Quantifying the economic competitiveness of cellulosic biofuel pathways under uncertainty and regional sensitivity

The revised Renewable Fuel Standard requires the annual blending of 16 billion gallons of cellulosic biofuel by 2022 from zero gallons in 2009. The necessary capacity investments have been underwhelming to date, however, and little is known about the likely composition of the future cellulosic biofuel industry as a result. This dissertation develops a framework for identifying and analyzing the industry\u27s likely future composition while also providing a possible explanation for why investment in cellulosic biofuels capacity has been low to date. The results of this dissertation indicate that few cellulosic biofuel pathways will be economically competitive with petroleum on an unsubsidized basis. Of five cellulosic biofuel pathways considered under 20-year price forecasts with volatility, only two achieve positive mean 20-year net present value (NPV) probabilities. Furthermore, recent exploitation of U.S. shale gas reserves and the subsequent fall in U.S. natural gas prices have negatively impacted the economic competitiveness of all but two of the cellulosic biofuel pathways considered; only two of the five pathways achieve substantially higher 20-year NPVs under a post-shale gas economic scenario relative to a pre-shale gas scenario. The economic competitiveness of cellulosic biofuel pathways with petroleum is reduced further when considered under price uncertainty in combination with realistic financial assumptions. This dissertation calculates pathway-specific costs of capital for five cellulosic biofuel pathway scenarios. The analysis finds that the large majority of the scenarios incur costs of capital that are substantially higher than those commonly assumed in the literature. Employment of these costs of capital in a comparative TEA greatly reduces the mean 20-year NPVs for each pathway while increasing their 10-year probabilities of default to above 80% for all five scenarios. Finally, this dissertation quantifies the economic competitiveness of six cellulosic biofuel pathways being commercialized in eight different U.S. states under price uncertainty, utilization of pathway-specific costs of capital, and region-specific economic factors. 10-year probabilities of default in excess of 60% are calculated for all eight location scenarios considered, with default probabilities in excess of 98% calculated for seven of the eight. Negative mean 20-year NPVs are calculated for seven of the eight location scenarios

Learning and Memory in the Port Jackson Shark, Heterodontus portusjacksoni

Basic understanding of the fundamental principles and mechanisms involved in learning is lacking for elasmobranch fishes. Our aim in this study was to experimentally investigate the learning and memory capacity of juvenile Port Jackson sharks, Heterodontus portusjacksoni. Sharks (N = 30) were conditioned over a 19-day period to associate an underwater LED light or stream of air-bubbles [conditioned stimulus (CS)] with a food reward [unconditioned stimulus (US)], using three procedures (delay, trace and control). During experiments, the CS signalled at a random time between 180 and 300 s for 30 s (six times per day). For the delay the US overlapped in time with the CS, for the trace the US delivered 10 s after the CS and for our control the US was delivered at random time between 180 and 300 s after the CS. H. portusjacksoni sharks trained in all procedures improved consistently in their time to obtain food, indicative of Pavlovian learning. Importantly, the number of sharks in the feeding area 5 s prior to CS onset did not change over time for any procedures. However, significantly more sharks were present 5 s after CS onset for delay for both air-bubble and light CS. Sharks trained in the delay and trace procedures using air-bubbles as the CS also displayed significantly more anticipatory behaviours, such as turning towards the CS and biting. Sharks trained with the light CS did not exhibit such behaviours; however, trace procedural sharks did show a significant improvement in moving towards the CS at its onset. At 20 and 40 days after the end of the conditioning experiments, some sharks were presented the CS without reward. Two sharks trained in the delay procedure using air-bubbles as the CS exhibited biting behaviours: one at 20 and the other at 40 days. This study demonstrates that H. portusjacksoni have the capacity to learn a classical conditioning procedure relatively quickly (30 trials during 5 days) and associate two time-separated events and retention of learnt associations for at least 24 h and possibly up to 40 days