Energy-power conditions for drawing bimetal blanks

A procedure for determining the optimal geometry of a drawing tool for drawing a bimetal blank is proposed. The optimum cone angles of the drawing tool, which offers the minimum drawing stress and minimum energy consumption during the manufacture of bimetal articles, were found from the condition of minimum of the drawing stress.     

The FKBP5 Gene Affects Alcohol Drinking in Knockout Mice and Is Implicated in Alcohol Drinking in Humans

FKBP5 encodes FK506-binding protein 5, a glucocorticoid receptor (GR)-binding protein implicated in various psychiatric disorders and alcohol withdrawal severity. The purpose of this study is to characterize alcohol preference and related phenotypes in Fkbp5 knockout (KO) mice and to examine the role of FKBP5 in human alcohol consumption. The following experiments were performed to characterize Fkpb5 KO mice. (1) Fkbp5 KO and wild-type (WT) EtOH consumption was tested using a two-bottle choice paradigm; (2) The EtOH elimination rate was measured after intraperitoneal (IP) injection of 2.0 g/kg EtOH; (3) Blood alcohol concentration (BAC) was measured after 3 h limited access of alcohol; (4) Brain region expression of Fkbp5 was identified using LacZ staining; (5) Baseline corticosterone (CORT) was assessed. Additionally, two SNPs, rs1360780 (C/T) and rs3800373 (T/G), were selected to study the association of FKBP5 with alcohol consumption in humans. Participants were college students (n = 1162) from 21–26 years of age with Chinese, Korean or Caucasian ethnicity. The results, compared to WT mice, for KO mice exhibited an increase in alcohol consumption that was not due to differences in taste sensitivity or alcohol metabolism. Higher BAC was found in KO mice after 3 h of EtOH access. Fkbp5 was highly expressed in brain regions involved in the regulation of the stress response, such as the hippocampus, amygdala, dorsal raphe and locus coeruleus. Both genotypes exhibited similar basal levels of plasma corticosterone (CORT). Finally, single nucleotide polymorphisms (SNPs) in FKBP5 were found to be associated with alcohol drinking in humans. These results suggest that the association between FKBP5 and alcohol consumption is conserved in both mice and humans.     

High-entropy boride–carbide ceramics by sequential boro/carbothermal synthesis

A dual-phase high-entropy boride (HEB)/carbide (HEC) ceramic with a fine grain size was synthesized by a sequential boro/carbothermal process. In the first step, an Hf–Nb–Ta–Ti–Zr-containing carbide was synthesized by a carbothermal reduction of oxides followed by the reaction of the carbide with B₄C and ZrH₂ to convert part of the carbide to boride. The resulting composition was ∼29 vol% HEB with an average grain size of ∼1.1 μm. Solid solution formation occurred at the densification temperature of 1900°C resulting in a relative density higher than 99%. The Vickers hardness was 26.5 ± 1.4 GPa. This is the first report of synthesizing dual-phase boride–carbide high-entropy ceramics from carbothermally synthesized, HEC powders.     

Thermal Expansion of Alkaline‐Doped Lanthanum Ferrite Near the Néel Temperature

The thermal expansion and magnetic behaviors of divalent, alkaline‐doped lanthanum ferrites (La_0.9M_0.1FeO₃, M=Ca, Sr, Ba) were assessed using a combination of dilatometry, magnetometry, time‐of‐flight neutron diffraction, and high‐temperature X‐ray diffraction. Néel temperatures were determined through vibrating sample magnetometry and correlated well with changes in thermal expansion behavior observed during both dilatometry and X‐ray diffraction. The Néel temperatures observed for pure, Ca‐doped, Sr‐doped, and Ba‐doped lanthanum ferrites were 471°C, 351°C, 465°C, and 466°C, respectively. The effect of divalent substitutions on the magnetic behavior are attributed to charge compensation mechanisms and structural changes in the material.     

