Endless tape cartridge Patent

Tape cartridge with high capacity storage of endless-loop magnetic tap

Kinetic step bunching during surface growth

We study the step bunching kinetic instability in a growing crystal surface characterized by anisotropic diffusion. The instability is due to the interplay between the elastic interactions and the alternation of step parameters. This instability is predicted to occur on a vicinal semiconductor surface Si(001) or Ge(001) during epitaxial growth. The maximal growth rate of the step bunching increases like $F^{4}$, where $F$ is the deposition flux. Our results are complemented with numerical simulations which reveals a coarsening behavior on the long time for the nonlinear step dynamics.Comment: 4 pages, 6 figures, submitted to PR

The Variable-Rate Decision for Multiple Inputs with Multiple Management Zones

Research has evaluated the relative profitability of variable-rate versus uniform-rate application of a single input in fields with multiple management zones. This paper addresses the variable-rate decision for multiple inputs. The decision-making framework is evaluated for nitrogen and water applied to irrigated cotton in fields with three management zones.Crop Production/Industries,

Effect of step stiffness and diffusion anisotropy on the meandering of a growing vicinal surface

We study the step meandering instability on a surface characterized by the alternation of terraces with different properties, as in the case of Si(001). The interplay between diffusion anisotropy and step stiffness induces a finite wavelength instability corresponding to a meandering mode. The instability sets in beyond a threshold value which depends on the relative magnitudes of the destabilizing flux and the stabilizing stiffness difference. The meander dynamics is governed by the conserved Kuramoto-Sivashinsky equation, which display spatiotemporal coarsening.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Lett. (February 2006

The Variable-Rate Input Application Decision for Multiple Inputs with Interactions

Research has evaluated the relative profitability of variable-rate (VRT) versus uniform-rate (URT) application of a single input in fields with multiple management zones. This study addresses map-based VRT decisions for multiple inputs in fields with multiple management zones. The decision-making framework is illustrated for nitrogen and water applied to irrigated cotton in fields with three management zones. Results suggest traditional methods of determining VRT application of a single input may by suboptimal if interactions exist among VRT inputs and URT inputs. Implications are that a systems approach to multiple-input VRT decisions can produce increased net returns to VRT.breakeven analysis, cotton, economic feasibility, multiple-inputs, precision farming, variable-rate technology, Crop Production/Industries,

Investigation of a pulsed electrothermal thruster system

The performance of an ablative wall Pulsed Electrothermal (PET) thruster is accurately characterized on a calibrated thrust stand, using polyethylene propellant. The thruster is tested for four configurations of capillary length and pulse length. The exhaust velocity is determined with twin time-of-flight photodiode stagnation probes, and the ablated mass is measured from the loss over ten shots. Based on the measured thrust impulse and the ablated mass, the specific impulse varies from 1000 to 1750 seconds. The thrust to power varies from .05 N/kW (quasi-steady mode) to .10 N/kW (unsteady mode). The thruster efficiency varies from .56 at 1000 seconds to .42 at 1750 seconds. A conceptual design is presented for a 40 kW PET propulsion system. The point design system performance is .62 system efficiency at 1000 seconds specific impulse. The system's reliability is enhanced by incorporating 20, 20 kW thruster modules which are fired in pairs. The thruster design is non-ablative, and uses water propellant, from a central storage tank, injected through the cathode

Statistics of Ku-band microwave response of the United States with a satellite borne radiometer/scatterometer

The author has identified the following significant results. The Skylab S-193 radiometer/scatterometer collected thousands of measurements of scattering coefficient and brightness temperature over various parts of the United States during the summer of 1973 at angles of incidence between vertical and about 45 deg. These measurements have been combined to produce histograms of the response at each of several angles within this range, and to establish average scattering coefficient vs angle curves with 10% and 90% exceedance levels as well. The variation of the radiometric measurements is primarily in the region from 255 K to 285 K, with very few measurements giving higher values, but a significant, though small, number giving values down to and even below 200 K. The scattering coefficient varies, for the mean, from about 0 db at 1 deg off vertical to a low in the neighborhood of -10 db at 45 deg. The variability of the scattering coefficient measurements with this coarse resolution sensor is surprisingly small. The number of distinguishable levels is slightly more for the scatterometer than for the radiometer, but the amount of variation in brightness temperature caused by the physical temperature of the ground is enough so that the scatterometer can be used to distinguish significantly more meaningful levels than the radiometer

Adoption of Conservation-Tillage Methods and Genetically Modified Cotton

Adoption of herbicide-tolerant cotton and conservation tillage may be simultaneously related. Bayes' theorem and a two-equation logit model were used to test the simultaneity hypothesis. Evidence for Tennessee suggests that adoption of these technologies reduced residual herbicide use and soil erosion more than if adoption of these technologies were independent.Bayes' theorem, conservation tillage, cotton, genetically modified crops, herbicide tolerant crops, simultaneous logit model, technology adoption, Crop Production/Industries, Q12, Q16, Q24, O33,

Adoption of No-Tillage Practices, Other Conservation-Tillage Practices and Herbicide-Resistant Cotton Seed, and Their Synergistic Environmental Impacts

If adoption of herbicide-resistant seed and adoption of conservation-tillage practices are determined simultaneously, adoption of herbicide-resistant seed could indirectly reduce soil erosion and adoption of conservation-tillage practices could indirectly reduce residual herbicide use and increase farm profits. Our objective was to evaluate the relationship between these technologies for Tennessee cotton production. Evidence from simultaneous estimation of a trinomial logit model for adoption of no-tillage, other conservation-tillage, and conventional-tillage practices and a binomial logit model for adoption of herbicide-resistant and conventional cotton seed suggests a simultaneous relationship. The elasticity for acreage in herbicide-resistant seed with respect to the probability of adopting conservation-tillage practices was 3.98. The elasticities for acreages in no-tillage practices and other conservation-tillage practices with respect to the probability of adopting herbicide-resistant cotton seed were 0.34 and 0.10, respectively. Adoption of herbicide-resistant cotton seed in Tennessee reduced soil erosion by 9.2 million tons through its effects on adoption of conservation-tillage practices. By 2004, increases in adoption of conservation-tillage practices increased adoption of herbicide-resistant cotton seed by 445 thousand acres, substituting non-residual herbicides for residual herbicides on those cotton acres.Environmental Economics and Policy,