Developments in the continuous galvanizing of steel

The performance history of galvanized steels, particularly in the automotive industry, has heightened demand for both hot-dip galvanized and electrogalvanized products. Such marketability has led to the commissioning of several new galvanizing lines in recent years. Still, for this timehonored coating process to remain competitive, researchers are investigating methods to improve surface appearance, coating uniformity, corrosion resistance and cost effectiveness.     

ASTUDY OF VALENCE OF YTTRIUM IN Y_2O_3 Mo CATHODE

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Computer simulation of the corrosion inhibition of copper in acidic solution by alkyl esters of 5-carboxybenzotriazole

A series of alkyl esters (methyl, butyl, hexyl, and octyl) synthesised from a mixture of 4- and 5-carboxybenzotriazole (4-CBTAH and 5-CBTAH) inhibited copper corrosion in aerated solution (pH∼0). Inhibition efficiency (IE%) of the protonated esters (CBTAH₂⁺-R) increased with hydrocarbon chain length and this is attributed to chemisorption (through azole ring N) and increased physical adsorption as more methyl groups are introduced. A modelling package employing molecular mechanics and molecular dynamics has been used to simulate the docking of a single protonated species (5-CBTAH₂⁺-R) onto a clean copper (1 1 0) surface. A decrease in potential energy was associated with the flattening of the ester ring system onto the surface and further decreases in energy were associated with the extension of the aliphatic chain onto the surface. The crude binding energy (E_bind) of each ester with the surface was estimated and this energy also increased regularly with carbon chain length. The study suggests that molecular modelling and calculation of E_bind of a single molecule on a specified metallic surface can be used to predict the inhibition performance of compounds whose structures change in a regular way.     

Weldability and microstructural variations in weldments of Ti-5Ta-1.8Nb alloy

The successful replacement of the present generation of corrosion-resistant materials (nitric acid-grade stainless steel and Ti) by Ti-5Ta-1.8Nb, which has better corrosion resistance, depends on its weldability characteristics. This article presents the results of a study on the fabrication, qualification, and microstructural characterization of the welds. Welding was carried out using the direct current electrode negative (DCEN) polarity tungsten inert gas (TIG) (manual) welding method with high-purity Ar shielding. Testing was carried out as per the ASME standard (section IX, welding and brazing). Qualification tests found that the weldment met the required properties. The weldment showed heterogeneous microstructures, which are rationalized based on differences in phase transformation mechanisms that are dictated by the thermal cycles experienced by various microscopic regions. The results, described in this article, confirm that the weldability of the developmental Ti-Ta-Nb alloy is excellent. A preliminary evaluation of the corrosion behavior of the welds showed rates comparable to that of the base metal, establishing that this alloy could be considered as an alternative material for use in highly corrosive environments.     

Inhibitors of Mitochondrial Human Carbonic Anhydrases VA and VB as a Therapeutic Strategy against Paclitaxel-Induced Neuropathic Pain in Mice

Neuropathy development is a major dose-limiting side effect of anticancer treatments that significantly reduces patient’s quality of life. The inadequate pharmacological approaches for neuropathic pain management warrant the identification of novel therapeutic targets. Mitochondrial dysfunctions that lead to reactive oxygen species (ROS) increase, cytosolic Ca²⁺ imbalance, and lactate acidosis are implicated in neuropathic pain pathogenesis. It has been observed that in these deregulations, a pivotal role is played by the mitochondrial carbonic anhydrases (CA) VA and VB isoforms. Hence, preclinical studies should be conducted to assess the efficacy of two novel selenides bearing benzenesulfonamide moieties, named 5b and 5d, and able to inhibit CA VA and VB against paclitaxel-induced neurotoxicity in mice. Acute treatment with 5b and 5d (30–100 mg/kg, per os – p.o.) determined a dose-dependent and long-lasting anti-hyperalgesic effect in the Cold plate test. Further, repeated daily treatment for 15 days with 100 mg/kg of both compounds (starting the first day of paclitaxel injection) significantly prevented neuropathic pain development without the onset of tolerance to the anti-hyperalgesic effect. In both experiments, acetazolamide (AAZ, 100 mg/kg, p.o.) used as the reference drug was partially active. Moreover, ex vivo analysis demonstrated the efficacy of 5b and 5d repeated treatments in reducing the maladaptive plasticity that occurs to glia cells in the lumbar portion of the spinal cord and in improving mitochondrial functions in the brain and spinal cord that were strongly impaired by paclitaxel-repeated treatment. In this regard, 5b and 5d ameliorated the metabolic activity, as observed by the increase in citrate synthase activity, and preserved an optimal mitochondrial membrane potential (ΔΨ) value, which appeared depolarized in brains from paclitaxel-treated animals. In conclusion, 5b and 5d have therapeutic and protective effects against paclitaxel-induced neuropathy without tolerance development. Moreover, 5b and 5d reduced glial cell activation and mitochondrial dysfunction in the central nervous system, being a promising candidate for the management of neuropathic pain and neurotoxicity evoked by chemotherapeutic drugs.     

The Properties of Synthetic Amylopectin with Long External-Chains

Samples of synthetic amylopectins with long external chain-lengths have been prepared from degraded, waxy maize amylopectin and glucose-1-phosphate by the action of potato phosphorylase. Samples having external chain-lengths determined by enzymic assay of 23.4, 29.9, 46.5, and 109.5 glucose units (original sample = 13.7 glucose units) were prepared. The iodine-staining properties of these materials have been investigated, and a relation between λ_max and average chain-length evaluated. A theoretical relation between chain-length and β-amylolysis limit has been proposed. The iodine-binding capacity of the samples has been studied in detail by potentiometric titration at 1.5 °C and 20 °C. Unambiguous conclusions regarding the observed iodine binding capacity and the length of external chain have been made for the first time. The properties of the synthetic products are discussed.     

Pflanzenschutzmittelrückstände – ihre Problematik und analytische Erfassung

Pesticide Residues – Problems and Analytical Detection. With regard to storage protection pesticides are used in large quantities. Since many insecticides at the same time represent strong poisons the application calls for considerable care. The toxicological influence of the effective substances used for grain storage preventive purposes on warm blooded animals is pointed out. Because in foreign countries partly other pesticides are applied the effective substances permitted in the Federal Republic of Germany are compared with those used abroad. The tolerances in the Federal Republic of Germany and those of foreign countries are compared. Because the permissible residues are very small, the analytical detection is rather difficult and time consuming. Some analytical procedures as well as problems of sampling and zero tolerances are described. In connection with the analytical determination of grain and starches, the decrease of pesticide residues in the course of technological processes has been studied. The results are discussed. Finally an outlook to new methods of pest control is presented.