Volumetric out-of-furnace heat treatment of 3600-M3 decomposers

Specifications require that all the welds in 12-m-diam. decomposers with a capacity of 3600 m³ be subjected to high-temperature tempering before going into service in order to alleviate the stresses from the welding operation. Specialists at the organizations VNIIPTkhimnefteapparatury and VNIImontazhspetsstroi have proposed out-of-furnace volumetric (complete) of the assembled decomposer with the use of special heaters. The use of this heating method has shortened assembly operations while providing the welds with a highquality heat treatment and reducing the stresses overall (including welding stresses, stresses from assembly of the decomposer, etc.) The technology ensures uniform heating of the housing of the decomposer and provides for close control over the process. The experience gained in heat-treating decomposers can also be used in the construction of other containers that come into contact with corrosive media. __________ Translated from Metallurg, No. 3, pp. 61–64, March, 2006.     

hTERT-Driven Immortalization of RDEB Fibroblast and Keratinocyte Cell Lines Followed by Cre-Mediated Transgene Elimination

The recessive form of dystrophic epidermolysis bullosa (RDEB) is a crippling disease caused by impairments in the junctions of the dermis and the basement membrane of the epidermis. Using ectopic expression of hTERT/hTERT + BMI-1 in primary cells, we developed expansible cultures of RDEB fibroblasts and keratinocytes. We showed that they display the properties of their founders, including morphology, contraction ability and expression of the respective specific markers including reduced secretion of type VII collagen (C7). The immortalized keratinocytes retained normal stratification in 3D skin equivalents. The comparison of secreted protein patterns from immortalized RDEB and healthy keratinocytes revealed the differences in the contents of the extracellular matrix that were earlier observed specifically for RDEB. We demonstrated the possibility to reverse the genotype of immortalized cells to the state closer to the progenitors by the Cre-dependent hTERT switch off. Increased β-galactosidase activity and reduced proliferation of fibroblasts were shown after splitting out of transgenes. We anticipate our cell lines to be tractable models for studying RDEB from the level of single-cell changes to the evaluation of 3D skin equivalents. Our approach permits the creation of standardized and expandable models of RDEB that can be compared with the models based on primary cell cultures.     

Eco‐friendly synthesis of silver nanoparticles and its larvicidal property against fourth instar larvae of Aedes aegypti

In this study, larvicidal activity of silver nanoparticles (AgNPs) synthesised using apple extract against fourth instar larvae of Aedes aegypti was determined. As a result, the AgNPs showed moderate larvicidal effects against Ae. aegypti larvae (LC₅₀  = 15.76 ppm and LC₉₀  = 27.7 ppm). In addition, comparison of larvicidal activity performance of AgNPs at high concentration prepared using two different methods showed that Ae. aegypti larvae was fully eliminated within the duration of 2.5 h. From X‐ray diffraction, the AgNP crystallites were found to exhibit face centred cubic structure. The average size of these AgNPs as estimated by particle size distribution was in the range of 50–120 nm. The absorption maxima of the synthesised Ag showed characteristic Ag surface plasmon resonance peak. This green synthesis provides an economic, eco‐friendly and clean synthesis route to Ag.Inspec keywords: silver, nanofabrication, X‐ray diffraction, zoology, particle size, nanoparticles, biomedical materials, nanomedicineOther keywords: time 2.5 h, size 50 nm to 120 nm, silver nanoparticle, larvicidal property, instar larvae, Aedes aegypti, larvicidal effect, larvicidal activity performance, X‐ray diffraction, nanoparticle particle size distribution, absorption maxima, silver surface plasmon resonance peak     

Plugging behavior of gellan in porous saline media

In this article, the hydrodynamic behavior of dilute aqueous solutions of a natural polysaccharide—gellan in the porous media under the modeled oilfield conditions is described. The hydrodynamic properties of gellan and poly(acrylamide) solutions in saline porous media are compared. The influence of inorganic salts NaCl, KCl, CaCl₂, MgCl₂, and BaСl₂ on sol–gel and gel–sol transitions of dilute gellan solutions was evaluated. The mechanism of sol–gel transition in the presence of individual alkaline and alkaline‐earth metal salts is described on the basis of literature data. The viscometric measurements revealed that the effectiveness of salts to enhance gelation of gellan changes in the following order: BaСl₂ > CaCl₂ ≈ MgCl₂ > KCl > NaCl. The sol–gel and gel–sol phase transitions of gellan solution were also observed upon addition of oil field water containing 73 g L^?1 of alkaline and alkaline earth metal ions. During the injection of gellan solutions into the porous media saturated by saline water an oscillation of the injection pressure was observed. Such behavior of gellan is explained by either the sol‐to‐gel and the gel‐to‐sol transitions of the polymer taking place in saline water or the step‐by‐step plugging of high permeable channels until all high permeable channels of sand packs are plugged due to gellan invasion. The application of brine‐initiated gelation of gellan for water shutoff operations (WSO) in field conditions was demonstrated. Higher technological effectiveness of gellan injection in comparison with existing gelation systems was shown. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41256.     

High cyclic fatigue performance of Al–Cu–Mg–Ag alloy under T6 and T840 conditions

High cyclic fatigue (HCF) behavior of an AA2139 alloy belonging to Al–Cu–Mg–Ag system in T6 and T840 conditions was examined. The T840 treatment involving cold rolling with a 40% reduction prior to peak ageing provides an increase in tensile strength compared with the T6 condition. However, fatigue lifetime for two material conditions was nearly the same since there is weak effect of thermomechanical processing on micro-mechanisms of crack initiation and growth.     

Corrosion damage in welded joints in containers

The design of ultrasonic butt welded joints in rigid plastics with additional compressive force is investigated. Two methods of introducing the energy of ultrasonic oscillations in the immediate vicinity of the welding zone with the tangential introduction of the oscillations and the relative displacement of the welded elements in the joint plane and welding with two-sided tangential introduction of the oscillations are discussed.     

Increasing the rated capacity of power units installed at Russian nuclear power stations equipped with VVER-1000 reactors

Safe operation of the Balakovo nuclear power station’s Unit 2 built around a VVER-1000 reactor at a thermal power output of 3120 MW with meeting of the safety criteria and compliance with the requirements of existing regulatory documents is substantiated. Results from measurements of process parameters at a power output equal to 104% of its nominal value are presented.