Local-Correlation Based Zero-Equation Transition Model for Turbomachinery

In this paper, we present a new local-correlation based zero-equation transition model. The new model, which is derived from the local-correlation based one-equation gamma transition model (Menter, F. R., Smirnov, P. E., Liu, T., and Avancha, R., A One-Equation Local Correlation-Based Transition Model, Flow, Turbulence and Combustion, vol. 95, 2015, pp. 583619.), does not require any additional equation to be solved, by defining a new variable, which captures the turbulent kinetic energy and intermittency collectively. The new model only adds three more source terms to the existing transport equation of turbulent kinetic energy. Hence the new model is straightforward to implement in already existing RANS solvers and reduces the computational memory requirement as compared to the other transition models. The transition prediction capability of the new model is tested and compared against the one-equation gamma transition model, especially for turbomachinery applications, where bypass transition is the primary transition mechanism, using a standard flat plate test case, and S809 airfoil. Preliminary results show that the new zero-equation transition model produces satisfactory results in terms of transition-location prediction.

Chiral anomaly transition form factor of γ → 3π in nonlocal quark model

Chiral anomaly of gamma transition into three pions are studied in a framework of nonlocal chiral quark model. In the local limit the result is in agreement with chiral perturbative theory and reproducesWess-Zumino-Witten anomaly. Transition form factor of gamma into three pions in nonlocal quark model has a correction which vanishes in local limit.

Gamma Spectrometry Analysis of Natural Radionuclide Contents of Three Mushroom Species Commonly Grown in Benue State, Nigeria

The activity concentration and Annual Effective doses of 40K, 226Ra, and 232Th in some edible mushroom species (Cantharellus cibarius, Agaricus campestris, Termitomyces robustus) found in three Local Government Areas of Benue state-Nigeria were determined using Gamma Spectrometry; the 1460KeV gamma-radiation of 40K was used to determine the concentration of 40K, gamma transition energy of 1764.5KeV 214Bi was used to determine the concentration of 226R, while the gamma transition energy of 2614KeV 208TI was used to determine the concentration of 232Th. The activity concentration due to 226Ra, 232Th and 40K in the samples ranged from 10.06±1.6 - 14.19±3.01Bqkg-1; 10.88±2.65 to 15.38±4.30Bqkg-1and 202.31±1.4 to 318.44±3.20Bqkg-1 respectively; the highest activity due to 226Ra was found in Termitomyces robustus grown in Gboko; that due to 232Th was recorded in Agaricus campestris grown in Buruku L.G.A., while the highest activity concentration due to 40K was recorded in Termitomyces robustus found in Buruku. Generally, 40K recorded the highest activity concentration in each mushroom species examined. Annual Effective Dose from these species sampled ranges from 0.0006952mSvy-1 (in Makurdi- Termitomyces robustus species) - 0.0008467mSvy-1 (in Buruku Termitomyces robustus species). The average effective dose value of 0.00788±0.000186mSvy-1 obtained in this work is below the maximum permissible level established by ICRP (1996). Thus, these mushrooms species will not pose any apparent risk to human health.