Electrophoretic Treatment Research Articles

Corrosion behavior of riveted joints with electrophoretic treatment in neutral salt spray environment

AbstractThis study delves into the corrosion behavior of riveted joints with electrophoretic treatment in a neutral salt spray environment using tensile test and surface analysis. The results showed that the open‐circuit potentials of the dual‐phase steels (590DP and 780DP) exceeded those of the AlSi10MnMg‐T7 and JDA1b die‐casting aluminum alloys by 100 mV, and exceeded that of the AA6063‐T6 extruded aluminum alloy by 50 mV. AlSi10MnMg‐T7 and JDA1b die‐casting aluminum alloys were more susceptible to corrosion in contrast to the AA6063‐T6 extruded aluminum alloy. The corrosion mechanism of the steel/aluminum riveted joints was not only galvanic corrosion but also oxygen concentration polarization. Over the 720‐h corrosion period, the failure loads of the riveted joints were not reduced at all. On the contrary, they increased at least 17% for the two‐sheet self‐piercing riveting (SPR) joints, 6% for the three‐sheet SPR joints, and 4% for the flow drill screw joints.

Fabrication and characterization of titanium-dioxide nanotubes grown by using an electrophoretic-hydrothermal method

Titania (TiO2) nanotubes were grown by using a solution-based method that combined a hydrothermal process with an electrophoretic treatment. We prepared a Teflon autoclave for electrophoretic. hydrothermal synthesis and measured the surface morphology and the crystal structure of TiO2 by using transmission electron microscopy, X-ray diffraction, and field-emission scanning electron microscopy. The optical properties were investigated by using photoluminescence as well as transmittance and reflectance measurements. The synthesis technique is suitable for inexpensive mass production and for obtaining remarkable electrochemical properties such as those offered by highly-ordered nanotube arrays. In addition to producing a homogeneous and robust film on the surface of the substrate, particles and clusters can be aligned on the substrate surface with a desired direction by using an applied electric field.

Lactate dehydrogenase in the eider—An unusual pattern

1. 1. The lactate dehydrogenase of eiders ( Somateria mollissima) of both sexes, and of widely separated populations, were studied. 2. 2. Electrophoretic treatment at different pH values before and after reversible denaturation of the enzyme revealed only one enzyme, regardless from from which tissue the sample was taken. 3. 3. The physiological significance of this peculiar enzyme pattern is discussed.

Fractionation of plant material. III.—Two schemes for chemical fractionation of fresh leaves, having special applicability for isolation of the bulk protein

AbstractNearly all the protein of broad‐bean leaves other than cell‐wall protein was readily extracted into phenol‐acetic acid‐water mixtures, and further purified by free‐solution eletrophoresis therein, using the continuous apparatus of Hannig. Under these conditions RNA migrated cationically in association with the protein. Adding salt did not greatly improve the separation, but it reversed the relative cationic migration rates of phaeophytin a and protein. Liquid‐liquid partition between phenol and aqueous buffer phases gave good separation of the protein from RNA.Scheme I involved successive extraction of the leaves with 5% (w/v) aqueous trichloroacetic acid, ethanol and phenol‐acetic acid‐water; the bulk of the protein went into this last solvent mixture and did not require further electrophoretic treatment. In Scheme II, components of low molecular weight were washed out from the plasmolysed leaves with water. Extraction was then carried out with phenol‐acetic acid‐water, and this extract was further fractionated by electrophoresis. The non‐migrating fraction should be valuable starting material for studies of a variety of leaf constituents. The extraction residues are promising starting material for studies of the leaf polysaccharides and other cell‐wall components.The protein preparations contained little phosphorus or carbohydrate but were brown and had high C/N ratios and higher ultra‐violet absorption than corresponded to the aromatic amino acids present. This was decreased, but not abolished, by keeping the work under nitrogen. Model experiments showed good electrophoretic separation of protein from polyphenols and tannic acid under the same conditions. The extraneous aromatic material is therefore presumed to be bound covalently to the protein. Coupling of oxidatively polymerising quinones to side‐chains of amino acid residues, especially lysine, seems probable. The occurrence of such reactions in leaves has implications for the nutritive value of their proteins. Such products may also contribute directly to the ‘humic acid’ fraction of soil.