Temporal frequency of radio emissions for the April 25, 1984 flare

The National Geophysical Data Center archives data of the solar-terrestrial environment. The USAF Radio Solar Telescope Network (RSTN) data allow performance of time series analysis to determine temporal oscillations as low as three seconds. The X13/3B flare which erupted in region 4474 (S12E43) on the 24 to 25 of April 1984, was selected. The soft X-rays, 1 to 8 A, remained above X-levels for 50 minutes and the radio emissions measured at Learmonth Solar Observatory reached a maximum of 3.15 x 10 to the 5th power SFUs at 410 MHz at 0000UT. A power spectral analysis of the fixed frequency RSTN data from Learmonth shows possible quasi-periodic fluctuations in the range two to ten seconds. Repetition rates or quasi-periodicities, in the case of the power spectral analysis, generally showed the same trends as the average solar radio flux at 245 and 8800 MHz. The quasi-periodicities at 1415 MHz showed no such trends

Environmental Control and Life Support Subsystem /EC/LSS/ for the 1975 space station

Environmental control and life support subsystem for long term, earth orbital space statio

A preliminary investigation of the Environmental Control and Life Support Subsystem (EC/LSS) for the space construction base manufacturing modules

The preliminary data of the environmental control and life support subsystem for a space construction base manufacturing module was reported. A space processing module, which is capable of performing production biological experiments, was chosen as a baseline configuration. The primary assemblies and components considered for use were humidity and temperature control, ventilation fan, cabin fan, water separator, condensate storage, overboard dumping, distribution system, contaminant monitoring, cabin sensors, and fire and smoke detection

Staging superstructures in high-TcT_c Sr/O co-doped La2−x_{2-x}Srx_xCuO4+y_{4+y}

We present high energy X-ray diffraction studies on the structural phases of an optimal high-$T_c$ superconductor La$_{2-x}$Sr$_x$CuO$_{4+y}$ tailored by co-hole-doping. This is specifically done by varying the content of two very different chemical species, Sr and O, respectively, in order to study the influence of each. A superstructure known as staging is observed in all samples, with the staging number $n$ increasing for higher Sr dopings $x$. We find that the staging phases emerge abruptly with temperature, and can be described as a second order phase transition with transition temperatures slightly depending on the Sr doping. The Sr appears to correlate the interstitial oxygen in a way that stabilises the reproducibility of the staging phase both in terms of staging period and volume fraction in a specific sample. The structural details as investigated in this letter appear to have no direct bearing on the electronic phase separation previously observed in the same samples. This provides new evidence that the electronic phase separation is determined by the overall hole concentration rather than specific Sr/O content and concommittant structural details.Comment: 8 pages, incl. 4 figure

A new approach to the inverse problem for current mapping in thin-film superconductors

A novel mathematical approach has been developed to complete the inversion of the Biot-Savart law in one- and two-dimensional cases from measurements of the perpendicular component of the magnetic field using the well-developed Magneto-Optical Imaging technique. Our approach, especially in the 2D case, is provided in great detail to allow a straightforward implementation as opposed to those found in the literature. Our new approach also refines our previous results for the 1D case [Johansen et al., Phys. Rev. B 54, 16264 (1996)], and streamlines the method developed by Jooss et al. [Physica C 299, 215 (1998)] deemed as the most accurate if compared to that of Roth et al. [J. Appl. Phys. 65, 361 (1989)]. We also verify and streamline the iterative technique, which was developed following Laviano et al. [Supercond. Sci. Technol. 16, 71 (2002)] to account for in-plane magnetic fields caused by the bending of the applied magnetic field due to the demagnetising effect. After testing on magneto-optical images of a high quality YBa2Cu3O7 superconducting thin film, we show that the procedure employed is effective

Fourier, Gauss, Fraunhofer, Porod and the Shape from Moments Problem

We show how the Fourier transform of a shape in any number of dimensions can be simplified using Gauss's law and evaluated explicitly for polygons in two dimensions, polyhedra three dimensions, etc. We also show how this combination of Fourier and Gauss can be related to numerous classical problems in physics and mathematics. Examples include Fraunhofer diffraction patterns, Porods law, Hopfs Umlaufsatz, the isoperimetric inequality and Didos problem. We also use this approach to provide an alternative derivation of Davis's extension of the Motzkin-Schoenberg formula to polygons in the complex plane.Comment: 21 pages, no figure

Nitrogen Fertilizer Use by a High Yielding No-Till Corn Crop

At the present time there is public concern about the effect which nitrogen (N) fertilizer use by farmers has on groundwater quality. This has resulted in research efforts to describe what happens to nitrogen fertilizer after it is applied to a crop. We have conducted a study for the past 3 years which enables us to make a reasonable estimate of how much fertilizer N is taken up by a high yielding corn crop. And, depending on whether the corn is harvested for silage or grain, we have estimated how much of the fertilizer N is removed from the field. Such an evaluation provides a good picture of the extent to which fertilizer N is utilized by the crop and its potential as a groundwater pollutant

Changes in Rainfall Patterns in Kentucky During the 1980\u27s

Annual rainfall patterns in Kentucky have not been average during the 1980\u27s. During this timespan there have been two droughts of statewide significance, and there has been wide variability within the state during most years. Because of this wide fluctuation, there has been some concern that rainfall patterns either are changing or have changed. In order to evaluate this concern, rainfall data from sites in western, south central, north central, east central, and eastern Kentucky were analyzed. An average amount of rainfall which would be predicted for these sites was calculated, using the average of that which fell annually from approximately 1960-1980. Average of that which fell annually from 1981-1986 was calculated to use for comparison with the long-term average to determine if rainfall during the 1980\u27s has changed from that which would have been predicted. Additionally, rainfall amounts were calculated for the periods December-March and April-November. This was done in order to determine if any changes in annual distribution of rainfall had also taken place during the 1980\u27s. The reason for selecting the period December-March is that rainfall which occurs during this period recharges groundwater and contributes greatly to streamflow throughout the year. Total rainfall averages for the 1970\u27s were also calculated as another comparison for that of the 1980\u27s