Influence of Macromolecular Brushes with Polyimide Backbones and Poly(methyl methacrylate) Side Chains on Structure,Physical, and Transport Properties of Polyphthalamide

Composite films based on polyamide (poly(m-phenylene-iso-phthalamide)) (PA) and a brush-like polymer with polyimide (PI) backbone and side poly(methyl methacrylate) chains (PI-PMMA) were prepared by mixing individual solutions of PA and PI-PMMA and subsequent film casting. Macromolecular brushes with the same backbone length and density of side chains but with various lengths of side PMMA chains were synthesized via activator generated by electron transfer atom transfer radical polymerization. Interactions between PA and PI-PMMA, as well as distribution of PI-PMMA filler inside the PA matrix, were studied by viscometry, dynamic light scattering, differential scanning calorimetry, scanning electron microscopy, and IR spectroscopy. The mechanical properties of polymer samples were also investigated. Microphase separation was revealed in PA/PI-PMMA films. The length of side chains influences interactions between PA and PI-PMMA. At the same time, the degree of reduction in the rigidity parameters and in the elasticity parameter depends on the side chain length. Diffusion membranes were prepared on the basis of compositions with the best mechanical properties; these membranes proved to be highly efficient in pervaporation of methanol–hexane mixture. It was established that the fluxes and separation factors of the studied membranes are several times higher as compared to the corresponding characteristics of known commercial membranes. POLYM. ENG. SCI., 60:481–490, 2020. © 2019 Society of Plastics Engineers     

Penetration of Sodium Tripolyphosphate into Fresh and Prefrozen Peeled and Deveined Shrimp

The distribution of sodium tripolyphosphate (STP) in peeled and deveined shrimp tails after treatment was investigated using P³² labeled STP. Fresh and frozen brown (Penaeus aztecus) and fresh and frozen white (Penaeus setiferus) shrimp were used in the study. Shrimp were treated in solutions of either 0.5%, 1%, 5%, or 10% STP that had been prepared using P³² labeled STP diluted with “cold” STP. The duration of treatment was either 20 sec, 1 min, 5 min, or 20 min. When shrimp were treated in 0.5% and 1% STP solutions, a phosphate concentration gradient was evident in the shrimp muscle. After such treatments, STP was shown to accumulate on the surface of the muscle preventing further STP uptake. At higher STP concentrations (5% and 10% solutions) prolonged time treatments overcame the concentration gradient as STP became equally distributed through the shrimp muscle (4.8 mm). No difference in the STP penetration mechanism between fresh and prefrozen treated shrimo was evident.     

Influence of small additives of rare-earth elements on the structure of fluorophosphate glasses

The physicochemical properties and Raman spectra of glasses of the composition 40Ba(PO₃)₂ · 60MgCaSrBaAl₂F₁₄ doped with europium and terbium have been investigated. The results of the performed investigations have been compared with the data of the analysis of the recorded EPR spectra of irradiated glasses of the same compositions in terms of the model of the effective capture volume and with the luminescence data available in the literature. The concentration ranges of terbium and europium ions (0.05–0.10) mol % or (0.7–1.3) × 10¹⁹ ions/cm³, in which these ions retain the oxygen environment according to the analysis of the studies carried out by different methods, are in satisfactory agreement. The dependence of the local environment of rare-earth ions in fluorophosphate glasses on their concentration has been established.     

Preparation and Characterization of Alkoxy-Derived SrZrO3 and SrTiO3

High-purity strontium, zirconium, and titanium alkoxides were synthesized and characterized as precursors for complex oxides. Simultaneous hydrolytic decomposition either of strontium and zirconium alkoxides or of strontium and titanium alkoxides was used to obtain nearly stoichiometric, ideally mixed SrZrO₃ or SrTiO₃ powders of high surface activity. As-prepared helium-dried SrTiO₃ is crystalline before calcination. An ultraviolet radiation technique demonstrates the nucleation and growth of SrZrO₃ crystallites in the calcination temperature range to 350°C. The experimental results are supported by ir, TGA, and X-ray diffraction data. The high degree of control over purity, mixing uniformity, and crystallite size demonstrates the value of the alkoxide precursor approach for the solution of reproducibility problems encountered in the synthesis of electrical-quality ceramics.