Power Switching in Hybrid Coherent Couplers

We report on a theoretical and numerical investigation of the switching of power in new hybrid models of nonlinear coherent couplers consisting of optical slab waveguides with various orders of nonlinearity. The first model consists of two guides with second-order instead of the usual third-order susceptibilities as typified by the Jensen coupler. This second-order system is shown to have a power self-trapping transition at a critical power greater than the third-order susceptibility coupler. Next, we consider a mixed coupler composed of a second-order guide coupled to a third-order guide and show that, although it does not display a rigorous self-trapping transition, for a particular choice of parameters it does show a fairly abrupt trapping of power at a lower power than in the third-order coupler. By coupling this mixed nonlinear pair to a third, purely linear guide, the power trapping can be brought to even lower levels and in this way a satisfactory switching profile can be achieved at less than one sixth the input power needed in the Jensen coupler.Comment: Latex source,17 pages, 5 figure

A Sphere-Scanning Radiometer for Rapid Directional Measurements of Sky and Ground Radiance: the PARABOLA Field Instrument

A unique field instrument, called the PARABOLA, a collapsable support boom, which is self contained and easily transportable to remote sites to enable the acquisition of radiance data for almost the complete (4 pi) sky and ground-looking hemispheres in only 11 seconds was designed. The PARABOLA samples in 15 deg instantaneous field of view sectors in three narrow bandpass spectral channels simultaneously. Field measurement on a variety of earth surface cover types using a truck boom, a specially designed pickup truck mounting system, and a hot air balloon were studied. The PARABOLA instrument has potential for climatological and other studies which require characterization of the distribution of diffuse solar radiation within the sky hemisphere

Using LANDSAT digital data for estimating green biomass

The author has identified the following significant results. Relationships between the quantity of mixed prairie rangeland vegetation and LANDSAT MSS response were studied during four growing seasons at test sites throughout the United States Great Plans region. A LANDSAT derived parameter, the normalized difference was developed from theoretical considerations fro statistical estimation of the amount and seasonal condition of rangeland vegetation. This parameter was tested for application to local assessment of green forage biomass and regional monitoring of range feed conditions and drought. Results show that for grasslands in the Great Plains with near continuous vegetative cover and free of heavy brush and forbs, the LANDSAT digital data can provide a useful estimate of the quantity of green forage biomass (within 250 kg/ha), and at least five levels of pasture and range feed conditions can be adequately mapped for extended regions

Fundamental remote sensing science research program. Part 1: Scene radiation and atmospheric effects characterization project

Brief articles summarizing the status of research in the scene radiation and atmospheric effect characterization (SRAEC) project are presented. Research conducted within the SRAEC program is focused on the development of empirical characterizations and mathematical process models which relate the electromagnetic energy reflected or emitted from a scene to the biophysical parameters of interest

Sharp Concentration of Hitting Size for Random Set Systems

Consider the random set system of {1,2,...,n}, where each subset in the power set is chosen independently with probability p. A set H is said to be a hitting set if it intersects each chosen set. The second moment method is used to exhibit the sharp concentration of the minimal size of H for a variety of values of p.Comment: 11 page

Excitation of plasma resonances by a small pulsed dipole

Resonant oscillation decay excited by pulsed dipole in collisionless plasm

Alien Registration- Deering, Julia (Caribou, Aroostook County)

https://digitalmaine.com/alien_docs/26175/thumbnail.jp

Neuromuscular Function in Women Postpartum

Efficient abdominal muscle function is important for functional mobility in men and women, and dysfunction of these muscles has been associated with impaired function such as low back pain. This dissertation explored abdominal muscle function in healthy young men and young women who have never been pregnant (nulligravid). As pregnancy and child birth also impact the tissues of the abdominal wall, this dissertation will also explore abdominal muscle function in postpartum women. This dissertation involved three primary aims. Aim1 compared abdominal muscle function and experimental pain perception in males and nulligravid females. Maximal strength over a range of trunk angles, force steadiness and fatigability of the trunk flexor muscles were assessed. Although the trunk flexor muscles of males were stronger than females, there were minimal differences in fatigability during an intermittent submaximal contraction. Aim 2 determined the impact of pregnancy and childbirth on trunk flexor strength and fatigability at 8-10 weeks and 24-26 weeks postpartum. To determine the impact of delivery method, trunk flexor function was also compared in women who underwent Cesarean or vaginal delivery. Postpartum women were significantly weaker and more fatigable than control women up to 26 weeks postpartum. At 8-10 weeks postpartum, women who experienced Cesarean delivery were more fatigable than women who delivered vaginally, with no difference between delivery types at 26 weeks postpartum. Finally, Aim 3 assessed a novel test of abdominal function that may be used in the clinic, and compared fatigability of the lumbopelvic stabilizing muscles and experimental pain in postpartum and nulligravid women, and across delivery types. The lumbopelvic stabilizing muscles of postpartum women were more fatigable than control women up to 26 weeks postpartum in the clinically adapted test. Postpartum women were also more sensitive to pain at the abdomen than control women at 8 weeks and 26 weeks after childbirth. Thus, women had impaired abdominal function and increased pain at least 6 months after childbirth, with greater initial decrements in function after Cesarean delivery compared with vaginal delivery. These findings highlight the importance of assessment and rehabilitation of the abdominal muscles after pregnancy