In certain extremely low probability, severe accident scenarios which have been postulated for liquid metal cooled fast reactors, large bubble cavities containing fuel vapor and fission products transit a layer of coolant and release this material to the cover gas thereby presenting a contribution to an accident-specific source term. So that a more mechanistic assessment of these types of events can be developed, analyses have recently been performed to account for the heat and work transfer observed in out-of-reactor source term experiments conducted during the 1980’s for oxide fueled reactors in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory. In ten experiments, UO2 specimens were vaporized in pools of sodium, and for an additional number of benchmarking tests, in pools of water, for purposes of experimentally assessing the bubble transport characteristics of both types of pools. The current analyses present several firsts for these experiments: (a) a comparison of the bubble-to-coolant transfer rates; heat versus work, (b) a bubble-to-coolant heat transfer model accounting for how condensation and radiation heat transfer are affected by coolant selection; sodium versus water, and (c) an assessment of how both types of heat transfer influence the movement of aerosol-laden bubbles through the coolant pool. These analyses significantly extend previous evaluations of FAST experimental results by providing a more comprehensive model for determining how bubble-coolant interactions affect aerosol transport and, in this way, contribute to data base development associated with mechanistic assessments of the source term.

The theory of analytic functions and more specific p-valent functions, is one of the most fascinating topics in one complex variable. There are many remarkable theorems dealing with extremal problems for a class of p-valent functions on the unit disk U. Recently, many researchers have shown great interests in the study of differential operator. The objective of this paper is to define a new generalized derivative operator of p-valent analytic functions of fractional power in the open unit disk U. This operator generalized some well-known operators studied earlier, we mention some of them in the present paper. Motivation by the generalized derivative operator; we introduce and investigate two new subclasses of starlike p-valent analytic functions of fractional power with positive coefficients and starlike p-valent analytic functions of fractional power with negative coefficients, respectively. In addition, a sufficient condition will be obtained. Some corollaries are also pointed out. Moreover, we determine the extreme points of functions belong to the class.

Seed size is a key functional trait that affects plant fitness at the seedling stage and may

vary greatly with species fruit size, growth form and fecundity. Using structural equation

modelling (SEM) and correlated trait evolution analysis, we investigated the interaction network

between seed size and fecundity, postfire regeneration strategy, fruit size, plant height

and serotiny (on-plant seed storage) among 82 species of the woody shrub genus, Hakea,

with a wide spectrum of seed sizes (2–500 mg). Seed size is negatively correlated with fecundity,

while fire-killed species (nonsprouters) produce more seeds than resprouters

though they are of similar size. Seed size is unrelated to plant height and level of serotiny

while it scales allometrically with fruit size. A strong phylogenetic signal in seed size revealed

phylogenetic constraints on seed size variation in Hakea. Our analyses suggest a

causal relationship between seed size, fecundity and postfire regeneration strategy in

Hakea. These results demonstrate that fruit size, fecundity and evolutionary history have

had most control over seed size variation among Hakea species.

•This paper examines the ability of Libyan university students studying EFL to identify the language items which are called conjunctives and recognize their meanings and functions before they can benefit from them in their reading and writing skills