Within populations of the seed beetle Callosobruchus maculatus (F.) (Coleoptera: Bruchidae), female longevity is positively correlated with fecundity, both phenotypically and genetically. Yet manipulations of egg‐laying rate (through deprivation of seeds or mates) consistently suggest a trade‐off between these traits. In this study, females were exposed to four levels of seed availability and the relationship between fecundity and longevity was examined both across and within environments. The expected trade‐off was observed across environments, as females with few or no seeds laid fewer eggs and lived longer than females with many seeds. Within environments, however, the relationship was inconsistent; individual longevity and fecundity were positively correlated when seeds were abundant, uncorrelated when seeds were few and negatively correlated when seeds were absent. Body mass at adult emergence was positively correlated with fecundity, but its effect was stronger when seeds were present than when they were absent. After the effects of mass were statistically controlled, longevity and fecundity remained positively correlated among females with many seeds and negatively correlated among those without seeds. Thus, even a single technique (phenotypic correlation) can produce divergent conclusions about the ‘cost of reproduction’ in insects. The reversal in the correlation appears to depend on variation in reproductive allocation; when seeds are scarce or absent, differences in reproductive effort among individuals may be large enough to overwhelm differences in resource acquisition.
Biomass
feedstocks contain inorganic compounds generally classified
as ash. The ash consists of compounds of potassium, calcium, magnesium,
silicon, phosphorus. and other elements. These elements have been
reported to influence both the pyrolysis reactions as well as the
destabilization of the pyrolysis oils during storage. The inorganic
elements have also been reported to deposit on catalyst surfaces during in situ catalytic pyrolysis leading to the eventual deactivation
of acidic catalysts such as zeolites. The deposition of inorganic
elements and their effects on formulated red mud (FRM) catalyst during in situ catalytic pyrolysis of pinyon juniper wood was investigated.
The inorganic elements were measured for the fresh, coked, and regenerated
catalysts. The BET specific surface area of the FRM catalyst decreased
from 76 m2/g for the fresh catalyst to 53 m2/g for the stable regenerated catalyst. After three regenerations,
the BET specific surface area stabilized at 53 m2/g and
remained constant after all other regenerations. Potassium, calcium,
magnesium, and phosphorus were deposited on the catalyst. Potassium
deposition was linear with the number of regenerations while magnesium
and calcium depositions were initially rapid but leveled-off after
three regenerations of the catalyst. Phosphorus deposition was almost
linear, but the data were more scattered compared to that of potassium.
The potassium deposition was attributed to physical phenomenon whereas
calcium and magnesium depositions were more akin to chemical reactions
related to the loss of BET surface area of the catalyst. The deposition
of these elements on the surface of the catalyst did not deactivate
it. After each catalyst regeneration, the oil yield was not significantly
affected and the oil oxygen content and viscosity decreased slightly.
This clearly showed that formulated red mud is a robust catalyst suitable
for in situ catalytic fast pyrolysis of biomass.
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