Two new concepts have been identified for direct steam generating solar fields that charge a two-tank molten salt storage system. The use of both supercritical and superheated subcritical steam is proposed, and discussed in practical terms and with regards to thermodynamic issues of heat transfer to the salt. Both concepts are found to allow significantly higher hot-tank temperatures than solar...

It was proved in [25] that for a contact Riemannian manifold with non-integrable almost complex structure, the Yamabe problem is subcritical in the sense that its Yamabe invariant is less than that of the Heisenberg group. In this paper we give a complete proof of the solvability of the contact Riemannian Yamabe problem in the subcritical case. These two results implies that the Yamabe problem ...

The effect of alkyl group substituents on the degradation kinetics of poly(alkyl methacrylates) namely poly (n-butyl methacrylate) (PBMA), poly (iso-propyl methacrylate) (PPMA), poly (ethyl methacrylate) (PEMA), and poly (methyl methacrylate) (PMMA) in supercritical and subcritical conditions was studied at various temperatures (250 – 375 o C). The molecular weight distributions were measured b...

We extend a technique of approximation of the long-term behavior of a supercritical stochastic epidemic model, using the WKB approximation and a Hamiltonian phase space, to the subcritical case. The limiting behavior of the model and approximation are qualitatively different in the subcritical case, requiring a novel analysis of the limiting behavior of the Hamiltonian system away from its dete...

Recent studies have shown that nanotwinned copper (NT Cu) exhibits a combination of high strength and moderate ductility. However, most engineering and structural applications would also require materials to have superior fracture toughness and prolonged subcritical fatigue crack growth life. The current study investigates the effect of twin density on the crack initiation toughness and stable ...

ÐThe need for readily biodegradable organic matter to support denitri®cation and enhanced biological phosphorus removal (EBPR) can be satis®ed using external or internal carbon sources. This paper examines the production and removal of volatile fatty acids (VFAs), mainly acetic acid, and other hydrolyzed products from sludge using hydrothermal treatment at subcritical (<3748C) and supercritical...

A novel continuous subcritical n-butane extraction technique for Camellia seed oil was explored. The fatty acid composition, physicochemical properties, and benzo[a]pyrene content of Camellia seed oil extracted using this subcritical technique were analyzed. Orthogonal experiment design (L9(34)) was adopted to optimize extraction conditions. At a temperature of 45 °C, a pressure of 0.5 MPa, a t...

Bursting behavior in neurons is a recurrent transition between a quiescent state and repetitive spiking. When the transition to repetitive spiking occurs via a subcritical Andronov–Hopf bifurcation and the transition to the quiescent state occurs via double limit cycle bifurcation, the burster is said to be of subcritical elliptic type. When the fast subsystem is near a Bautin (generalized Hopf...

We study a natural dependent percolation model introduced by Häggström. Consider subcritical Bernoulli bond percolation with a fixed parameter p < pc. We define a dependent site percolation model by the following procedure: for each bond cluster, we colour all vertices in the cluster black with probability r and white with probability 1− r , independently of each other. On the square lattice, d...

A method using heated and superheated (subcritical) water is described for rapid prediction of long-term desorption rates from contaminated geosorbents. Rates of contaminant release are measured at temperatures between 75 and 150 degrees C using a dynamic water desorption technique. The subcritical desorption rate data are then modeled to calculate apparent activation energies, and these activa...