Sodium Mass Transfer: II, Screening Test Data and Analysis

In 1959 the U. S. Atomic Energy Commission contracted with the General Electric Company to carry out a Sodium Mass Transfer investigation with the objective of evaluating three prospective steel construction materials for utilization in liquid sodium-cooled reactor systems operated in the temperature range of 600 to 1300 F. Six liquid sodium test loops were designed and built to implement the study of the three selected materials: AISI 316 stainless steel (316SS); 2 1/4 percent Chromium- 1 percent Molybdenum steel (2 1/4 Cr-1Mo), and 5 percent Chromium - 1/2 percent Molybdenum- 1/2 percent Titanium steel (5Cr-1/2Mo-Ti). This document reports and interprets extensive observations of the metallurgical effects noted after exposure of the materials to liquid sodium. This exposure was made under dynamic conditions in test runs of up to 3000 hours from the initial startup through December 1961

Superlattices: Progress and prospects

The current status of HgTe–CdTe superlattices is reviewed. The properties predicted for the superlattices have been studied qualitatively in the cases where both theory and experiment exist. In particular, it has been found by both infrared absorption and photoluminescence that band gaps of the superlattices are substantially less than those of the alloy with the same average composition. Theoretical studies have concentrated on the factors (strain, band offsets, interdiffusion) that could result in substantial deviation of the properties of the superlattices from those predicted by the original simple theories. Some of the areas requiring further development are reviewed and discussed

Infrared absorption measurement and analysis of HgTe–CdTe superlattices

The near-band-gap optical properties of superlattice are essential in determining the usefulness of these structures for application in infrared systems. In this paper we report on studies of a HgTe–CdTe superlattice. The optical characterization of the superlattice in the infrared was carried out by measuring its photoluminescence, transmission, and photoconductivity spectra. Results of these measurements as functions of temperature are presented, as are the theoretically calculated absorption spectra. We obtained good agreement between different measurement techniques and the theoretical model for the optical absorption and band gap

Rhodococcus opacus B4: a promising bacterium for production of biofuels and biobased chemicals

Bacterial lipids have relevant applications in the production of renewable fuels and biobased oleochemicals. The genus Rhodococcus is one of the most relevant lipid producers due to its capability to accumulate those compounds, mainly triacylglycerols (TAG), when cultivated on different defined substrates, namely sugars, organic acids and hydrocarbons but also on complex carbon sources present in industrial wastes. In this work, the production of storage lipids by Rhodococcus opacus B4 using glucose, acetate and hexadecane is reported for the first time and its productivity compared with Rhodococcus opacus PD630, the best TAG producer bacterium reported. Both strains accumulated mainly TAG from all carbon sources, being influenced by the carbon source itself and by the duration of the accumulation period. R. opacus B4 produced 0.09 and 0.14 g L1 at 24 and 72 h, with hexadecane as carbon source, which was 2 and 3.3 fold higher than the volumetric production obtained by R. opacus PD630. Both strains presented similar fatty acids (FA) profiles in intact cells while in TAG produced fraction, R. opacus B4 revealed a higher variability in fatty acid composition than R. opacus PD630, when both strains were cultivated on hexadecane. The obtained results open new perspectives for the use of R. opacus B4 to produce TAG, in particular using oily (alkane-contaminated) waste and wastewater as cheap raw-materials. Combining TAG production with hydrocarbons degradation is a promising strategy to achieve environmental remediation while producing added value compounds.This work was financially supported by the Portuguese Science Foundation (FCT) and European Social Fund (ESF, POPH-QREN) through the Grant given to A.R. Castro (SFRH/BD/64500/2009), the FCT Strategic Project of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)

Extended 2D myotube culture recapitulates postnatal fibre type plasticity

Background: The traditional problems of performing skeletal muscle cell cultures derived from mammalian or avian species are limited myotube differentiation, and transient myotube persistence which greatly restricts the ability of myotubes to undergo phenotypic maturation. We report here on a major technical breakthrough in the establishment of a simple and effective method of extended porcine myotube cultures (beyond 50 days) in two-dimension (2D) that recapitulates key features of postnatal fibre types. Results: Primary porcine muscle satellite cells (myoblasts) were isolated from the longissimus dorsi of 4 to 6 weeks old pigs for 2D cultures to optimise myotube formation, improve surface adherence and characterise myotube maturation. Over 95 % of isolated cells were myoblasts as evidenced by the expression of Pax3 and Pax7. Our relatively simple approach, based on modifications of existing surface coating reagents (Maxgel), and of proliferation and differentiation (Ultroser G) media, typically achieved by 5 days of differentiation fusion index of around 80 % manifested in an abundance of discrete myosin heavy chain (MyHC) slow and fast myotubes. There was little deterioration in myotube viability over 50 days, and the efficiency of myotube formation was maintained over seven myoblast passages. Regular spontaneous contractions of myotubes were frequently observed throughout culture. Myotubes in extended cultures were able to undergo phenotypic adaptation in response to different culture media, including the adoption of a dominant postnatal phenotype of fast-glycolytic MyHC 2x and 2b expression by about day 20 of differentiation. Furthermore, fast-glycolytic myotubes coincided with enhanced expression of the putative porcine long intergenic non-coding RNA (linc-MYH), which has recently been shown to be a key coordinator of MyHC 2b expression in vivo. Conclusions: Our revised culture protocol allows the efficient differentiation and fusion of porcine myoblasts into myotubes and their prolonged adherence to the culture surface. Furthermore, we are able to recapitulate in 2D the maturation process of myotubes to resemble postnatal fibre types which represent a major technical advance in opening access to the in vitro study of coordinated postnatal muscle gene expression

Two tools for integrating sonifications into calculus instruction

Presented at the 12th International Conference on Auditory Display (ICAD), London, UK, June 20-23, 2006.Two sonification tools are presented for use in calculus instruction. The first is a web-based tool for teaching students to interpret sonifications. The other is a spreadsheet-based tool that uses sonification to support and reinforce graphical and numeric representations of functions. We also illustrate how the tools could be used, and present data on the usability of the tools and the ability of students to interpret our sonifications