Improved corrosion protection of aluminum alloys by electrodeposited silanes

Organofunctional silanes recently have emerged as outstanding, environmentally friendly corrosion protectors for metal substrates, compared with conventional chromate treatments. A simple immersion technique is typically used to coat the metal surface with silane films. However, the thickness and uniformity of the films are uncontrolled in this process. This paper proposes a new deposition technique for the silane films on the metal surface, i.e., by electrodeposition. Hydrolyzed silanes are water-soluble, ionized molecules, so they can be deposited on metals by electrodeposition. Various combinations of silane mixtures were tested at different voltages, pH values, bath concentrations, and exposure times on panels of alloy aluminum and mirror-polished ferro-plate. The surface structure was characterized by scanning electron microscopy (SEM) and ellipsometry. The resistance of the film to corrosion was investigated by direct current (DC) polarization and electrochemical impedance spectroscopy (EIS) techniques. Electrodeposition results in a more organized and uniform film with fewer pores, compared with immersed or dipped films. This paper was presented at the 2nd International Surface Engineering Congress sponsored by ASM International, on September 15–17, 2003, in Indianapolis, Indiana, and appears on pp. 320–26 of the Proceedings.     

Hydrogenation of unsaturated fatty esters during isobutane chemical ionization mass spectrometry

Hydrogenation of double bonds was observed to occur during the isobutane chemical ionization mass spectrometry (MS) of unsaturated fatty esters. Chemical ionization (CI) spectra of a series of methyl esters in the C16–C20 carbon range containing 0–4 double bonds showed a variety of ionization characteristics in the molecular ion cluster, including hydride abstraction, charge exchange, protonation and, for the unsaturated fatty acids (FA), hydrogenation of the double bond followed by protonation. The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Monomer and amino resin modified tall oil fatty acid alkyds

Summary Monomer modified tall oil fatty acid trimethylolethane medium type of phthalic alkyds made by the High Polymer Alkyd Technique show improved properties in dry time, mar resistance, and flexibility as compared with monomer modified conventional prepared systems. Greater hardness, less color degradation, greater resistance to extended periods at high temperature, and alkali and detergent resistances result from the urea and melamine resin modifications of tall oil fatty acid High Polymer alkyds than is obtained with similarly modified conventional alkyds.     

Aplysia sea hare assimilation of secondary metabolites from brown seaweed,Stypopodium zonale

JuvenileAplysia dactylomela were found feeding in abundance on the tropical brown algaStypopodium zonale, a seaweed previously shown to contain numerous unique terpene-quinone natural products. Lipid extracts of these herbivorous mollusks were shown by TLC and HPLC-NMR analyses to contain appreciable quantities of twoS. zonale metabolites as well as one new but closely related compound. Spectroscopic analyses of the new compound in concert with functional group modifications identified this new compound as 3-keto epitaondiol. A careful analysis of the seaweed extract failed to locate this ketone, and thus, it most likely represents anAplysia-biotransformed compound. This is the first clear reported observation of metabolite transfer between an alga of the phylum Phaeophyta and a sea hare.     

Isolation of two nitrogen-free toxins from tung kernels

Summary A procedure is described for isolating two nitrogen-free toxins from tung kernels and from press cake. Chick-feeding tests were used to determine which fraction was toxic at every separation. Both substances were highly toxic as 10-mg. doses killed 4-day old chicks. These substances were shown by chromatography on glass paper to be different and chromatography homogeneous, but also unstable. The elementary composition, hydroxyl content, saponification value, and specific rotation for the two toxins are given. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U, S. Department of Agriculture.     

