Inhibition of nitrification in the packed bed reactors by selected organic compounds

The effect of methanol, acetone, formalin and glucose on the nitrification process in the packed bed reactors has been investigated. For the utilized compounds the inhibition constant K_i was determined according to Dixon's method. The determined values were as follows: methanol K_i = 116.0 mg l^?1; acetone K_i = 804.2 mg l^?1; formalin K_i = 61.5 mg l^?1. The value of K_i for glucose has not been determined because glucose in applied concentration up to 11,325 mg l^?1 had no effect on the nitrification course.     

Characterization of supported Pd-Pt catalysts by chemical probes

The temperature programmed (palladium) hydride decomposition appeared very effective method for diagnosing the extent of alloying in Pd-Pt/SiO₂ catalysts. Introduction of Pt to Pd catalysts moves the TPHD peak gradually towards lower temperatures and the shift in hydride decomposition peak is accompanied by a decrease in the amount of released hydrogen. The catalysts prepared the direct redox method showed much better alloy homogeneity than the samples prepared by coimpregnation. The results of probing with other techniques, i.e. catalytic probing with hydrodechlorination of CCl₂F₂ and XRD, were in line with TPHD data. The catalytic probing showed the presence of synergistic effect, a clear indication of Pd-Pt mixing. XRD data of post-reaction samples showed carbon incorporation into Pd-rich phase, whereas separate Pt-rich phase did not experience any bulk carbiding.     

Ion sputtering and its biomedical applications. Theoretical concepts and practical consequences. Clinical implications and potential use

It is the purpose of the paper to promote the ion beam sputtering technique and its biomedical applications among not only ion beam users but also other research workers, and especially, among biologists and medical doctors. The objectives of this article are threefold. Firstly, it supplies a conceptual background for discussing the main question of this work, i.e. biomedical applications of sputtering. Secondly, the title issue and some related problems, important in the biomedical use, are widely presented and discussed. Finally, clinical implication and potential applications are shown.     

Spectroscopic EPR and IR studies of monomeric and dimeric species formed upon adsorption of nitric oxide on Ce0.75Zr0.25O2 and their reactivity with dioxygen

The interaction of nitric oxide with Ce_0.75Zr_0.25O₂ solid solution were investigated by means of EPR and IR spectroscopies. The influence of adsorption parameters such as adsorption temperature and pressure, presence of the O₂ co-reactant on the nature and relative surface abundance of the resultant mono- and dimeric NO species was elucidated. The thermal stability of the surface nitrosyl complexes and their reactivity toward dioxygen were also examined.     

Transfer efficiency for airless painting systems

Spray transfer efficiency (TE) is defined as the mass fraction of sprayed paint which is deposited on the intended target, the remainder of the sprayed paint becomes undesirable overspray. The relationship between TE and gun supply pressure (or paint mass flow rate), gun-to-target distance, gun traverse speed, the angle of the spray gun relative to the target (gun-to-target angle), plus spray cone angle is reported herein for a typical fan spray system. Experimental results indicate that spray momentum rate (SMR) and droplet size dictate the TE for the various combinations of parameters considered here. The key finding is that TE correlates with SMR and spray mean drop size (Sauter mean diameter, or D₃₂) via an expression of the form TE=a+b SMR − c (SMR)²+d D₃₂, where a, b, c, and d are coefficients, determined by fitting the experimental data, and SMR is estimated via SMR=m²/ρA, where the paint mass flow rate m, the paint density is ρ, and the gun exit orifice effective tip cross sectional area is A. This expression accounts for physical phenomena that govern sprayed droplet deposition characteristics, such as entrainment, bounce-back, and drop size. Experimental results also show that, for the range of parameters studied, gun traverse speed has no effect on TE, but increasing the angle of the spray gun relative to the target (gun-to-target angle), increasing the spray cone angle, or increasing the gun-to-target distance will decrease TE.     

EPR Study of CO Adsorption onto CoZSM-5 Zeolite: Evidence for Spin Crossover upon Coordination and |z2, 2A1〉 Ground State

Adsorption of CO onto dehydrated cobalt-exchanged ZSM-5 zeolite was studied by CW-EPR techniques. It is shown that the reversible formation of a low spin carbonyl ¹{Co(CO) _n }⁷ adduct upon addition of carbon monoxide at p _CO>50–60 Torr involves significant change in the spin state of Co²⁺ from S=3/2 to 1/2. The spin Hamiltonian parameters of the adduct g _x =2.222, g _y =2.184, g _z =2.011, |A _x |=3.8 mT, |A _y |=3.2 mT, |A _z |=7.9 mT were determined by a computer simulation and further discussed in terms of the possible ground state and molecular structure. It is shown that the ¹{Co(CO) _n }⁷ cage complex exhibits a C_2v symmetry with |z ²,²A₁ ground state.     

INSIGMA: an intelligent transportation system for urban mobility enhancement

Intelligent Transportation Systems (ITS) aim to improve safety, mobility and environmental performance of road transport. The INSIGMA project provides a fresh look at the possible innovations in this field, by enhancing the functionality and accuracy of ITS in urban environments. This paper describes the architecture, sensors, processing algorithms, output modules and advantages of the developed system. A comparison of existing ITS systems has been provided as background. Special attention has been given to performance and privacy issues, as the system includes social aspects such as location monitoring.