All-optical steering of light via spatial Bloch oscillations in a gas of three-level atoms

A standing-wave control field applied to a three-level atomic medium in a planar hollow-core photonic crystal waveguide creates periodic variations of linear and nonlinear refractive indexes of the medium. This property can be used for efficient steering of light. In this work we study, both analytically and numerically, the dynamics of probe optical beams in such structures. By properly designing the spatial dependence of the nonlinearity it is possible to induce long-living Bloch oscillations of spatial gap solitons, thus providing desirable change in direction of the beam propagation without inducing appreciable diffraction. Due to the significant enhancement of the nonlinearity, such self-focusing of the probe beam can be reached at extremely weak light intensities.Comment: 8 pages, 4 figure

Clementine Observations of the Zodiacal Light and the Dust Content of the Inner Solar System

Using the Moon to occult the Sun, the Clementine spacecraft used its navigation cameras to map the inner zodiacal light at optical wavelengths over elongations of 3-30 degrees from the Sun. This surface brightness map is then used to infer the spatial distribution of interplanetary dust over heliocentric distances of about 10 solar radii to the orbit of Venus. We also apply a simple model that attributes the zodiacal light as being due to three dust populations having distinct inclination distributions, namely, dust from asteroids and Jupiter-family comets (JFCs), dust from Halley-type comets, and an isotropic cloud of dust from Oort Cloud comets. The best-fitting scenario indicates that asteroids + JFCs are the source of about 45% of the optical dust cross-section seen in the ecliptic at 1 AU, but that at least 89% of the dust cross-section enclosed by a 1 AU radius sphere is of a cometary origin. When these results are extrapolated out to the asteroid belt, we find an upper limit on the mass of the light-reflecting asteroidal dust that is equivalent to a 12 km asteroid, and a similar extrapolation of the isotropic dust cloud out to Oort Cloud distances yields a mass equivalent to a 30 km comet, although the latter mass is uncertain by orders of magnitude.Comment: To be published in Icaru

Silicon-on ceramic process: Silicon sheet growth and device development for the large-area silicon sheet task of the low-cost solar array project

The technical feasibility of producing solar-cell-quality sheet silicon to meet the Department of Energy (DOE) 1986 overall price goal of $0.70/watt was investigated. With the silicon-on-ceramic (SOC) approach, a low-cost ceramic substrate is coated with large-grain polycrystalline silicon by unidirectional solidification of molten silicon. This effort was divided into several areas of investigation in order to most efficiently meet the goals of the program. These areas include: (1) dip-coating; (2) continuous coating designated SCIM-coating, and acronym for Silicon Coating by an Inverted Meniscus (SCIM); (3) material characterization; (4) cell fabrication and evaluation; and (5) theoretical analysis. Both coating approaches were successful in producing thin layers of large grain, solar-cell-quality silicon. The dip-coating approach was initially investigated and considerable effort was given to this technique. The SCIM technique was adopted because of its scale-up potential and its capability to produce more conventiently large areas of SOC

Silicon on ceramic process. Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

The technical and economic feasibility of producing solar-cell-quality sheet silicon was investigated. The sheets were made by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. Significant progress was made in all areas of the program

Nursing Innovation: Step to Full Practice Licensure

Background/local problem With the inception of the Affordable Care Act in 2010 the healthcare system was challenged to be efficient, effective, and patient centered. This transformation has challenged the nursing profession to work to the highest level of the nursing licensure. Nurses hold the distinction of being the largest profession working in healthcare, providing not only much of the direct patient care but also leadership. The Institute of Medicine 2010 The Future of Nursing Report called for nurses to reach for higher education and to become collaborative leaders in implementing change in the healthcare arena. Diabetes is a complex and expensive clinical problem, that requires nursing leadership to create innovations to efficiently and effectively meet patient needs. The purpose of this presentation is to provide an exemplar project that illustrates an advanced practice nurse utilizing research, theory and practice to create a quality improvement project and thus practice to the fullest extent of the nursing licensure to solve a local problem of ineffective diabetic education. Lessons learned and evidence that supports an innovative video diabetic educational program will be discussed to enable others to peruse similar work and/or similar process. Methods After observing and validating a clinical problem, related theories and research were evaluated to create an intervention aimed at improving healthcare quality. Garrand’s Matrix Method was used to guide a search of the literature. A database search resulted in 1219 articles for a preliminary review with 12 articles found to be specific to video education and diabetes. Within these articles themes were identified and a quality improvement project using the plan, do, study, act process was planned. Interventions This presentation will discuss 1) the research process including: formation of clinical questioning, PICO formulation, searching for the best evidence, and translating evidence into practice using theory and 2) evidence guiding a quality improvement project for individuals with Type II diabetes in a primary care setting. The broad focus is on utilization of technology to improve the knowledge of individuals with Type II diabetes. Conclusion/Implications This presentation will help nurses formulate clinical questions and proceed to quality improvement projects. It will highlight the leadership that is available in nursing profession and serve as an example of how nursing knowledge is generating practice improvements and thus provide an example of working at the fullest extent of the nursing license to create solutions to local problem

Dip-coating process: Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

The objective of this research program is to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. The past quarter demonstrated significant progress in several areas. Seeded growth of silicon-on-ceramic (SOC) with an EFG ribbon seed was demonstrated. Different types of mullite were successfully coated with silicon. A new method of deriving minority carrier diffusion length, L sub n from spectral response measurements was evaluated. ECOMOD cost projections were found to be in good agreement with the interim SAMIS method proposed by JPL. On the less positive side, there was a decrease in cell performance which we believe to be due to an unidentified source of impurities

Silicon-on-ceramic process: Silicon sheet growth and device development for the large-area silicon sheet task of the low-cost solar array project

The technical feasibility of producing solar cell quality sheet silicon to meet the DOE 1986 cost goal of 70 cents/watt was investigated. The silicon on ceramic approach is to coat a low cost ceramic substrate with large grain polycrystalline silicon by unidirectional solidification of molten silicon. Results and accomplishments are summarized