Hypersonic vehicles suffer from extreme aerodynamic heating during flights, especially around the area of leading edge due to its small curvature. Therefore, flush air data sensing(FADS) system has been developed to p...Hypersonic vehicles suffer from extreme aerodynamic heating during flights, especially around the area of leading edge due to its small curvature. Therefore, flush air data sensing(FADS) system has been developed to perform accurate measurement of the air data parameters. In the present study, the method to develop the FADS algorithms with fail-operational capability for a sharp-nosed hypersonic vehicle is provided. To be specific, the FADS system implemented with 16 airframe-integrated pressure ports is used as a case study. Numerical simulations of different freestream conditions have been conducted to generate the database for the FADS targeting in 2 ≤ Ma ≤ 5 and 0 km ≤ H ≤ 30 km. Four groups of neural network algorithms have been developed based on four different pressure port configurations, and the accuracy has been validated by 280 groups of simulations. Particularly, the algorithms based on the 16-port configuration show an excellent ability to serve as the main solver of the FADS, where 99. 5% of the angle-of-attack estimations are within the error band ±0. 2°. The accuracy of the algorithms is discussed in terms of port configuration. Furthermore, diagnosis of the system health is present in the paper. A fault-tolerant FADS system architecture has been designed, which is capable of continuously sensing the air data in the case that multi-port failure occurs, with a reduction in the system accuracy.展开更多
The bovine fatty acid desaturase (FADS) gene cluster consists of FADS1, FADS2, FADS3, and FADS6, which acts as key enzymes in fatty acid metabolism. Of these, the genetics effects of variants in FADS1, FADS2 and FADS3...The bovine fatty acid desaturase (FADS) gene cluster consists of FADS1, FADS2, FADS3, and FADS6, which acts as key enzymes in fatty acid metabolism. Of these, the genetics effects of variants in FADS1, FADS2 and FADS3 have been previously studied. However, the genetic effects of variants of FADS6 gene have not been studied. The aim of this study was to identify genetic variants in the bovine fatty acid desaturase 6 (FADS6) gene and study their association with fatty acid composition in Hanwoo cattle. Six genetic variants were observed, three each in intron 2 and exon 6 by DNA sequencing analyses. The association of genetic variants with fatty acid composition was evaluated in 90 Hanwoo steers. The variants were confirmed and the animals were genotyped by RFLP (Restriction Fragment Length Polymorphism) and AS-PCR (Allele Specific PCR) analyses. The analysis revealed that palmitoleic acid (C16:1n7) was associated with g.3391G > A, g.3660A > C and g.15657C > T, and stearic acid (C18:0) showed highly significant association with g.3660A > C segments. Both g.3391G > A, g.3660A > C also had strong additive and dominance effect for Palmitoleic acid, while g.3660A > C also had a strong dominance effect for stearic acid. These results could be useful for modulating fatty acid composition in beef and produce meat with higher monounsaturated fatty acid to saturated fatty acid ratio (MUFA/SFA), which had been shown to have positive health effect in humans.展开更多
Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the me...Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the methods which have been used to enhance sustainable exploitation of fisheries resources is the use of Fish Aggregating Devices (FADs). The study was conducted in two areas along the Kenyan coast which are: Msambweni in the southern part and Kuruwitu (Vipingo) in the northern part of the Kenyan coast. A combination of systematic site surveys: structured and semi structured interviews with key informants (community leaders and resource users);participant observations;descriptions of daily and seasonal time use;and analyses of secondary sources, such as fisheries records, was used to gather information and triangulate results. The perception of the community about FADs was determined by conducting a socio-economic survey before and after deploying FADs. Colonization and biomass survey around the deployed FADs was undertaken and fish associated with FADs was recorded. Results indicate that nine families of fish aggregated around FADs and at different distances. Catch and effort at FADs have been evaluated by monitoring catch data from fishers on daily basis after deployments.展开更多
文摘Hypersonic vehicles suffer from extreme aerodynamic heating during flights, especially around the area of leading edge due to its small curvature. Therefore, flush air data sensing(FADS) system has been developed to perform accurate measurement of the air data parameters. In the present study, the method to develop the FADS algorithms with fail-operational capability for a sharp-nosed hypersonic vehicle is provided. To be specific, the FADS system implemented with 16 airframe-integrated pressure ports is used as a case study. Numerical simulations of different freestream conditions have been conducted to generate the database for the FADS targeting in 2 ≤ Ma ≤ 5 and 0 km ≤ H ≤ 30 km. Four groups of neural network algorithms have been developed based on four different pressure port configurations, and the accuracy has been validated by 280 groups of simulations. Particularly, the algorithms based on the 16-port configuration show an excellent ability to serve as the main solver of the FADS, where 99. 5% of the angle-of-attack estimations are within the error band ±0. 2°. The accuracy of the algorithms is discussed in terms of port configuration. Furthermore, diagnosis of the system health is present in the paper. A fault-tolerant FADS system architecture has been designed, which is capable of continuously sensing the air data in the case that multi-port failure occurs, with a reduction in the system accuracy.
文摘The bovine fatty acid desaturase (FADS) gene cluster consists of FADS1, FADS2, FADS3, and FADS6, which acts as key enzymes in fatty acid metabolism. Of these, the genetics effects of variants in FADS1, FADS2 and FADS3 have been previously studied. However, the genetic effects of variants of FADS6 gene have not been studied. The aim of this study was to identify genetic variants in the bovine fatty acid desaturase 6 (FADS6) gene and study their association with fatty acid composition in Hanwoo cattle. Six genetic variants were observed, three each in intron 2 and exon 6 by DNA sequencing analyses. The association of genetic variants with fatty acid composition was evaluated in 90 Hanwoo steers. The variants were confirmed and the animals were genotyped by RFLP (Restriction Fragment Length Polymorphism) and AS-PCR (Allele Specific PCR) analyses. The analysis revealed that palmitoleic acid (C16:1n7) was associated with g.3391G > A, g.3660A > C and g.15657C > T, and stearic acid (C18:0) showed highly significant association with g.3660A > C segments. Both g.3391G > A, g.3660A > C also had strong additive and dominance effect for Palmitoleic acid, while g.3660A > C also had a strong dominance effect for stearic acid. These results could be useful for modulating fatty acid composition in beef and produce meat with higher monounsaturated fatty acid to saturated fatty acid ratio (MUFA/SFA), which had been shown to have positive health effect in humans.
文摘Marine fisheries in Kenya mainly comprise of the artisanal fishermen who use non-motorized boats. Competition of these dwindling resources has led to overfishing and degradation of coral reef ecosystems. One of the methods which have been used to enhance sustainable exploitation of fisheries resources is the use of Fish Aggregating Devices (FADs). The study was conducted in two areas along the Kenyan coast which are: Msambweni in the southern part and Kuruwitu (Vipingo) in the northern part of the Kenyan coast. A combination of systematic site surveys: structured and semi structured interviews with key informants (community leaders and resource users);participant observations;descriptions of daily and seasonal time use;and analyses of secondary sources, such as fisheries records, was used to gather information and triangulate results. The perception of the community about FADs was determined by conducting a socio-economic survey before and after deploying FADs. Colonization and biomass survey around the deployed FADs was undertaken and fish associated with FADs was recorded. Results indicate that nine families of fish aggregated around FADs and at different distances. Catch and effort at FADs have been evaluated by monitoring catch data from fishers on daily basis after deployments.
