Improvement of antioxidation and antiwear properties of polyalphaolefin oils

Polyalphaolefin-based lubricating oils were tested on a four-ball tester, and in a stability test, with antiwear and antioxidant additives of different types, along with other (petroleum and alkylbenzene) base oils and additives. Antioxidant additives for PAOs essentially influence their thermo-oxidation stability. It was found that binary inhibitors increased thermo-oxidation stability effectively. In the antiwear tests, the addition of additives to PAOs sharply decreased wear scar diameters. A significant difference was observed in the action of small concentrations of antiwear additives as between PAO, alkylbenzene and mineral oils. Explanations of this behaviour are put forward.     

Some Grain Properties of IR36-based Starch Mutants

Some grain properties of 20 starch mutants that were transferred from mutants of Japanese rices to IR36 (by two backcrosses to IR36) were studied. All had higher apparent amylose content (AC) and gelatinization temperature (GT) than the parent mutants, except the dull mutants, and the 82GF sugary mutant which had no amylose. All had lighter and lower density brown rices than IR36. Sugary 82GF und EM5 had high free sugars, and sugary and EM20 shrunken-1 had high fat content. Phytoglycogen content of brown rice was 34% for 82GF and 7% for EM5 sugary mutants. Amylose extender mutants had higher lysine in brown rice protein than IR36 parent. Alkali spreading value did not accurately estimate GT of these starch mutants. Milled rice of the two high amylose extender mutants 2064 and EM16 had lower Amylograph peak viscosity but higher cooked rice Instron hardness than IR36 milled rice.     

Study of a Nanostructured Anatase Coating on the Rutile Surface

Russian Journal of Non-Ferrous Metals - Nanosized titanium dioxide allows solving complex engineering problems. One such a problem is the development of materials and coatings that reduce the...     

Production of Composite Titanium Diboride Powder Materials and Coatings

Powder Metallurgy and Metal Ceramics - The structure and properties of detonation coatings and composite powder materials of various composition were studied. The detonation spraying of coatings...     

Use of Tin-Bismuth (Sn–Bi) Eutectic Alloy in Contact with Austenitic Class Steel for Hydraulic Seals

Metallurgist - Quantitative results are presented for a study of the interaction of tin-bismuth eutectic alloy (used as a solder) as the working body of a hydraulic seal in contact with austenitic...     

Development of the Metal Temperature Prediction Model for Steel-pouring and Tundish Ladles Used at the Casting and Rolling Complex

Metallurgist - A model has been developed for predicting the metal temperature in the specified superheat range above the liquidus temperature inside the tundish of a continuous casting machine...     

Broad Spectrum Anti-Bacterial Activity and Non-Selective Toxicity of Gum Arabic Silver Nanoparticles

Silver nanoparticles (AgNPs) are the most commercialized nanomaterials and presumed to be biocompatible based on the biological effects of the bulk material. However, their physico-chemical properties differ significantly to the bulk materials and are associated with unique biological properties. The study investigated the antimicrobial and cytotoxicity effects of AgNPs synthesized using gum arabic (GA), sodium borohydride (NaBH₄), and their combination as reducing agents. The AgNPs were characterized using ultraviolet-visible spectrophotometry (UV-Vis), dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The anti-bacterial activity was assessed using agar well diffusion and microdilution assays, and the cytotoxicity effects on Caco-2, HT-29 and KMST-6 cells using MTT assay. The GA-synthesized AgNPs (GA-AgNPs) demonstrated higher bactericidal activity against all bacteria, and non-selective cytotoxicity towards normal and cancer cells. AgNPs reduced by NaBH₄ (C-AgNPs) and the combination of GA and NaBH₄ (GAC-AgNPs) had insignificant anti-bacterial activity and cytotoxicity at ≥50 µg/mL. The study showed that despite the notion that AgNPs are safe and biocompatible, their toxicity cannot be overruled and that their toxicity can be channeled by using biocompatible polymers, thereby providing a therapeutic window at concentrations that are least harmful to mammalian cells but toxic to bacteria.     

Toward Xeno-Free Differentiation of Human Induced Pluripotent Stem Cell-Derived Small Intestinal Epithelial Cells

The small intestinal epithelium has an important role in nutrition, but also in drug absorption and metabolism. There are a few two-dimensional (2D) patient-derived induced pluripotent stem cell (iPSC)-based intestinal models enabling easy evaluation of transcellular transport. It is known that animal-derived components induce variation in the experimental outcomes. Therefore, we aimed to refine the differentiation protocol by using animal-free components. More specifically, we compared maturation of 2D-cultured iPCSs toward small intestinal epithelial cells when cultured either with or without serum, and either on Geltrex or on animal-free, recombinant laminin-based substrata. Differentiation status was characterized by qPCR, immunofluorescence imaging, and functionality assays. Our data suggest that differentiation toward definitive endoderm is more efficient without serum. Both collagen- and recombinant laminin-based coating supported differentiation of definitive endoderm, posterior definitive endoderm, and small intestinal epithelial cells from iPS-cells equally well. Small intestinal epithelial cells differentiated on recombinant laminin exhibited slightly more enterocyte specific cellular functionality than cells differentiated on Geltrex. Our data suggest that functional small intestinal epithelial cells can be generated from iPSCs in serum-free method on xeno-free substrata. This method is easily converted to an entirely xeno-free method.     

Peculiarities of Corrosion of a Zinc Coating in Neutral Media in the Presence of Inhibitors Based on Benzotriazole,Cyclohexylamine, and Morpholine

Russian Journal of Non-Ferrous Metals - The influence of domestic nitrogen-containing corrosion inhibitors of the VNKh-L type on corrosion regularities of a zinc coating on steel in neutral media...     

The Functional Properties Acquired by Antifriction Composites Produced from Silumin Grinding Waste

Powder Metallurgy and Metal Ceramics - The paper analyzes how the antifriction composites produced from AK12MMgN silumin grinding waste with MoS2 solid lubricant additions acquire their structure...