Australian equity warrants: Are retail investors getting a fair go?

The AS X has two functionally similar markets for contingent equity contracts - a warrants market principally serving retail investors and an ETO market that may be used by retail and professional traders. Using pricing and volatility comparisons, this study finds that warrants are generally overpriced and are significantly dearer than their ETO equivalents. The paper recommends that short selling be allowed in the warrants market in order to reduce the pricing differentials and end the systematic exploitation of retail warrant investors by warrant issuers

The Human Transformation of Rapa Nui (Easter Island, Pacific Ocean)

Rapa Nui (Easter Island) has become widely known as a case study of human-induced environmental catastrophe resulting in cultural collapse. The island\u27s alleged ecocide is offered as a cautionary tale of our own environmental recklessness. The actual archaeological and historical record for the island reveals that while biodiversity loss unfolded, the ancient Polynesians persisted and succeeded. Demographic collapse came with epidemics of Old World diseases introduced by European visitors. In this paper, we outline the process of prehistoric landscape transformation that took place on Rapa Nui. This process includes the role of humans using fire to remove forest and convert to land for agricultural use as well as the impact of introduced rats (Rattus exulans) as agents that depressed recruitment of native vegetation and contributed to the island\u27s deforestation. For humans, the transformation of the landscape improved productivity. Burning of palms and other trees provided a short-term addition of nutrients to poor soils. Rock mulch and agricultural enclosures solved problems of cultivation and mitigated risk in an uncertain environment. The environmental transformation of Rapa Nui, while a tragedy in terms of biodiversity, was a success for a sustainable Polynesian subsistence economy

Triumph of the Commons: Sustainable Community Practices on Rapa Nui (Easter Island)

The history of Rapa Nui (Easter Island) has long been framed as a parable for how societies can fail catastrophically due to the selfish actions of individuals and a failure to wisely manage common-pool resources. While originating in the interpretations made by 18th-century visitors to the island, 20th-century scholars recast this narrative as a “tragedy of the commons,” assuming that past populations were unsustainable and selfishly overexploited the limited resources on the island. This narrative, however, is now at odds with a range of archaeological, ethnohistoric, and environmental evidence. Here, we argue that while Rapa Nui did experience large-scale deforestation and ecological changes, these must be contextualized given past land-use practices on the island. We provide a synthesis of this evidence, showing that Rapa Nui populations were sustainable and avoided a tragedy of the commons through a variety of community practices. We discuss this evidence in the context of Elinor Ostrom’s “core design principles” for sustainable communities and argue that Rapa Nui provides a model for long-term sustainability

Historical Reconstruction Reveals Recovery in Hawaiian Coral Reefs

Coral reef ecosystems are declining worldwide, yet regional differences in the trajectories, timing and extent of degradation highlight the need for in-depth regional case studies to understand the factors that contribute to either ecosystem sustainability or decline. We reconstructed social-ecological interactions in Hawaiian coral reef environments over 700 years using detailed datasets on ecological conditions, proximate anthropogenic stressor regimes and social change. Here we report previously undetected recovery periods in Hawaiian coral reefs, including a historical recovery in the MHI (~AD 1400–1820) and an ongoing recovery in the NWHI (~AD 1950–2009+). These recovery periods appear to be attributed to a complex set of changes in underlying social systems, which served to release reefs from direct anthropogenic stressor regimes. Recovery at the ecosystem level is associated with reductions in stressors over long time periods (decades+) and large spatial scales (>103 km2). Our results challenge conventional assumptions and reported findings that human impacts to ecosystems are cumulative and lead only to long-term trajectories of environmental decline. In contrast, recovery periods reveal that human societies have interacted sustainably with coral reef environments over long time periods, and that degraded ecosystems may still retain the adaptive capacity and resilience to recover from human impacts

Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control

Public Service Company of Colorado and ADA Technologies, Inc. have performed a study of the injection of activated carbon for the removal of vapor-phase mercury from coal-fired flue gas streams. The project was completed under contract to the US Department of Energy's National Energy Technology Laboratory, with contributions from EPRI and Public Service Company. The prime contractor for the project was Public Service Company, with ADA Technologies as the major subcontractor providing technical support to all aspects of the project. The research and development effort was conducted in two phases. In Phase I a pilot facility was fabricated and tests were performed using dry carbon-based sorbent injection for mercury control on a coal-fired flue gas slipstream extracted from an operating power plant. Phase II was designed to move carbon injection technology towards commercial application on coal-fired power plants by addressing key reliability and operability concerns. Phase II field work included further development work with the Phase I pilot and mercury measurements on several of PSCo's coal-fired generating units. In addition, tests were run on collected sorbent plus fly ash to evaluate the impact of the activated carbon sorbent on the disposal of fly ash. An economic analysis was performed where pilot plant test data was used to develop a model to predict estimated costs of mercury removal from plants burning western coals. Testing in the pilot plant was undertaken to quantify the effects of plant configuration, flue gas temperature, and activated carbon injection rate on mercury removal. All three variables were found to significantly impact the mercury removal efficiency in the pilot. The trends were clear: mercury removal rates increased with decreasing flue gas temperature and with increasing carbon injection rates. Mercury removal was much more efficient with reverse-gas and pulse-jet baghouse configurations than with an ESP as the particulate control device. The native fly ash of the host unit provided significant mercury removal capacity, so that the activated carbon sorbent served as an incremental mercury removal mechanism. Tests run to characterize the waste product, a combination of fly ash and activated carbon on which mercury was present, showed that mercury and other RCRA metals of interest were all below Toxic Characteristic Leaching Procedure (TCLP) regulatory limits in the leachate. The presence of activated carbon in the fly ash was shown to have an effect on the use of fly ash as an additive in the manufacture of concrete, which could limit the salability of fly ash from a plant where activated carbon was used for mercury control

The Pukao of Rapa Nui (Easter Island, Chile)

Structure from motion (SfM) mapping is a photogrammetric technique that offers a cost-effective means of creating three-dimensional visual representations from overlapping digital photographs. The technique has seen increasing uses for documenting the archaeological record. We demonstrate the utility of SfM through a study of the form of red scoria bodies known as pukao from Rapa Nui (Easter Island, Chile). We study 50 pukao that once adorned the massive statues (moai) of Rapa Nui, and compare them to 13 additional pukao located in Puna Pau: the island’s red scoria pukao quarry. Through SfM, we demonstrate that the majority of these bodies have petroglyphs and other surface features that are relevant to archaeological explanation and are currently at risk of continued degradation

Using Structure from Motion Mapping to Record and Analyze Details of the Colossal Hats (Pukao) of Monumental Statues on Rapa Nui (Easter Island)

Structure from motion (SfM) mapping is a photogrammetric technique that offers a cost-effective means of creating three-dimensional (3-D) visual representations from overlapping digital photographs. The technique is now used more frequently to document the archaeological record. We demonstrate the utility of SfM by studying red scoria bodies known as pukao from Rapa Nui (Easter Island, Chile). We created 3-D images of 50 pukao that once adorned the massive statues (moai) of Rapa Nui and compare them to 13 additional pukao located in Puna Pau, the island’s red scoria pukao quarry. Through SfM, we demonstrate that the majority of these bodies have petroglyphs and other surface features that are relevant to archaeological explanation and are currently at risk of continued degradation

Integrated dry NO{sub x}/SO{sub 2} emissions control system. Final report, Volume 1: Public design

The U.S. Department of Energy (DOE)/Pittsburgh Energy Technology Center (PETC) and the Public Services Company of Colorado (PSCo) signed the cooperative agreement for the Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System in March 1991. This project integrates various combinations of five existing and emerging technologies onto a 100 MWe, down-fired, load-following unit that burns pulverized coal. The project is expected to achieve up to 70% reductions in both oxides of nitrogen (NO{sub x}) and sulfur dioxide (SO{sub 2}) emissions. Various combinations of low-NO{sub x} burners (LNBs), overfire air (OFA) ports, selective non-catalytic reduction (SNCR), dry sorbent injection (DSI) using both calcium- and sodium-based reagents, and flue-gas humidification are expected to integrate synergistically and control both NO{sub x} and SO{sub 2} emissions better than if each technology were used alone. For instance, ammonia emissions from the SNCR system are expected to reduce NO{sub 2} emissions and allow the DSI system (sodium-based reagents) to achieve higher removals of SO{sub 2}. Unlike tangentially or wall-fired units, down-fired require substantial modification to their pressure parts to retrofit LNBs and OFA ports, substantially increasing the cost of retrofit. Conversely, the retrofitting of SNCR, DSI, or humidification systems does not require any major boiler modifications and are easily retrofitted to all boiler types. However, existing furnace geometry and flue-gas temperatures can limit their placement and effectiveness. In particular, SNCR requires injecting the SNCR chemicals into the furnace where the temperature is within a very narrow temperature range