Optimal Replacement, Retrofit, And Management Of A Fleet Of Assets Under Regulations Of An Emissions Trading System

This thesis presents the development of a model for parallel replacement and improvement for a fleet of assets to minimize both the economic costs and greenhouse gas (GHG) emissions where the emissions are limited by cap-and-trade. The firm which owns the assets has the options of using the assets, putting them in inventory, improving them, or salvaging them. Different technological types and their performances have been considered for assets. The firm has the option of purchasing new assets from varying technologies and/or improving its existing assets to a higher-performance type. Moreover, the model considers the possibility of both banking the emission allowances and trading them in the market. The model was later used with data of a fleet of excavators in Ontario, Canada. The use of this model could help emitter firms to simultaneously manage the emissions and costs of their fleet of assets in a jurisdiction regulated by cap-and-trade.

Optimal Replacement, Retrofit, And Management Of A Fleet Of Assets Under Regulations Of An Emissions Trading System

This thesis presents the development of a model for parallel replacement and improvement for a fleet of assets to minimize both the economic costs and greenhouse gas (GHG) emissions where the emissions are limited by cap-and-trade. The firm which owns the assets has the options of using the assets, putting them in inventory, improving them, or salvaging them. Different technological types and their performances have been considered for assets. The firm has the option of purchasing new assets from varying technologies and/or improving its existing assets to a higher-performance type. Moreover, the model considers the possibility of both banking the emission allowances and trading them in the market. The model was later used with data of a fleet of excavators in Ontario, Canada. The use of this model could help emitter firms to simultaneously manage the emissions and costs of their fleet of assets in a jurisdiction regulated by cap-and-trade.

Determination of the Shear Strength of Rockfill from Small-Scale Laboratory Shear Tests: A Critical Review

Determining the shear strength of rockfill is a key task for the design and stability analysis of rockfill structures. When direct shear tests are performed, the well-established ASTM standard requires that specimen width and thickness must be at least 10 and 6 times the maximum particle size (dmax), respectively. When the value of dmax is very large, performing such tests in laboratory with field rockfill becomes difficult or impossible. Four scaling-down techniques were proposed in the past to obtain a modeled sample excluding oversize particles: scalping, parallel, replacement, and quadratic. It remains unclear which of the four scaling-down techniques yields reliable shear strength of field rockfill. In this paper, an extensive review is presented on existing experimental results to analyze the capacity of each scaling-down technique to determine the field rockfill shear strength. The analyses show that previous researches followed an inappropriate methodology to validate or invalidate a scaling-down technique through a direct comparison between the shear strengths of modeled and field samples. None of the four scaling-down techniques was shown to be able or unable to predict the field rockfill shear strength by extrapolation. The analyses further show that the minimum ratios of specimen size to dmax dictated by well-established standards are largely used but are too small to eliminate the specimen size effect. In most cases, this practice results in shear strength overestimation. The validity or invalidity of scaling-down techniques based on experimental results obtained by using the minimum ratios is uncertain. Recommendations are given for future studies.

Profundal oligochaete faunas (Annelida, Clitellata) in Japanese lakes

Thirty-eight species of oligochaetes (Annelida, Clitellata) belonging to five families were recorded from profundal bottoms of 50 freshwater lakes on Japanese islands. They were mostly widely distributed species, and the composition of fauna is basically explained by the scheme of Timm (2012), with parallel replacement of European species. Oxygen, temperature and surrounding fauna could be main factors determining the profundal fauna in the lakes. The lumbriculids (Styloscolex japonicus, Yamaguchia toyensis and Lumbriculus variegatus), haplotaxids (Haplotaxis gordioides) and enchytraeids (Marionina klaskisharum) were restricted to several deep and oligotrophic lakes located in Hokkaido and northern Honshu, where Rhyacodrilus komarovi often accompanied them. Limnodrilus hoffmeisteri was the commonest species, occurring irrespective of the trophic status and bottom temperature of the lake. Tubifex tubifex also occurred in wide trophic scale, but it has never been found in shallow eutrophic lakes where the bottom temperature exceeds 15°C, where L. hoffmeisteri, Branchiura sowerbyi and several Aulodrilus species were the main representatives.

Parallel replacement of the oxygenator that is not transferring oxygen: the PRONTO procedure

We present here a technique to replace a failed oxygenator by inserting a second oxygenator in parallel (PRONTO) within the cardiopulmonary bypass (CPB) circuit. Oxygenator failure is a potential hazard that may result in patient injury or death. Although failures are rare, safety surveys conducted over the last 25 years suggest that the incidence of oxygenator failures is on the rise. This emergency procedure may be easily applied to any standard CPB circuit with a few minor alterations. The technique is simple; it can be carried out rapidly. An important advantage of this technique is that it may be executed without interrupting blood flow to the patient, which may reduce the incidence of patient injury or death.