ABSTRACT
The paper reports on some experimental results obtained from the production of ceramics containing steel slag and glass cullet from exhaust energy saving lamps mixed in different proportions. Blending of components was done by attrition milling. Pressed powders were fast fired (50 min, cold to cold) in air up to several temperatures in the range 1000-1140 degrees C. The sintering behaviour was studied by shrinkage and water absorption measurements. Density, strength and hardness of the fired bodies were determined and XRD were examined. The fired samples were finally tested in acidic environment in order to evaluate their elution behaviour and consequently their possible environmental compatibility. It is observed that the composition containing 60 wt.% of steel slag and 40 wt.% of glass cullet displayed the best overall behaviour.
Subject(s)
Ceramics/chemistry , Glass/chemistry , Industrial Waste , Metallurgy , Steel/chemistry , Waste Management/methods , Conservation of Natural Resources/methods , Hot TemperatureABSTRACT
The paper describes results obtained in the development of a previous research. We study here, in fast firing, the sintering behaviour and measure some properties of tiles containing a mixture of 60 wt% of paper mill sludge and 40 wt% of glass cullet. The behaviour of this material is compared to those displayed by materials obtained by the same mixture added with 10, 20 and 30 wt% of a natural red clay. In parallel, the same properties are measured also on a reference blend, which is presently used to produce commercial tiles. We show that powders containing 60 wt% of paper sludge and 40 wt% of glass cullet to which 30 wt% of clay is added give rise to materials that display a stable sintering process and have good hardness and strength and therefore could be used for the industrial production of tiles.
Subject(s)
Aluminum Silicates/chemistry , Construction Materials/analysis , Industrial Waste , Paper , Waste Management/methods , Clay , Glass , Hardness , Hot Temperature , Tensile StrengthABSTRACT
A high-performance liquid chromatographic method for the simultaneous determination of magnesium ascorbyl phosphate (I), imidazolidinylurea (II), a mixture of methyl-(III), ethyl-(IV), propyl-(V), butyl-(VI) parabens dissolved in phenoxyethanol, and ascorbyl palmitate (VII), was studied by using a cyano-propyl column and a methanol gradient at 220 and 240 nm. Calibration curves were found to be linear in the 0.05-5 mg ml(-1) range (compounds I, II, VII) and 0.9-160 mg ml(-1) (compounds III-VI). Linear regression analysis of the data demonstrates the efficacy of the method in terms of precision and accuracy. An extraction method is developed and validated in order to apply this chromatographic method to a commercial cosmetic cream. The precision of this method, calculated as the relative standard deviation (RSD) of the recoveries (1.57-2.21%) was excellent for all compounds I-VII.
Subject(s)
Chemistry Techniques, Analytical/methods , Cosmetics/chemistry , Ointments/chemistry , Ascorbic Acid/analogs & derivatives , Ascorbic Acid/analysis , Calibration , Chromatography, High Pressure Liquid , Parabens/analysis , Reproducibility of Results , Spectrophotometry, Ultraviolet , Urea/analogs & derivatives , Urea/analysisABSTRACT
The polydeoxyribonucleotide (PDRN) fraction is an extract which forms the active component in a new formulation of the drug Placentex (a tissue repair stimulating agent), obtained from human placenta through an original proprietory extraction method. From a comparison of the UV, NMR and IR spectra of this fraction (before and after nuclease treatment) with that of a similar standard (Sigma D1501), it was shown that the active substances in the PDRN fraction mainly consist of a mixture of DNA fragments. By gel electrophoresis, the molecular weights of the DNA fragments were shown to range from 50 to 2000 base pairs. Finally, an HPLC method is described, based on an anion-exchange material capable of determining the amount of PDRN in different batches of the extract, which varied from 80 to 90%.
Subject(s)
Placental Extracts/analysis , Polydeoxyribonucleotides/analysis , Chromatography, High Pressure Liquid/methods , DNA/chemistry , Humans , Molecular Weight , Placental Extracts/chemistry , Polydeoxyribonucleotides/chemistry , Reproducibility of ResultsABSTRACT
About 1 of every 50 women of child-bearing age who have a functioning kidney transplant become pregnant. Successful pregnancies following kidney allotransplantation with conventional immunosuppressive treatment are well described, and there is no evidence of abnormalities in the infants born. The use of cyclosporine (CSA) means new problems for the pregnant women and the fetus: the risk of congenital abnormalities, fetal growth retardation, hepato- and nephrotoxicity. We report the experience of 16 pregnancies in 16 of our kidney transplant patients, of which 7 were treated with CSA.
