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The hydrodynamics in an unbaffled stirred vessel were simulated in order to highlight the effect of gravity on pressure and velocity distributions. Two fluids with different viscosity were studied for the laminar and turbulent flow regimes, respectively. The simulation results were compared with experimental data from the literature. Results indicate that for the higher‐viscosity fluid, gravity only affects static pressure and that the effects of gravity on velocity and dynamic pressure are negligible. For the lower‐viscosity fluid, however, gravity imposes a pronounced impact on static pressure, dynamic pressure, velocity, and turbulent kinetic energy. These findings indicate that careful consideration is necessary for the role that gravity plays in the study of free‐surface hydrodynamics in unbaffled stirred vessels. 相似文献
995.
L. A. Nazarova L. A. Nazarov A. L. Karchevsky M. Vandamme 《Journal of Mining Science》2015,51(4):666-672
In the framework of the developed and implemented nonlinear geomechanical model of a coal bed having block structure, describing gas inflow, the authors propose the method for quantitative estimate of gas content as well as diffusion and mass exchange coefficients based on solution of inverse problems using pressure measurements taken in shut-in borehole in the “pressure drop” mode. Besides the main function, the set problem had an auxiliary objective function with the less number of arguments. Numerical experiments with synthetic input data yield that the auxiliary objective function has a number of local minimums. The authors also put forward a technique of finding global minimum that provides the set problem solution. 相似文献
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997.
Zorina M. A. Karabanalov M. S. Loginov Yu. N. Lobanov M. L. 《Metal Science and Heat Treatment》2022,64(1-2):3-8
Metal Science and Heat Treatment - Special features of deformation and recrystallization textures in a copper capillary tube produced by drawing and subjected to annealing in a vacuum furnace at... 相似文献
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Nametala Ciniro A. L. Faria Wandry R. Pereira Júnior Benvindo R. 《Genetic Programming and Evolvable Machines》2022,23(2):193-223
Genetic Programming and Evolvable Machines - The Bayesian Optimization Algorithm (BOA) is one of the most prominent Estimation of Distribution Algorithms. It can detect the correlation between... 相似文献
1000.
L. Cattaneo V. Lopreiato F. Piccioli-Cappelli E. Trevisi A. Minuti 《Journal of dairy science》2021,104(7):8228-8242
The dry-off of dairy cows represents an important phase of the lactation cycle, influencing the outcome of the next lactation. Among the physiological changes, the severity of the inflammatory response can vary after the dry-off, and this response might have consequences on cow adaptation in the transition period. The plasma protein profile is a diagnostic tool widely used in humans and animals to assess the inflammatory status and predict the outcome of severe diseases. The albumin-to-globulin ratio (AG) can represent a simple and useful proxy for the inflammatory condition. In this study, we investigated the relationship between AG before dry-off and inflammation, metabolic profile, and performance of 75 Holstein dairy cows. Blood samples were collected from ?62 (7 d before dry-off) to 28 d relative to calving (DFC) to measure metabolic profile biomarkers, inflammatory variables, and liver function. Daily milk yield in the first month of lactation was recorded. Milk composition, body condition score, fertility, and health status were also assessed. The AG calculated 1 wk before dry-off (?62 DFC) was used to retrospectively group cows into tertiles (1.06 ± 0.09 for HI, 0.88 ± 0.04 for IN, and 0.72 ± 0.08 for LO). Data were subjected to ANOVA using the PROC MIXED program in SAS software. Differences among groups observed at ?62 DFC were almost maintained throughout the period of interest, but AG peaked before calving. According to the level of acute-phase proteins (haptoglobin, ceruloplasmin, albumin, cholesterol, retinol-binding protein), bilirubin, and paraoxonase, a generally overall lower inflammatory condition was found in HI and IN than in the LO group immediately after the dry-off but also after calving. The HI cows had greater milk yield than LO cows, but no differences were observed in milk composition. The somatic cell count reflected the AG ratio trend, with higher values in LO than IN and HI either before dry-off or after calving. Fertility was better in HI cows, with fewer days open and services per pregnancy than IN and LO cows. Overall, cows with high AG before dry-off showed an improved adaptation to the new lactation, as demonstrated by a reduced systemic inflammatory response and increased milk yield than cows with low AG. In conclusion, the AG ratio before dry-off might represent a rapid and useful proxy to evaluate the innate immune status and likely the ability to adapt while switching from the late lactation to the nonlactating phase and during the transition period with emphasis on early lactation. 相似文献