Some studies on the behavior of W-RE thermocouple materials at high temperatures

Bare 0.25 mm diameter W-Re alloy thermoelements (W, W-3% Re, W-5% Re and W-25%) and BeO-insulated W-3% Re and W-25% Re thermoelements were examined for metallurgical, chemical and thermal emf changes after testing for periods up to 1000 hours at temperatures principally in the range 2000 to 2400 K. Environments for the tests consisted of high purity argon, hydrogen, helium or nitrogen gases. Commercially obtained bare-wire thermoelements typically exhibited a shift in their emf-temperature relationship upon initial exposure. The shift was completed by thermally aging the W-3% Re thermoelement for 1 hour and the W-25% Re thermoelement for 2 minutes at 2400 K in argon or hydrogen. Aged thermoelements experienced no appreciable drift with subsequent exposure at 2400 K in the gaseous environments. The chemically doped W3% Re thermoelement retained a small-grained structure for exposure in excess of 50 hours at 2400 K. BeO-insulated thermoelement assemblies showed varied behavior that depended upon the method of exposure. However, when the assemblies were heated in a furnace, no serious material incompatibility problems were found if the materials were given prior thermal treatments. Thermocouples, assembled from aged W-3% Re and W-25% Re thermoelements and degassed sintered BeO insulators, exhibited a drift of only 2 to 3 K during exposure in argon at 2070 K for 1029 hours

An investigation of W-3% Re and W-25% Re thermoelements in vacuum, argon and hydrogen Final report

High vacuum, argon, and hydrogen effects on bare wire rhenium thermoelements at high temperature

High reliability sheathed, beryllia insulated, tungsten-rhenium alloy thermocouple assemblies; their fabrication and EMF stability

Tantalum sheathed, BeO insulated, W-3% Re/W-25% Re thermocouple assemblies were fabricated and their emf drift determined during 2059 hours of exposure at 2073 K in a gaseous helium environment. The sheathed thermocouple assemblies were constructed from aged thermoelements, specially heat-treated BeO insulators, and specially cleaned and etched tantalum sheaths. Their thermal emf drifts ranged from the equivalent of only -0.3 to -0.8 K drift per 1000 hours of exposure at 2073 K. No evidence of any gross chemical attack or degradation of the component materials was found. The emf drift and material behavior of some unsheathed, BeO insulated, W-3% Re/W-25% Re thermocouples at 2250 and 2400 K were also determined. Unsheathed thermocouples tested in an argon environment at 2250 K for 1100 hours and at 2400 K for 307 hours exhibited changes in thermal emf that typically ranged from the equivalent of a few degrees K to as much as +11 K. Post-test examinations of these thermocouples revealed some undesirable material degradation and interaction which included erosion of the BeO insulators and contamination of the thermoelements by tantalum from the tantalum blackbody enclosure in which the thermocouples were contained

Efcacy of sodium bicarbonate ingestion strategies for protecting blinding

Sodium bicarbonate (NaHCO3) is a widely researched ergogenic aid, but the optimal blinding strategy during randomised placebo-controlled trials is unknown. In this multi-study project, we aimed to determine the most efficacious ingestion strategy for blinding NaHCO3 research. During study one, 16 physically active adults tasted 0.3 g·kg-1 body mass NaHCO3 or 0.03 g·kg-1 body mass sodium chloride placebo treatments given in different flavour (orange, blackcurrant) and temperature (chilled, room temperature) solutions. They were required to guess which treatment they had received. During study two, 12 recreational athletes performed time-to-exhaustion (TTE) cycling trials (familiarisation, four experimental). Using a randomised, double-blind design, participants consumed 0.3 g·kg-1 body mass NaHCO3 or a placebo in 5 mL·kg-1 body mass chilled orange squash/water solutions or capsules and indicated what they believed they had received immediately after consumption, pre-TTE and post-TTE. In study one, NaHCO3 prepared in chilled orange squash resulted in the most unsure ratings (44%). In study two, NaHCO3 administered in capsules resulted in more unsure ratings (% here) than NaHCO3 (% here) given in solution, with differences in treatment assignment after consumption, epre-TTE, and post-TTE (all p<0.05). Administering NaHCO3 in capsules was the most efficacious blinding strategy which provides important implications for researchers conducting randomised placebo-controlled trials

