An Archeological Survey of a Realignment of the Proposed Wateree-Orangeburg 230 KV Transmission Line and an Archeological Testing Program for 38CL29, 38CL37 and 38CL41

https://scholarcommons.sc.edu/archanth_books/1169/thumbnail.jp

An Archeological Survey and Testing Program Along Six Mile Creek, Lexington County, South Carolina

An archeological survey for the proposed sewage system improvements project by the Town of Springdale located 18 archeological sites. The survey involved an on-the-ground inspection of a 50 foot wide corridor along Six Mile Creek in the Sand Hills region of central South Carolina. Eleven of the sites represent prehistoric occupation: Early and Middle Archaic, Woodland, and Mississippian periods. Nineteenth and twentieth century homesites, a quarry, and an old roadbed were recorded also. These sites are interpreted and evaluated with reference to a predictive model. Four of the sites which will be directly impacted by the proposed sewer line construction were recommended for a subsurface testing program. A determination of eligibility to the National Register of Historic Places is recommended for one of these sites, 38LX2l4, based on the results of the testing program. No additional archeological testing within the right-of-way is recommended for sites 38LX225, 38LX228, and 38LX229. However, avoidance of these sites and even other sites, which adjoin the right-of-way and thus may experience adverse impacts by construction related activities, is recommended.https://scholarcommons.sc.edu/archanth_books/1154/thumbnail.jp

An Intensive Archeological Survey and Testing of the Proposed Lower Dorchester County Wastewater Facilities Project Area Near Summerville, South Carolina

https://scholarcommons.sc.edu/archanth_books/1174/thumbnail.jp

Archeological Reconnaissance and Testing Along the Broad River, Richland County, South Carolina

https://scholarcommons.sc.edu/archanth_books/1133/thumbnail.jp

Minority-carrier mobility enhancement in p+ InGaAs lattice matched to InP

Minority electron mobilities in pf-In0.ssGac4, As have been measured with the zero field time-of-flight technique. The room-temperature (297 K) minority electron mobilities for p+-In,, 53Gac47A~ doped 0.9 and 3.1 x 10” cmm3 are found to be 2900 and 3300 cm* V-’ s-l, respectively. These are the first measurements to demonstrate enhancement in minority-carrier mobility as doping is increased for heavily doped Ines3Gae.4+s. This enhancement in mobility as doping is increased is similar to that observed in p+-GaAs, which has been attributed to reductions in plasmon and carrier-carrier scattering between minority electrons and majority holes

Including fringe fields from a nearby ferromagnet in a percolation theory of organic magnetoresistance

Random hyperfine fields are essential to mechanisms of low-field magnetoresistance in organic semiconductors. Recent experiments have shown that another type of random field fringe fields due to a nearby ferromagnet can also dramatically affect the magnetoresistance. A theoretical analysis of the effect of these fringe fields is challenging, as the fringe field magnitudes and their correlation lengths are orders of magnitude larger than that of the hyperfine couplings. We extend a recent theory of organic magnetoresistance to calculate the magnetoresistance with both hyperfine and fringe fields present. This theory describes several key features of the experimental fringe-field magnetoresistance, including the applied fields where the magnetoresistance reaches extrema, the applied field range of large magnetoresistance effects from the fringe fields, and the sign of the effect

Singlet-to-triplet interconversion using hyperfine as well as ferromagnetic fringe fields

Until recently the important role that spin-physics ('spintronics') plays in organic light-emitting devices and photovoltaic cells was not sufficiently recognized. This attitude has begun to change. We review our recent work that shows that spatially rapidly varying local magnetic fields that may be present in the organic layer dramatically affect electronic transport properties and electroluminescence efficiency. Competition between spin-dynamics due to these spatially varying fields and an applied, spatially homogeneous magnetic field leads to large magnetoresistance, even at room temperature where the thermodynamic influences of the resulting nuclear and electronic Zeeman splittings are negligible. Spatially rapidly varying local magnetic fields are naturally present in many organic materials in the form of nuclear hyperfine fields, but we will also review a second method of controlling the electrical conductivity/electroluminescence, using the spatially varying magnetic fringe fields of a magnetically unsaturated ferromagnet. Fringe-field magnetoresistance has a magnitude of several per cent and is hysteretic and anisotropic. This new method of control is sensitive to even remanent magnetic states, leading to different conductivity/electroluminescence values in the absence of an applied field. We briefly review a model based on fringe-field-induced polaronpair spin-dynamics that successfully describes several key features of the experimental fringe-field magnetoresistance and magnetoelectroluminescence

Organic magnetoelectroluminescence for room temperature transduction between magnetic and optical information

Magnetic and spin-based technologies for data storage and processing provide unique challenges for information transduction to light because of magnetic metals' optical loss, and the inefficiency and resistivity of semiconductor spin-based emitters at room temperature. Transduction between magnetic and optical information in typical organic semiconductors poses additional challenges, as the spin-orbit interaction is weak and spin injection from magnetic electrodes has been limited to low temperature and low polarization efficiency. Here we demonstrate room temperature information transduction between a magnet and an organic light-emitting diode that does not require electrical current, based on control via the magnet's remanent field of the exciton recombination process in the organic semiconductor. This demonstration is explained quantitatively within a theory of spin-dependent exciton recombination in the organic semiconductor, driven primarily by gradients in the remanent fringe fields of a few nanometre-thick magnetic film

Hysteretic control of organic conductance due to remanent magnetic fringe fields

Manipulation of the remanent (zero external magnetic field) magnetization state of a single ferromagnetic film is shown to control the room-temperature conductance of an organic semiconductor thin film deposited on top. For the organic semiconductor Alq3, the magnetic fringe fields from a multidomain remanent magnetization state of the film enhance the device conductance by several percent relative to its value for the magnetically saturated ferromagnetic film. The effect of fringe fields is insensitive to ferromagnetic film's thickness (which varies the fringe field magnitude proportionately) but sensitive to the magnetic domain's correlation length