The Effect of Sulphur and Water Treatments on the Performance of Pd/��-Zeolite Diesel Oxidation Catalysts

Sulphur, sulphur-water, and water pretreatments were done to find out the effect of these compounds on a diesel oxidation Pd/??-zeolite catalyst and ??-zeolite washcoat. After pretreatments, the samples were analysed by BET, XRF, TEM-SEM, and XPS. In addition, the activity of fresh and pretreated Pd/??-zeolite catalysts was studied utilizing the by Gasmet FT-IR in production gas analysis. Sulphur compounds (SO₂ or ?SO₄) were found to have a deactivating effect on the activity of the studied Pd/??-zeolite catalyst.     

Cost modelling in underpinning projects

Large refurbishment projects are characterized by highly varied costs from one project to another. In Finnish underpinning, only retrospective analysis of costs has been available for the owner’s decision process. In order to develop tools for pre‐tender cost estimating and for comparison of different design solutions and evaluation of tenders of the underpinning project, two different cost models have been developed for research. In both models developed, the minimum data required is the pile length. In the more detailed model, the assessment is based on the design solution, including known pile types and the load transfer classification. Both models are easy to use, and the percentage of explained variance is fairly good in the more detailed model.     

Thermal analysis and topographical characterization of films of styrene-butadiene blends

Scanning probe microscopy (SPM) was used to study the thermal characteristics of latex films consisting of blends of two different styrene-butadiene copolymers with different glass transition temperatures (T_g). The resonance frequency (ω) and the quality factor (Q_p) of an SPM probe oscillating above the sample surface were determined at different probe temperatures (T_p). Thermal transitions associated with a change in heat capacity were observed in the Δω-T_p curves. The results were compared with differential scanning calorimetry measurements. The very slow heating rate used in the SPM method effectively eliminated the contribution of volumetric changes of the films around T_g. Annealing of the samples in an oven did not influence the thermal transitions observed in the Δω-T_p curves. The SPM method also enabled a novel approach for determining transition-induced dimensional changes (vertical contraction, expansion) of the films. Annealing was found to increase the dimensional stability of the blend films. The latex blends were also annealed by the SPM probe and the film progressed from particulate phase morphology to a continuous phase. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Social support and the quality of parenting under economic pressure and workload in Finland: The role of family structure and parental gender.

This study focused on how factors outside the home affect the quality of mothering and fathering. Economic pressure and workload were evaluated along with the compensating role of social support on parenting. Information was gathered from 842 mothers and 573 fathers including 139 single-mother and 21 single-father families. The results showed that the nature of the strains, together with parental gender and family structure, influenced their effects on parenting. The results further revealed some gender- and strain-specific protective functions of social support on parenting. For example, economic pressure was related to increased punitive parenting, which was compensated by instrumental and emotional support among the mothers. Workload was related to less authoritative single fathering, which was compensated by instrumental support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An Experimental and Computational Study on the Melting Behaviour of AOD and Chromium Converter Slags

The campaigns of the AOD and chromium converters are often limited by the strong wear of the refractory materials in certain areas (usually tuyere zone). Slag protection (in which the slag is left to solidify at the converter walls after the tapping of the metal) has been considered to be an option in prolonging the campaigns of the converters. In order to study the possibilities of the slag protection, the purpose of this work was to determine the melting behaviour of the AOD and chromium converter slags; i. e. the solidus and liquidus temperatures and the composition of solid phases as a function of temperature in different slag compositions. Examination was executed using both computational (FactSage software) and experimental (optical dilatometer/SEM) methods. It was noticed that when burned dolomite was added into the slags, the increased MgO‐contents had a strong influence on the melting behaviour. Even small changes (a few percent) in the MgO‐content had a very strong influence (a few hundred degrees centigrade) on the solidus and liquidus temperatures. Solid phases that are formed during the solidification are also different in slags with and without burned dolomite addition.     

Electric field imprinting of sub-micron patterns in glass-metal nanocomposites

We demonstrate that the dissolution of 10?nm metal nanoparticles localized in the subsurface layer of silicate glass by static electric field can be employed to alter the optical density and surface profile of the glass-metal composite with spatial resolution of 200?nm. The developed technique, which can be referred to as electric field imprinting (EFI), offers an attractive alternative to conventional micro-?and nano-pattering techniques.     

The Influence of Lubricating Agents on the Formation of a Film of a Styrene/Butadiene Latex

The interactions between paper coating lubricants and a carboxylated styrene/butadiene latex emulsion and their effect on latex film morphology have been studied. Calcium stearate, non-ionic polyethylene emulsion and organic triglyceride lubricants showed different interaction characteristics with the latex emulsion according to viscosity, zeta potential and isothermal calorimetric measurements. Calcium stearate lowered the viscosity of the dilute latex emulsion at low concentration suggesting a strong interaction with the latex particles due to a change in the hydrodynamic dimensions of the latex particles. The exothermic enthalpy change supported the assumption of a dissociative interaction. In contrast, both non-ionic polyethylene and organic triglyceride emulsion showed less pronounced enthalpy changes, indicating lower affinity for the latex particles. The reduction in viscosity showed, however, that at low lubricant concentrations there is an interaction between the latex particles and particularly the organic triglyceride emulsion. This suggests a selective adsorption of stabilizing agents and species from the lubricant emulsion which alters the hydrodynamic radius of the latex particles. The effects of the colloidal interactions on the morphology of the latex films monitored by Atomic Force Microscopy (AFM) indicated that specific surface interaction occurring in aqueous media influenced the topography and the surface chemical heterogeneity of the latex films. Especially in the case of calcium stearate, it seems that the dissolved species arrange themselves around the latex particles inhibiting film formation. The organic triglyceride, on the other hand, showed a lower interaction potential in the aqueous phase and it had a different impact on the film formation.     

Use of nanoparticular and soluble anionic celluloses in coagulation-flocculation treatment of kaolin suspension

In this work, the effectiveness of a novel, combined coagulation-flocculation treatment based on alum and soluble or nanoparticular anionic derivatives of dialdehyde cellulose, ADAC, was evaluated by studying the removal of colloidal material in a model suspension containing kaolin. Four different ADACs with varying degrees of substitution, size and water solubility were synthesized by periodate oxidation and sulfonation of cellulose. The effects of ADAC dosage, solution pH and temperature on flocculation were studied by measuring residual turbidity of the settled suspension. Moreover, the charge densities, sizes, ζ-potentials and stability of the ADACs in aqueous solutions were studied. The combined treatment was effective in the removal of colloidal particles, as demonstrated by reduced residual turbidity with remarkably lower total chemical consumption compared with coagulation with alum alone. Of the ADACs, samples with lower solubility that contained cellulose nanoparticles performed better than the fully water-soluble sample. Due to the restricted pH tolerance of alum, the combined treatment was effective only at acidic conditions (pH < 5), although the ADACs were found to be stable in a much broader pH range (pH of 3 to about 9). ADACs also retained strong activity at higher temperatures (30-60 °C) and after several days of storage in aqueous solution.