61,034 research outputs found
Seasonal and Vertical Distributions of Planthoppers (Homoptera: Fulgoroidea) Within a Black Walnut Plantation
Information on the seasonal and vertical distributions of 34 species (eight families) of planthoppers was obtained from window trap collections in a North Carolina black walnut plantation in 15 and 1978. The most commonly collected species were Acanalonia conica (Acanaloniidael. Liburniella ornata (Delphacidae), Oliarus ecologus (Cixiidae), and O. quinquelineatus
Study to investigate and evaluate means of optimizing the Ku-band combined radar/communication functions for the space shuttle
The performance of the space shuttle orbiter's Ku-Band integrated radar and communications equipment is analyzed for the radar mode of operation. The block diagram of the rendezvous radar subsystem is described. Power budgets for passive target detection are calculated, based on the estimated values of system losses. Requirements for processing of radar signals in the search and track modes are examined. Time multiplexed, single-channel, angle tracking of passive scintillating targets is analyzed. Radar performance in the presence of main lobe ground clutter is considered and candidate techniques for clutter suppression are discussed. Principal system parameter drivers are examined for the case of stationkeeping at ranges comparable to target dimension. Candidate ranging waveforms for short range operation are analyzed and compared. The logarithmic error discriminant utilized for range, range rate and angle tracking is formulated and applied to the quantitative analysis of radar subsystem tracking loops
Transport in coupled graphene-nanotube quantum devices
We report on the fabrication and characterization of all-carbon hybrid
quantum devices based on graphene and single-walled carbon nanotubes. We
discuss both, carbon nanotube quantum dot devices with graphene charge
detectors and nanotube quantum dots with graphene leads. The devices are
fabricated by chemical vapor deposition growth of carbon nanotubes and
subsequent structuring of mechanically exfoliated graphene. We study the
detection of individual charging events in the carbon nanotube quantum dot by a
nearby graphene nanoribbon and show that they lead to changes of up to 20% of
the conductance maxima in the graphene nanoribbon acting as a good performing
charge detector. Moreover, we discuss an electrically coupled graphene-nanotube
junction, which exhibits a tunneling barrier with tunneling rates in the low
GHz regime. This allows to observe Coulomb blockade on a carbon nanotube
quantum dot with graphene source and drain leads
Inventory of forest and rangeland resources, including forest stress
The author has identified the following significant results. Road systems being developed within the Manitou, Colorado area for human habitation are readily discernible on the S192 normal-color photographs. These are dirt roads, some of which are about 20 feet wide. These data should provide the District Ranger of the Pike National Forest required information on the size and extent of these developing areas, information which he does not now have but is required for total management of the District
Inventory of forest and rangeland resources, including forest stress
There are no author-identified significant results in this report
Inventory of forest and rangeland resources, including forest stress
There are no author-identified significant results in this report
Inventory of forest and rangeland resources, including forest stress
There are no author-identified significant results in this report
Inventory of forest and rangeland resources, including forest stress
There are no author-identified significant results in this report
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