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- Author or Editor: M. G. Russo x
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Summary
We study a truncated interpolation process based on the zeros of the Markov--Sonin polynomials and give convergence results in some subspaces of the L p weighted spaces.
NH3 TPD study and thermal behaviour of vanadium-exchanged titanium phosphates as catalysts
Reduction of NO with NH3
The ion exchange technique was employed for the preparation of VO2+ modified titanium phosphates as catalysts for the selective reduction of NO with NH3. The samples were prepared by contacting with a vanadyl sulphate solution different precursor materials, amorphous, crystalline or sodium half exchanged titanium phosphate. The vanadium contents of modified phosphates were in the range 0.08–2.3 wt%. XRD and thermal analysis TG/DTA showed that vanadium loading does not cause structural modification in hydrogen titanium phosphate. A vanadyl containing phase was obtained when half sodium titanium phosphate was employed. The NH3 TPD measurements indicated the presence of a wide distribution of NH3 adsorbing sites with medium-high strength. Catalytic activity measurements were performed under dilute conditions. It was found that the presence of vanadium even in low amounts strongly promote the catalytic activity.
A wheat (Triticum turgidum L. var. durum) mutant, designated k-plus, constitutively possesses high leaf potassium content and light-green leaves. To study the genetic basis of these traits and to find out their association, k-plus mutant was crossed to the wild type (WT) Trinakria, F1 and F2 populations were developed. The flag leaves of parental lines, F1 and F2 progeny were assayed for ion content, at the heading stage. Potassium content was greater in k-plus than in WT; the F1 hybrids behaved like to the WT, in both potassium and leaf colour. The number of genes conditioning leaf potassium content, was not more than one, as estimated by Castle-Wright method. A single recessive locus controls potassium content of k-plus mutant, with the wild type allele completely dominant over the new mutant. Broad sense heritability can be considered sufficient to obtain progress from selection, of k-plus phenotype. Light-green leaf colour was inherited as monogenic recessive allele, which co-segregate with the locus controlling potassium accumulation. Light-green F2 sub-population had, on the average, significantly more potassium content than green F2 sub-population. These preliminary results encourage further physiologic and genetic analysis of k-plus mutant.
Abstract
Capillary electrophoresis has been used to separate metal ions characteristically associated with nuclear fission. Electrokinetic injections and transient isotachophoretic techniques were employed to increase sample loading and provide on-column concentration of the analyte. On-line concentration factors of approximately 700-fold have been achieved. Indirect-UV absorbance, on-line radioactivity, and indirect laser-induced fluorescence detection were used to monitor analytes of interest. The radioactivity detector consists of a plastic scintillator and photomultiplier tube with a 4π detection geometry. The efficiency was determined to be approximately 80%, enabling samples resident in the detector window for 0.1 minutes to be reliably assayed. Detection of152Eu and137Cs was achieved at the low nCi level. Indirect fluorescence was performed with quinine sulfate as the background fluorophor with α-hydroxysobutyric acid added as a complexing agent. An argon ion laser was used as the excitation source with a diode array detector. Limits of detection for La3+, Ce3+, Pr3+, Nd3+, Sm3+, and Eu3+ were determined to be in the sub — 10 ppb range (6–11 nM) with indirect laser-induced fluorescence detection.
Refuse derived fuels pyrolysis
Influence of process temperature on yield and products composition
Summary Refuse derived fuels (RDF) characterization and pyrolysis behaviour, carried out by means of thermogravimetric analysis, infrared and mass spectroscopy, are presented. Thermal degradation of RDF takes place through three main mass loss stages; the analyses of evolved gas allow us to discriminate the contributions of the different fractions (paper, LDPE, wood, rubber, etc.) to the global decomposition. Furthermore thermogravimetry (TG) was used for the determination of kinetic parameters, using the differential method. In order to set up the conditions of production of a good quality pyrolysis gas, the operating conditions of RDF in a pyrolysis reactor have been simulated. Data show that the volatile fraction grows with the temperature, together with the relative conversion, and that light volatile fraction (hydrogen, ethyne, etc.) gets richer, at the expense of superior homologous hydrocarbons.
Different osmotic agents (OA), such as potassium acetate (CH3COOK), potassium carbonate (K2CO3) and ammonium nitrate (NH4NO3), have been examined as alternatives to the traditionally used calcium chloride (CaCl2) for osmotic distillation concentrating of clarified and pre-concentrated sour cherry (Prunus cerasus L.) juice. Comparison of the process performances based on the permeate fluxes has been carried out. Regarding the permeate flux results, simplified estimation of the overall mass transfer coefficient of the most effective osmotic agent and the reference (CaCl2) solution has been also performed. Furthermore, analytical methods such as total antioxidant activity (TAA) and total polyphenolic content (TPC) using spectrophotometric assays have been also carried out to evaluate the effect of the osmotic distillation on the valuable compounds content of concentrated sour cherry juice. CH3COOK was found to be the most effective, resulted more than 25% higher permeate flux during the sour cherry juice concentration. K2CO3 and NH4NO3 were less effective. The simplified mass transfer estimation showed that the CH3COOK is more effective only at near saturated concentrations compared to the CaCl2. Regarding the TAA and TPC contents, a significant loss was found in case of all OAs during the concentration procedures.