Physiological and behavioral effects of coniferyl benzoate on avian reproduction

Various plant secondary metabolites related to cinnamic acid are of interest because of their repellency to birds and their occurrence in ecologically important food items. Coniferyl benzoate (CB), a phenylpropanoid ester that occurs in quaking aspen (Populus tremuloides) is of particular ecological interest because of its effect on ruffed grouse (Bonasa umbellus) feeding behavior and its possible influence on the population dynamics of this bird. During detoxification processes, CB and other analogous compounds are metabolized into by-products, such as ferulic acid (FA), that can cause anti-reproductive effects. We tested whether consumption of CB produces antire-productive effects similar to FA using male and female Japanese quail (Coturnix coturnix) as avian models for ruffed grouse. The parameters we investigated included: the production, morphology, and development of eggs; reproductive characteristics influenced by estrogen; serum prolactin levels; and male reproductive behavior. Dietary CB did not produce antireproductive effects similar to FA at intake levels that Japanese quail and ruffed grouse would freely consume. Consumption of CB by Japanese quail significantly reduced egg production and body mass but did not affect male reproductive performance. Coniferyl benzoate's effect on egg production may be explained by lower energy acquisition and retention rather than endocrine changes per se. Contrary to previous reports, it is unlikely that FA, or similar compounds act directly as estrogen mimics or antagonists. Although, CB did reduce egg production in quail, it is unlikely that it would affect egg production in wild ruffed grouse. Detoxification costs and the effects of CB on nutrient utilization may explain why ruffed grouse avoid high dietary levels of CB.     

Effect of eicosa-5,8,11,14-tetraynoic acid on fatty acid composition of selected organs in the rat

Eicosa-5,8,11,14-tetraynoic acid or arachidonic acid or no supplement (controls) was given orally to rats maintained on a fat free diet and the fatty acid composition of total lipids of several organs determined. No changes were noted in the total fatty acid concentrations of the organs examined in the various groups. A decrease in the amount of arachidonic acid, 22∶4ω6 and 22∶5ω6 (as percent of total fatty acids), and an increase in the amount of 20∶3ω6 and linoleate were observed in total lipids of several organs. In the group receiving the arachidonate supplement, there was less linoleate and 20∶3ω6 and more arachidonate than in the controls. Both eicosa-5,8,11,14-tetraynoic acid and arachidonate supplements resulted in a decrease in 20∶3ω9 in most organs studied. Generally, the most marked changes were seen in liver but, of the other organs examined (heart, kidney, testis, brain, and adrenals), only the adrenals failed to show any significant differences between the controls and each of the two supplemented groups. Although the experimental conditions preclude conclusive interpretation of the changes observed, it is suggested that eicosa-5,8,11,14-tetraynoic acid was effective in inhibiting the conversion of linoleate to arachidonate and the conversion of arachidonate to 22∶4 and 22∶5.     

Human interaction with policy flight simulators

Policy flight simulators are designed for the purpose of exploring alternative management policies at levels ranging from individual organizations to national strategy. This article focuses on how such simulators are developed and on the nature of how people interact with these simulators. These interactions almost always involve groups of people rather than individuals, often with different stakeholders in conflict about priorities and courses of action. The ways in which these interactions are framed and conducted are discussed, as well as the nature of typical results.     

Atmospheric pressure chemical ionization mass spectrometry for analysis of lipids

Atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) has proven to be a very valuable technique for analysis of lipids from a variety of classes. This instrumental method readily produces useful ions with gentle fragmentation from large neutral molecules such as triacylglycerols and carotenoids, which are often difficult to analyze using other techniques. Molecules that are easily ionized, such as phospholipids, produce molecular ions and diagnostically useful fragment ions that are complementary to those produced by methods such as electrospray ionization MS with collision-induced dissociation. The simplicity and versatility of APCI-MS make it an ideal tool for use in solving hitherto very difficult analytical problems.     

Paradox Lost: The Evolution of Strategies in Selten’s Chain Store Game

The classical game theoretic resolutions to Selten’s Chain Store game are unsatisfactory; they either alter the game to avoid the paradox or struggle to organize the existing experimental data. This paper applies co-evolutionary algorithms to the Chain Store game and demonstrates that the resulting system’s dynamics are neither intuitively paradoxical nor contradicted by the existing experimental data. Specifically, some parameterizations of evolutionary algorithms promote genetic drift. Such drift can lead the system to transition among the game’s various Nash Equilibria. This has implications for policy makers as well as for computational modelers.