Macartney Rose Control Systems.

4 p

Improvement of Gulf Cordgrass Range with Burning or Shredding

Shredding or burning during the spring, summer, or winter increased the live gulf cordgrass standing crop, decreased the dead gulf cordgrass standing crop, and increased the percentage of plants supporting inflorescences by the end of the first growing season after treatment on a clay site. The most favorable growth responses resulted from treatment in the spring, apparently because subsequent rainfall was greater than following summer treatments. Shredding generally stimulated herbaceous yields more than burning. Presumably the heavy mulch cover after shredding improved moisture relationships relative to the bare surface following fires. Burning or shredding resulted in less favorable responses on a saline fine sand than on the clay site. However, on the saline fine sand as on the clay site, shredding promoted production of gulf cordgrass more than did burning. Both methods are effective for improving gulf cordgrass range for livestock grazing, but burning is apparently the more economical alternative.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Spintronics: Fundamentals and applications

Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio