26 research outputs found
Refractory oxide insulated thermocouple designed and analyzed for high temperature applications
Study establishes design criteria for constructing high temperature thermocouple to measure nuclear fuel pin temperature. The study included a literature search to determine the compatibility of material useful for thermocouples, a hot zone error analysis, and a prototype design for hot junction and connector pin connections
International Geomagnetic Reference Field: the thirteenth generation
In December 2019, the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group (V-MOD) adopted the thirteenth generation of the International Geomagnetic Reference Field (IGRF). This IGRF updates the previous generation with a definitive main field model for epoch 2015.0, a main field model for epoch 2020.0, and a predictive linear secular variation for 2020.0 to 2025.0. This letter provides the equations defining the IGRF, the spherical harmonic coefficients for this thirteenth generation model, maps of magnetic declination, inclination and total field intensity for the epoch 2020.0, and maps of their predicted rate of change for the 2020.0 to 2025.0 time period
Hydration and sweating responses to hot-weather football competition
PubMedID: 21029200During a football match played in warm (34.3 ± 0.6 °C), humid (64 ± 2% rh) conditions, 22 male players had their pre-match hydration status, body mass change, sweat loss and drinking behavior assessed. Pre-match urine specific gravity (1.012 ± 0.006) suggested that all but three players commenced the match euhydrated. Players lost 3.1 ± 0.6 L of sweat and 45 ± 9 mmol of sodium during the 90-min match and replaced 55 ± 19% of their sweat losses and hence by the end of the game were 2.2 ± 0.9% lighter. The water volume consumed during the game was highly variable (1653 ± 487 mL; 741-2387 mL) but there was a stronger relationship between the estimated pre-game hydration status and water volume consumed, than between sweat rate and water volume consumed. In a second match, with the same players 2 weeks later in 34.4 ± 0.6 °C, 65 ± 3% rh, 11 players had a sports drink available to them before and during the match in addition to water. Total drink volume consumed during the match was the same, but approximately half the volume was consumed as sports drink. The results indicate that substantial sweat water and electrolyte losses can occur during match play in hot conditions and a substantial water and sodium deficit can occur in many players even when water or sports drink is freely available. © 2010 John Wiley & Sons A/S
Effect of hot environmental conditions on physical activity patterns and temperature response of football players
PubMedID: 21029201Heat stress may contribute to decreased match performance when football is played in extreme heat. This study evaluated activity patterns and thermal responses of players during soccer matches played in different environmental conditions. Non-acclimatized soccer players (n=11, 20±2 years) played two matches in conditions of moderate heat (MH) and high heat (HH) index. Core temperature (Tc) and physical performance were measured using a telemetric sensor and a global positioning system, respectively. The average ambient temperature and relative humidity were MH 34±1 °C and 38±2%; HH 36±0 °C and 61±1%. Peak Tc in the MH match was 39.1±0.4 °C and in the HH match it was 39.6±0.3 °C. The total distance covered in the first and second halves was 4386±367 and 4227±292 m for the MH match and 4301±487 and 3761±358 m for the HH match. Players covered more distance (P<0.001) in the first half of the HH match than in the second half. In football matches played at high environmental temperature and humidity, the physical performance of the players may decrease due to high thermal stress. © 2010 John Wiley & Sons A/S
Hydration and sweating responses to hot-weather football competition
During a football match played in warm (34.3 AE 0.6 1C), humid (64 AE 2% rh) conditions, 22 male players had their pre-match hydration status, body mass change, sweat loss and drinking behavior assessed. Pre-match urine specific gravity (1.012 AE 0.006) suggested that all but three players commenced the match euhydrated. Players lost 3.1 AE 0.6 L of sweat and 45 AE 9 mmol of sodium during the 90-min match and replaced 55 AE 19% of their sweat losses and hence by the end of the game were 2.2 AE 0.9% lighter. The water volume consumed during the game was highly variable (1653 AE 487 mL; 741-2387 mL) but there was a stronger relationship between the estimated pre-game hydration status and water volume consumed, than between sweat rate and water volume consumed. In a second match, with the same players 2 weeks later in 34.4 AE 0.6 1C, 65 AE 3% rh, 11 players had a sports drink available to them before and during the match in addition to water. Total drink volume consumed during the match was the same, but approximately half the volume was consumed as sports drink. The results indicate that substantial sweat water and electrolyte losses can occur during match play in hot conditions and a substantial water and sodium deficit can occur in many players even when water or sports drink is freely available
Ionospheric Pc1 waves during a storm recovery phase observed by the China Seismo-Electromagnetic Satellite
Abstract
During the storm recovery phase on 27 August 2018, the China Seismo-Electromagnetic Satellite (CSES) detected Pc1 wave activities in both the Northern Hemisphere and Southern Hemisphere in the high-latitude, post-midnight ionosphere with a central frequency of about 2 Hz. Meanwhile, the typical Pc1 waves were simultaneously observed for several hours by the Sodankylä Geophysical Observatory (SGO) stations on the ground. In this paper, we study the propagation characteristics and possible source regions of those waves. Firstly, we find that the Pc1 waves observed by the satellites exhibited mixed polarisation, and the wave normal is almost parallel with the background magnetic field. The field-aligned Poynting fluxes point downwards in both hemispheres, implying that the satellites are close to the wave injection regions in the ionosphere at about L=3. Furthermore, we also find that the estimated position of the plasmapause calculated by models is almost at L=3. Therefore, we suggest that the possible sources of waves are near the plasmapause, which is consistent with previous studies in that the outward expansion of the plasmasphere into the ring current during the recovery phase of geomagnetic storms may generate electromagnetic ion cyclotron (EMIC) waves, and these EMIC waves propagate northwards and southwards along the background magnetic field to the ionosphere at about L=3. Additionally, the ground station data show that Pc1 wave power attenuates with increasing distance from L=3, supporting the idea that the CSES observes the wave activities near the injection region. The observations are unique in that the Pc1 waves are observed in the ionosphere in nearly conjugate regions where transverse Alfvén waves propagate down into the ionosphere