Parametrization of the Driven Betatron Oscillation

An AC dipole is a magnet which produces a sinusoidally oscillating dipole field and excites coherent transverse beam motion in a synchrotron. By observing this coherent motion, the optical parameters can be directly measured at the beam position monitor locations. The driven oscillation induced by an AC dipole will generate a phase space ellipse which differs from that of the free oscillation. If not properly accounted for, this difference can lead to a misinterpretation of the actual optical parameters, for instance, of 6% or more in the cases of the Tevatron, RHIC, or LHC. The effect of an AC dipole on the linear optics parameters is identical to that of a thin lens quadrupole. By introducing a new amplitude function to describe this new phase space ellipse, the motion produced by an AC dipole becomes easier to interpret. Beam position data taken under the influence of an AC dipole, with this new interpretation in mind, can lead to more precise measurements of the normal Courant-Snyder parameters. This new parameterization of the driven motion is presented and is used to interpret data taken in the FNAL Tevatron using an AC dipole.Comment: 8 pages, 8 figures, and 1 tabl

Cluster Analysis as a Tool of Interpretation of Complex Systems

This paper deals with several problems in cluster analysis. It appears that the suggested solutions have not been considered in current literature. First, the author proposes the use of a permuted matrix as a tool for interpretation of clusters generated by hierarchical agglomerative clustering algorithms. Second, a new method of defining similarity between a pair of clusters is shown. This method leads to a new class of hierarchical agglomerative clustering. Third, two criteria are defined to optimize dendrograms that are outputs of hierarchical clustering. This paper has been presented at the Task Force Seminar Session on New Advances in Decision Support Systems, Laxenburg, Austria, November 3-5, 1986

Water Infiltration and Permeability of Selected Urban Soils as Affected by Salinity and Sodicity

Soil sodicity is known to affect soil structural stability and permeability. However, the impact differs depending on salinity of irrigation water, soil types as well as irrigation management practices. This study examined water infiltration into two alluvial soils (Torrifluvents), and two upland soils (Paleorthid and Calciorthid, Aridisols) placed in greenhouse pots. For the first experiment, irrigation solutions simulating the Rio Grande water, city potable water, and two sources of reclaimed water (EC of 1.4 and 2.2 dS m-1 and SAR of 6 and 11) were applied twice a week at 1.7 cm per application for a total of 27 irrigation events using 46 cm of water. No significant effect of water quality was detected in Delnorte gravelly loam (Paleorthid) and a small effect on infiltration into Harkey silt loam (Torrifluvent). However, the use of distilled water curtailed infiltration mainly in Harkey soil. In the second greenhouse experiment using a carefully crafted soil packing and water application protocols, the impact of water quality on infiltration into two Torrifluvents, Harkey silt loam and Glendale silty clay loam appeared after water application of 40 to 50 cm (16" - 20"). When saline solutions were applied as deep as 10 cm per application, the infiltration time nearly doubled when SAR of the solution increased from 1 to 6 or 12 in alluvial soils, but not in Turney silty clay loam (Calciorthid, Aridisol). When the irrigation depth per application was reduced to 7.5, 5.0, and 2.5 cm per application, the difference in infiltration rate was markedly reduced. The impact of elevated sodicity (SAR of 6 to 12) on infiltration can be an issue in alluvial soils, but unlikely in upland soils at irrigation water salinity of 1 to 2 dS m-1

Salinization of Irrigated Urban Soils: A Case Study of El Paso, TX

This study was conducted to assess soil salinity levels in large landscape areas, such as golf courses, parks, and school grounds which were developed on various soil types in El Paso, Texas. The survey encompassed the East, the Central, the Northwest, and the Upper and Lower Valleys, covering 16 fairways at seven golf courses, 37 city parks, 30 school grounds, and 13 apartment landscapes on the Westside. The highest soil salinity (6 to 11 dS m-1) was found in the clayey soils of the Upper and Lower valleys, even when water of low salinity (650 to 750 ppm) had been used for irrigation. Spadoratic soil salinization was also observed in loamy soils of the South Central irrigated with city potable water, and topdressed soils of the Northwest after conversion to reclaimed water. Soil salinization was not observed in deep sand along I-10, and seldom in sandy calcic soils in the East and North Central, even though these soils contain a layer of caliche. Soil types play a role on soil salinization as much as does water quality

Key Requirements for Successful Use of Moderately Saline Water for Landscape Irrigation: Southwestern Experience

The primary objective of using moderately saline water for irrigation, including reclaimed municipal effluent, is to conserve potable water, and its impact on quality of landscapes or the costs of landscape maintenance have received lesser attention. The experience in the Southwest indicates that when salinity of irrigation water is less than approximately 750 ppm or sodium (Na) and Chloride (Cl) concentrations are less than 150 mg L-1, landscape degradation caused by salts is minimal, except in areas with poorly permeable soils. When salinity or Na and Cl concentrations exceed these threshold values, however, salt-induced landscape degradation has been more frequent and intense than previously thought. This presentation outlines the types of problems encountered, and the key requirements for improving reuse practices based on the experiences in west Texas and southern New Mexico where water of elevated salinity (up to 3000 ppm) is used for irrigation

B-mode polarization induced by gravitational waves from kinks on infinite cosmic strings

We investigate the effect of the stochastic gravitational wave (GW) background produced by kinks on infinite cosmic strings, whose spectrum was derived in our previous work, on the B-mode power spectrum of the cosmic microwave background (CMB) anisotropy. We find that the B-mode polarization due to kinks is comparable to that induced by the motion of the string network and hence the contribution of GWs from kinks is important for estimating the B-mode power spectrum originating from cosmic strings. If the tension of cosmic strings \mu is large enough i.e., G\mu >~ 10^{-8}, B-mode polarization induced by cosmic strings can be detected by future CMB experiments.Comment: 13 pages, 1 figur

Gravitational waves from kinks on infinite cosmic strings

Gravitational waves emitted by kinks on infinite strings are investigated using detailed estimations of the kink distribution on infinite strings. We find that gravitational waves from kinks can be detected by future pulsar timing experiments such as SKA for an appropriate value of the the string tension, if the typical size of string loops is much smaller than the horizon at their formation. Moreover, the gravitational wave spectrum depends on the thermal history of the Universe and hence it can be used as a probe into the early evolution of the Universe.Comment: 29 pages, 4figure

Group velocity and causality in standard relativistic resistive magnetohydrodynamics

Group velocity of electromagnetic waves in plasmas derived by standard relativistic resistive MHD (resistive RMHD) equations is superluminal. If we assume that the group velocity represents the propagation velocity of a signal, we have to worry about the causality problem. That is, some acausal phenomena may be induced, such that information transportation to the absolute past and spontaneous decrease in the entropy. Here, we tried to find the acausal phenomena using standard resistive RMHD numerical simulations in the suggested situation of the acausal phenomena. The calculation results showed that even in such situations no acausal effect happens. The numerical result with respect to the velocity limit of the information transportation is consistent with a linear theory of wave train propagation. Our results assure that we can use these equations without problems of acausal phenomena.Comment: 28 pages, 10 figure