Trajectory Tracking Control of a Quadrotor Aerial Vehicle in the Presence of Input Constraints

International Journal of Control, Automation and Systems - In this paper, we address the control problem of a Quadrotor Aerial Vehicle (QAV) in the presence of the input constraints. For this...     

Glycerol conversion over palladium- and alumina-impregnated KIT-6 for the production of gasoline range hydrocarbons

The use of large pore size catalyst with high surface area is explored in this work by using KIT-6 silica-based mesoporous material for the conversion of glycerol to higher hydrocarbons. Palladium and alumina were incorporated into the KIT-6 for providing Lewis acid sites and removal of oxygen. A decrease in surface area and pore diameter was observed with the incorporation of alumina and palladium on KIT-6. Ethanol was used as diluent as glycerol is viscous in nature and has issues related to flow in the preheater. An increase in the conversion was observed from 78 to 93.7% with the increase in temperature from 400 to 700 °C; however, the liquid yield was observed to decrease above 600 °C. GC (FID) analysis showed that the maximum values (38.9%) for gasoline range hydrocarbons fraction were obtained at 550 °C. No significant effect was observed on the liquid-phase yield with the addition of palladium; however, it was observed that the liquid product obtained in the presence of palladium has higher H/C ratio, indicating the formation of paraffinic compounds and removal of oxygen. GC/MS analysis showed the presence of mostly oxygenated long-chain hydrocarbons.     

The phantom of the matrix: Inverting the case on closure in Cole's model

In Closing the Case on Closure in Cole's Model Randall Jackson and Moss Madden critique my solution to the time-lagged regional input-output model. My rebuttal demonstrates that they: i) interpret my model incorrectly, ii) are inconsistent in their own specification, and iii) make inapplicable numerical comparisons between short- and long-term solutions. I show also iv) the correct solution to the totally closed model is neither trivial, nor singular, and v) this resolves the apparent paradox of infinite multipliers in a finite world. Moreover, vi) in my model, injecting exogenous demands equal to export earnings correctly reproduces the base output levels. The standard model does not meet this test. Received: 31 March 1999 / Accepted: 19 June 1999     

Regional issues in the Pacific Rim

Abstract. The economic space of the Pacific Rim, which is complex and dynamic, is now undergoing restructuring for survival and subsequent regional integration. This research note suggests four emerging regional issues which will be important for regional scientists in the Pacific Rim in the 21st century. They are: 1) the role of global finance in the regional and national economy in reshaping the space economy and city regions in the Pacific Rim; 2) formation of inter-firm networks and inter-city networks; 3) regional innovation systems and regional growth in the Pacific Rim; and 4) emergence of the knowledge-based economy and new industrialization. In this dynamic and complex process of change in the Pacific Rim, an active role of regional scientists is required with respect to creative research on regional analysis, reappraisal of the region, development of new methodology and theory of regional growth.     

Random field characterization of CPTU soil behavior type index of Jiangsu quaternary soil deposits

Bulletin of Engineering Geology and the Environment - The soil behavior type index (I c) obtained from piezocone penetration tests (CPTU) has been widely applied in a series of geotechnical issues...     

Managing airport stormwater containing deicers: challenges and opportunities

Stormwater runoff at airports is a significant and costly issue, especially for the stormwater laden with deicing contaminants of high Biochemical Oxygen Demand (BOD) and aquatic toxicity. To reduce the loading of deicing constituents in stormwater and to manage the increasing pressure of tightening regulations, identifying fate and transport and evaluating environmental risks of deicing stormwater are of critical importance. In this review, the regulatory development of airport deicing stormwater management was first discussed, along with the milestone Airport Cooperative Research Program (ACRP) Report 14 publication. The deicer usage and fugitive losses can be reduced and the amount of deicer collected can be increased by having a better understanding of the fate and transport of deicing constituents in stormwater. As such, an overview and evaluation of the constituents of concern in deicers were provided to support the assessment of environmental impacts and mitigation recommendations. The state of knowledge of airport deicing stormwater management was then reviewed, which needs to be synthesized into a national guidance document. A guidebook and a decision tool for airports were proposed to adopt specific practical stormwater management strategies while balancing their priorities in environmental, economic, and social values against operational constraints. These challenges pose great opportunities to improve the current practices of airport deicing stormwater management.