Draft Genome Sequence of Frankia sp. Strain CcI6, a Salt-Tolerant Nitrogen-Fixing Actinobacterium Isolated from the Root Nodule of Casuarina cunninghamiana

Members of the actinomycete genus Frankia form a nitrogen-fixing symbiosis with 8 different families of actinorhizal plants. We report a 5.57-Mbp draft genome sequence for Frankia sp. strain CcI6, a salt-tolerant nitrogen-fixing actinobacterium isolated from root nodules of Casurina cunninghamiana grown in Egyptian soils

Long-distance Spore Transport: Vertical Sections of Spore Clouds over the Sea

RESP-566

Permanent Draft Genome Sequences for Two Variants of Frankia sp. Strain CpI1, the First Frankia Strain Isolated from Root Nodules of Comptonia peregrina

Frankia stains CpI1-S and CpI1-P are members of Frankia lineage Ia that are able to reinfect plants of the Betulaceae and Myricaceae families. Here, we report two 7.6-Mbp draft genome sequences with 6,396 and 6,373 candidate protein-coding genes for CpI1-S and CpI1-P, respectively

Sodium bicarbonate and time-to-exhaustion cycling performance: a retrospective analysis exploring the mediating role of expectancy

Background: A body of evidence has shown that ingesting 0.3 g·kg-1 body mass sodium bicarbonate (NaHCO3) can improve time-to-exhaustion (TTE) cycling performance, but the influence of psychophysiological mechanisms on ergogenic effects is not yet understood. Objective: This study retrospectively examined whether changes in TTE cycling performance are mediated by positive expectations of receiving NaHCO3 and/or decline in blood bicarbonate. Methods: In a randomised, crossover, counterbalanced, double-blind, placebo-controlled design, 12 recreationally trained cyclists (maximal oxygen consumption, 54.4 ± 5.7 mL·kg·min-1) performed four TTE cycling tests 90 min after consuming: i) 0.3 g·kg-1 body mass NaHCO3 in 5 mL·kg-1 body mass solution, ii) 0.03 g·kg-1 body mass sodium chloride in solution (placebo), iii) 0.3 g·kg-1 body mass NaHCO3 in capsules and iv) cornflour in capsules (placebo). Prior to exercise, participants rated on 1 – 5 Likert type scales how much they expected the treatment they believe had been given would improve performance. Capillary blood samples were measured for acid-base balance at baseline, pre-exercise and post-exercise. Results: Administering NaHCO3 in solution and capsules improved TTE compared with their respective placebos (solution: 27.0 ± 21.9 s, p = 0.001; capsules: 23.0 ± 28.1 s, p = 0.016). Compared to capsules, NaHCO3 administered via solution resulted in a higher expectancy about the benefits on TTE cycling performance (Median: 3.5 vs. 2.5, Z = 2.135, p = 0.033). Decline in blood bicarbonate during exercise was higher for NaHCO3 given in solution compared to capsules (2.7 ± 2.1 mmol·L-1, p = 0.001). Mediation analyses showed that improvements in TTE cycling were indirectly related to expectancy and decline in blood bicarbonate when NaHCO3 was administered in solution but not capsules

Anomalous jumping in a double-well potential

Noise induced jumping between meta-stable states in a potential depends on the structure of the noise. For an $\alpha$-stable noise, jumping triggered by single extreme events contributes to the transition probability. This is also called Levy flights and might be of importance in triggering sudden changes in geophysical flow and perhaps even climatic changes. The steady state statistics is also influenced by the noise structure leading to a non-Gibbs distribution for an $\alpha$-stable noise.Comment: 11 pages, 7 figure