The purpose of this paper is to discuss a first-return integration process which yields the Lebesgue integral of a bounded
measurable function f: I → R defined on a compact interval I. The process itself, which has a Riemann flavor, uses the given function f and a sequence of partitions whose norms tend to 0. The “first-return” of a given sequence
is used to tag the intervals from the partitions. The main result of the paper is that under rather general circumstances
this first return integration process yields the Lebesgue integral of the given function f for almost every sequence
The strength of chemical bonds formed between eight rock-forming minerals and six bitumen samples were examined by heat-of-immersion
calorimetry. The materials were characterised by their physical and chemical properties. The amount of energy released by
the bitumen-mineral interaction was much larger than expected for an immersion reaction, exceeding usual values by a factor
of up to 102. An oxidation mechanism, catalysed at the mineral surface, is proposed to account for this observation, and trends in the
heat-of-immersion data are correlated with chemical properties of the bitumen and mineral samples.
Authors:A. Kidane, Y. Guan, P. Evans, M. Kaderbhai and R. Kemp
It is claimed, though not without dispute, that genetically engineered mammalian cells grow more slowly than their progenitor
cells because the recombinant gene system causes a metabolic burden. This was found to be the case for CHO cells transfected
with expression vectors forcytochrome b5. The slower growth was associated with lower metabolic activity measured by heat flux and mitochondrial activity (rhodamine
123 fluorescence). The calorimetric-respirometric ratio was similar for all cell types, implying that the greater fluxes of
glucose and glutamine in the recombinant cells was channelled to biosynthesis. This demand probably restricted the supply
of pyruvate to the mitochondria in these cells.
Authors:H. Fretwell, J. Duffy, M. Alam and R. Evans
In this paper we present our recent positron annihilation study of the liquid»solid phase boundary for CO2 confined in nanometer pores of VYCOR glass. We find that CO2 remains liquid in the pores far below the bulk freezing temperature and there is pronounced hysteresis between freezing and melting compared to that seen at the gas-liquid boundary in the pores. On freezing we see evidence of open space created in the pores. This leads to complex melting behaviour possibly involving the formation of gas-liquid interfaces. We see that frezing in the pores is totally irreversible, so that any solid which forms (no matter how small) remains stable up to the higher melting temperature. In contrast melting is more reversible (possibly indicating nucleation centres which permit immediate re-freezing). Finally, the pre-frozen state in the pores is different to the post-melted state.