formulating binary mixtures of sludge with clay. However, the incorporation of forest waste into the binary mixture described in this paper allows a high amount of sewage sludge to be assimilated into an extrudable mix and represents a better choice for the valorization of this hazardous waste. In this study the physicochemical properties of several formulations of ternary mixtures were analyzed. A ternary pseudo diagram was obtained relating the physicochemical properties of the ceramic product to the fraction of the raw materials. The optimal ternary mixture of 10% sludge, 10% forest waste and 80% clay, yielded a ceramic material with compression strength of 96 kp/cm 2. It also met the technological limit of 8 bar to give and extrudable material. The mixture would be suitable for building ceramics, with low thermal conductivity (0.31 W/m·K) and high porosity (59.4%). The environmental aspects of the production of these ceramics were investigated by leaching and outgassing tests.

Pseudo diagrams of knots, links and spatial graphs

A pseudo diagram of a spatial graph is a spatial graph projection on the $2$-sphere with over/under information at some of the double points. We introduce the trivializing (resp. knotting) number of a spatial graph projection by using its pseudo diagrams as the minimum number of the crossings whose over/under information lead the triviality (resp. nontriviality) of the spatial graph. We determine the set of non-negative integers which can be realized by the trivializing (resp. knotting) numbers of knot and link projections, and characterize the projections which have a specific value of the trivializing (resp. knotting) number.

Core polarization in coupled-cluster theory induced by a parity and time-reversal violating interaction

The effects of a parity and time-reversal violating potential, in particular the tensor–pseudotensor electron–nucleus interaction, are studied. We establish that selected terms representing the interplay of these effects and the residual Coulomb interaction in the coupled-cluster method are equivalent to the coupled-perturbed Hartree–Fock (CPHF). We have shown that the normal CPHF diagrams have a one-to-one correspondence in the coupled-cluster theory, but the CPHF pseudo diagrams are present in a subtle way. We have studied the pseudo diagrams in great detail and have shown explicitly their origin in the coupled-cluster theory. This is demonstrated by considering the case of the permanent electric dipole moment of atomic Hg, and our results are compared with the results of an earlier calculation.