Determination of phthalate esters in wine using solid-phase extraction and gas chromatography–mass spectrometry

A method for the determination of six phthalate esters in wine samples has been developed. The phthalates were extracted from wine samples with an optimised solid-phase extraction method on C18 column and quantification was achieved via gas chromatography coupled with a mass spectrometer. The method was linear between 0.015 and 5.000 μg mL⁻¹ for DMP, DEP and DEHP and between 0.018 and 5.000 μg mL⁻¹ for iBP, DBP and BBP. The LOQs of DMP, DEP and DEH were 0.024 μg mL⁻¹ while those of iBP, DBP and BBP were 0.029 μg mL⁻¹. The intra-day method repeatability was between 10% and 15% RSD, whereas the inter-day method repeatability was between 13% and 21% RSD. A survey was performed on white and red wines (n = 62) from the market, winemakers and an experimental pilot plant. All the analysed samples were phthalate contaminated. Commercial wine showed higher detection frequency and level of total phthalate, DBP and BBP than those produced in a pilot plant. iBP and DEHP concentrations were similar in all the groups of samples. iBP concentration was higher in red wines than in white ones.     

The metabolic clearance rates and interconversion of cortisol and cortisone in pregnant and nonpregnant baboons

Pregnancy alters the pattern of maternal cortisol (F) metabolism and increases the maternal serum cortisol-binding capacity (CBC) of baboons. To determine whether these changes are associated with alterations in F clearance,the metabolic clearance rate (MCR) and interconversion (p) of F and cortisone (E) were measured by continuous infusion of (3H)F and (14C)E in 9 regularly menstruating and 7 pregnant baboons (Papio papio). In nonpregnant animals, the values (X +/- SE) for MCR-E (488 +/- 48 1/day) were greater (P less than 0.001) than those for MCR-F (214 +/- 22 1/day). The p value for the conversion of E leads to F (62.8 +/- 4.7%) was greater (P less than 0.001) than that for the reaction F leads to E (41.6 +/- 3.7%), indicating that F formation is favored. Consistent with MCR-E greater than MCR-F, the per cent of F bound to proteins other than albumin (75 +/- 2) was greater (P less than 0.001) than the per cent of E bound (52 +/-3). The production rate (MCR x peripheral concentration; mug/min) of F (55.1 +/- 7.9) was greater (P less than 0.001) than that of E (28.5 +/-3.9) with essentially all of the F being secreted directly (secretion rate 51.2 +/- 7.9 mug/min). Essentially all of the E produced was derived from circulating F, vitually none being secreted directly (secretion rate 4.6 +/- 3.9 mug/min). Pregnancy did not alter the MCR-F (190 +/- 23 1/day), MCR-E 525+/- 51 1/day), per cent of F (79 +/- 3), or per cent of E (49 +/-3) bound,or F (57.2 +/- 9.2 mug/min) or E (35.5 +/- 4.9 mug/min) production rates. CBC (mug F/100 ml) was significantly (P less than 0.01) elevated (25.3 +/- 2.3, nonpregnant vs 35.1 +/- u.6, pregnant). In addition, p E leads to F was increased (75.5 +/- 1.8%) as was p F leads to E (54.3 +/- 3.7%; P less than 0.01). We have concluded that the MCR-F during pregnancy is more dependent on alterations in maternal metabolism than on the increased serum CBC characteristic of gestation. We suggest that the latter factor may be important in regulating the physiologic levels of the other steroids which bind to it.     

A new type of biepitaxialc-axis tilted YBCO Josephson junction

A novel fabrication procedure of high critical temperature superconductor Josephson junctions (HTCSJJ) has been developed by a 90° rotation of YBa₂Cu₃O_7–x c-axis around an in-plane direction, on the basis of concepts of the biepitaxial technique. YBa₂Cu₃O_7–x grows oriented along (001) direction on a MgO seed layer deposited on a (110) SrTiO₃ substrate and along (110) direction on the bare substrate. Josephson junctions of good quality were obtained exhibiting RSJ behavior and features characteristic of HTCSJJ phenomenology. Even if not uniform, in some samples, the nature of the critical currentI _c is completely Josephson, as resulting from theI _c dependence on the applied magnetic field. The maximum measuredI _c R _N value atT=4.2K is 2mV.     

Evaluation of galvanic corrosion of a Zn alloy in alcohol fuel

Galvanic corrosion of zamak was evaluated in alcohol fuel and in some alcoholic solutions that contained ionic impurities. Also, the effect of corrosive process on the quality parameters of ethanol was investigated. The results showed that corrosion of zamak mainly occurred in solutions with high levels of water and impurities. After the assays, the increasing of both pH and conductivity of the alcohols was observed. Therefore, the results showed that the contact between zamak and some materials must be avoided and the quality control of alcohol fuel must be assured as a way of avoiding damages on engines and storage-transportation fuels systems.     

Waterborne acrylic-epoxy coatings

Waterborne two-component acrylic-epoxy coatings are gaining popularity as topcoats in moderate duty industrial and high performance architectural (HIPAC) applications. This increased popularity is due to their attractive handling, application, and performance properties, along with their low solvent content and odor. The objectives of this work were to characterize the cure and property development of these coatings, evaluate performance properties of cured films, and investigate a new epoxy resin dispersion in existing acrylic-epoxy formulations. These evaluations confirmed that existing acrylic-epoxy coatings have long pot life and short dry times while displaying a range of chemical resistance and physical properties. IR spectroscopy and differential scanning calorimetry (DSC) results indicated that the extent of cure at ambient conditions over a 21-day period was minimal; however, dynamic mechanical analysis (DMA) and solvent swell results did illustrate noticeable crosslink density development under these conditions. DSC results demonstrated more complete reaction and cure after heating. Direct substitution of a novel epoxy resin dispersion into these formulas resulted in lower required solvent content, shorter dry time, higher gloss, higher crosslink density, and improved water and scrub resistance. Presented at the 79th Annual Meeting of the Federation of Societies for Coatings Technology, on November 5–7, 2001, in Atlanta GA. 7201 Hamilton Blvd., MailStop R3108, Allentown, PA 18195-1501.     

On Sontag’s formula for the input-to-state practical stabilization of retarded control-affine systems

In this paper input-to-state practically stabilizing control laws for retarded, control-affine, nonlinear systems with actuator disturbance are investigated. The developed methodology is based on Artstein’s theory of control Lyapunov functions and related Sontag’s formula, extended to retarded systems. If the actuator disturbance is bounded, then the controller yields the solution of the closed-loop system to achieve an arbitrarily fixed neighborhood of the origin, by increasing a control tuning parameter. The considered systems can present an arbitrary number of discrete as well as distributed time-delays, of any size, as long as they are constant and, in general, known.     

Wet‐dry process of HCL removal from flue gas: experimental study on operating parameters

Wet‐dry process of hydrogen chloride removal from flue gas has been studied at pilot scale. Hot gas produced by methane burner, added with gaseous hydrogen chloride, is contacted by an aqueous suspension of calcium hydroxide in a cylindrical steel vessel 0.25 m I.D. and 4 m high.

The effects of feed ratio Ca(OH)₂/HCl, hydrogen chloride concentration in the inlet gas, operating temperature and residence time on the amount of hydrogen chloride removed have been exstensively investigated. The effect of inside wall fouling by Ca(OH)₂ has also been evaluated.

The experimental results show that the overall amount of hydrogen chloride removed increases when the feed ratio and the gas inlet concentration are increased and the operating temperature is decreased. However, the HCL removal does not seem affected by the residence time within the short interval investigated.