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An integrated control and electromagnetic/antenna formulation is presented for evaluating the performance of a distributed antenna system as a function of formation geometry.
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The Design Standards outline preferred design practices, methods of analysis, loadings, factors of safety, and structural and equipment types for projects and/or designed construction by the Bureau of Reclamation. All Reclamation ...
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The Design Standards outline preferred design practices, methods of analysis, loadings, factors of safety, and structural and equipment types for projects and/or designed construction by the Bureau of Reclamation. All Reclamation design work should conform insofar as practicable to the Design Standards.
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Today's flexible and automated manufacturing technologies offers great advantages for small-batch and single-product production over hard automation. However, due to great variety of workpieces and manufacturing operations in indu...
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Today's flexible and automated manufacturing technologies offers great advantages for small-batch and single-product production over hard automation. However, due to great variety of workpieces and manufacturing operations in industries, automated and flexible fixture design and manufacturing is still the bottleneck in realization of a real agile manufacturing environment. In this research project, an integrated fixture design and manufacturing system called automated fixture design and formation system (AFDFS) for small-batch or single-product production will be developed. The whole system is divided into five sub-systems: Fixture layout planning system, Fixturing point planning system, Fixture configuration design system, Fixturing process simulation and verification system, Fixture formation system. This paper focuses on developing the algorithms and methods for automated fixture layout planning.
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In support of the NASA Lewis Modern Airfoils Ice Accretion Test Program, the University of Illinois at Urbana-Champaign provided expertise in airfoil design and aerodynamic analysis to determine the aerodynamic effect of ice accre...
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In support of the NASA Lewis Modern Airfoils Ice Accretion Test Program, the University of Illinois at Urbana-Champaign provided expertise in airfoil design and aerodynamic analysis to determine the aerodynamic effect of ice accretion on modern airfoil sections. The effort has concentrated on establishing a design/testing methodology for 'hybrid airfoils' or 'sub-scale airfoils,' that is, airfoils having a full-scale leading edge together with a specially designed and foreshortened aft section. The basic approach of using a full-scale leading edge with a foreshortened aft section was considered to a limited extent over 40 years ago. However, it was believed that the range of application of the method had not been fully exploited. Thus a systematic study was being undertaken to investigate and explore the range of application of the method so as to determine its overall potential.
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摘要 :
In support of the NASA Lewis Modern Airfoils Ice Accretion Test Program, the University of Illinois at Urbana-Champaign provided expertise in airfoil design and aerodynamic analysis to determine the aerodynamic effect of ice accre...
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In support of the NASA Lewis Modern Airfoils Ice Accretion Test Program, the University of Illinois at Urbana-Champaign provided expertise in airfoil design and aerodynamic analysis to determine the aerodynamic effect of ice accretion on modern airfoil sections. The effort has concentrated on establishing a design/testing methodology for "hybrid airfoils" or "sub-scale airfoils," that is, airfoils having a full-scale leading edge together with a specially designed and foreshortened aft section. The basic approach of using a full-scale leading edge with a foreshortened aft section was considered to a limited extent over 40 years ago. However, it was believed that the range of application of the method had not been fully exploited. Thus a systematic study was being undertaken to investigate and explore the range of application of the method so as to determine its overall potential.
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A new method for making NMR measurements has been developed that potentially can receive NMR signals from a precise distance into the geologic formation. It is based on the production of a toroidal region of homogeneous radial mag...
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A new method for making NMR measurements has been developed that potentially can receive NMR signals from a precise distance into the geologic formation. It is based on the production of a toroidal region of homogeneous radial magnetic field near the mid-plane between two magnets arranged axially so their fields oppose between them. NMR signals have been detected from such a region in the laboratory. Preliminary data have been extrapolated to the projected performance of a logging tool using superconducting magnets. The presence of cryogenic temperatures required for these magnets may make signal detection using SQUIDs a logical consideration. Preliminary comparison of normal and SQUID NMR detection shows that near the borehole (<18 in.) standard NMR detection is probably superior; at greater distances SQUID detection may be advantageous. Directional detection of the signal may allow fractures near the wellbore to be mapped. Use of SQUID detection may be useful for this application. (ERA citation 06:024108)
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This paper investigates the closed-loop dynamics of systems controlled via parallel estimators. This structure arises in formation flying problems when each spacecraft bases its control action on an internal estimate of the comple...
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This paper investigates the closed-loop dynamics of systems controlled via parallel estimators. This structure arises in formation flying problems when each spacecraft bases its control action on an internal estimate of the complete formation state. For LTI systems a separation principle shows that the necessary and sufficient conditions for overall system stability are more stringent than the single controller case; the controllers' open-loop dynamics necessarily appear in the closed-loop dynamics. Communication amongst the spacecraft can be used to specify the complete system dynamics and a framework for integrating the design of the communication links into the formation flying control design problem is presented.
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The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic...
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The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic formations. Geologic, engineering, and operational databases were developed for McElmo Dome in Colorado; St. Johns Dome in Arizona and New Mexico; and Jackson Dome in Mississippi. The three study sites stored a total of 2.4 billion t (46 Tcf) of CO{sub 2} equivalent to 1.5 years of power plant emissions in the US and comparable in size with the largest proposed sequestration projects. The three CO{sub 2} fields offer a scientifically useful range of contrasting geologic settings (carbonate vs. sandstone reservoir; supercritical vs. free gas state; normally pressured vs. overpressured), as well as different stages of commercial development (mostly undeveloped to mature). The current study relied mainly on existing data provided by the CO{sub 2} field operator partners, augmented with new geochemical data. Additional study at these unique natural CO{sub 2} accumulations could further help guide the development of safe and cost-effective design and operation methods for engineered CO{sub 2} storage sites.
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