We establish a priori bounds, existence and qualitative behaviour of positive radial solutions in annuli for a class of nonlinear systems driven by Pucci extremal operators and Lane-Emden coupling in the superlinear regime. Our approach is purely nonvariational. It is based on the shooting method, energy functionals, spectral properties, and on a suitable criteria for locating critical points in annular domains through the moving planes method that we also prove.

The catch of Japanese butterfish, Psenopsis anomala in Taiwan is greater than those of any other nation; however, the biology, particularly the age and growth, of this economically important fish species is little known. This study describes the age and growth of P. anomala based on 734 specimens (340 females, 363 males, 31 unsexed) caught by trawl fishery in the north-eastern waters off Taiwan from March 2007 to July 2008. The age of specimens was estimated by counting the growth annuli in sagittal otoliths. The periodicity of annulus deposition on otolith was estimated to be one year with opaque zone deposited between July and August based on marginal increment analysis. The maximum age for both sexes was estimated to be ~4. The female portion of the population was dominated by the 3+ age class, while the male portion was dominated by the 2∞ age class. The parameters of the von Bertalanffy growth function with standard error estimated based on the observed length at age using a non-linear method are as follows: L∞ = 25.47 ± 0.65 cm, k = 0.30 ± 0.03 year−1, and t0 = −1.84 ± 0.16 year for females (n = 350), and L∞ = 22.39 ± 0.45 cm, k = 0.46 ± 0.04 year−1, and t0 = −1.38 ± 0.13 year for males (n = 378). The growth performances of P. anomala reported from different geographic regions were compared, and the potential influences of sample size distribution on the estimated growth parameters were further discussed.

Age and growth parameters were estimated for the deep-sea cardinalfish (Epigonus crassicaudus) from sagittal otoliths collected between 2012 and 2015 onboard commercial fishing vessels from the South-east Pacific off Chile between 33°04′S and 41°46′S. Von Bertalanffy growth parameters (VBGP) were estimated from assumed annual otolith growth zone counts. The verification of the first annulus of sagittal otoliths was determined by examining in detail daily micro-increments. These data helped inform the interpretation of the annual growth zones from transverse otolith sections. The von Bertalanffy growth model estimated to length-at-age data were asymptotic length (L∞) of 34.1 cm fork length (FL), a growth coefficient (k) of 0.1 cm/year and a t-zero (t0) of −0.85. The maximum ages observed were 67 and 65 years for female and male fish, respectively.

Phase change in ice-water systems in the geometry of horizontal cylindrical annulus with constant inner wall temperature and adiabatic outer wall is modeled with an enthalpy-based mixture model. Solidification and melting phenomena under different temperature conditions are analyzed through a sequence of numerical calculations. In the case of freezing of water, the importance of convection and conduction as well as the influence of cold pipe temperature on time for the complete solidification are examined. As for the case of melting of ice, the influence of the inner pipe wall temperature on the shape of the ice-water interface, the flow and temperature fields in the liquid, the heat transfer coefficients and the rate of melting are analyzed. The results of numerical calculations point to good qualitative agreement with the available experimental and other numerical results.