Combined grazing incidence RBS and TEM analysis of luminescent nano-SiGe/SiO2 multilayers.

Multilayer structures with five periods of amorphous SiGe nanoparticles/SiO2 layers with different thickness were deposited by Low Pressure Chemical Vapor Deposition and annealed to crystallize the SiGe nanoparticles. The use of grazing incidence RBS was necessary to obtain sufficient depth resolution to separate the signals arising from the individual layers only a few nm thick. The average size and areal density of the embedded SiGe nanoparticles as well as the oxide interlayer thickness were determined from the RBS spectra. Details of eventual composition changes and diffusion processes caused by the annealing processes were also studied. Transmission Electron Microscopy was used to obtain complementary information on the structural parameters of the samples in order to check the information yielded by RBS. The study revealed that annealing at 900 °C for 60 s, enough to crystallize the SiGe nanoparticles, leaves the structure unaltered if the interlayer thickness is around 15 nm or higher

Resolving long-range spatial correlations in jammed colloidal systems using photon correlation imaging

We introduce a new dynamic light scattering method, termed photon correlation imaging, which enables us to resolve the dynamics of soft matter in space and time. We demonstrate photon correlation imaging by investigating the slow dynamics of a quasi two-dimensional coarsening foam made of highly packed, deformable bubbles and a rigid gel network formed by dilute, attractive colloidal particles. We find the dynamics of both systems to be determined by intermittent rearrangement events. For the foam, the rearrangements extend over a few bubbles, but a small dynamical correlation is observed up to macroscopic length scales. For the gel, dynamical correlations extend up to the system size. These results indicate that dynamical correlations can be extremely long-ranged in jammed systems and point to the key role of mechanical properties in determining their nature.Comment: Published version (Phys. Rev. Lett. 102, 085702 (2009)) The Dynamical Activity Mapsprovided as Supplementary Online Material are also available on http://w3.lcvn.univ-montp2.fr/~lucacip/dam/movies.ht

Raw materials use by Mississippi furniture manufacturers, 1989

Mississippi\u27s furniture industry has grown rapidly in recent years and now ranks nationally in production of specific types of furniture. Furniture pmducers in the state use many types of wood and nonwood raw materials. Raw materials expenditures were almost $330 million for 92 firms that responded to a 1989 survey. The survey included upholstered and nonupholstered furniture producers as well as hardwood dimension and frame producers. Substantial amounts of these raw materials were obtained from suppliers within the state

Algorithms for Visualizing Phylogenetic Networks

We study the problem of visualizing phylogenetic networks, which are extensions of the Tree of Life in biology. We use a space filling visualization method, called DAGmaps, in order to obtain clear visualizations using limited space. In this paper, we restrict our attention to galled trees and galled networks and present linear time algorithms for visualizing them as DAGmaps.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Factors Affecting Mississippi’s NIPF Landowners’ Reforestation Decisions

Non-industrial private forest (NIPF) landowners have played an increasingly important role in the nation\u27s timber economy. Nearly 70% of the forestland in the South is owned by NIPF landowners (Powell et al., 1994). In Mississippi alone, these landowners control approximately 66% of the state\u27s forestland base (Hartsell and London, 1995). Therefore, NIPF landowners are expected to provide a large portion of the state\u27s supply of timber. However, whether they do so depends largely on how their timberlands are managed. Forest management decisions of NIPF landowners can impact future timber supply due to the magnitude of their collective ownership

Comparison Between Regenerators and Non-Regenerators in Mississippi: A Discriminant Analysis

Nonindustrial private forestland (NIPF) landowners in Mississippi who recently harvested timber were surveyed to examine their regeneration behavior. Differences between regenerators and nonregenerators were investigated by looking at the different factors affecting reforestation decisions. A discriminant analysis was used to identify factors that were useful in differentiating between regenerators and nonregenerators. Ownership size; sociodemographic characteristics such as income, education, place of residence, and age; awareness of existing government incentive/assistance programs; and participation in educational programs were significant variables in differentiating between regenerators and nonregenerators. Landowners who own larger timberlands had a higher propensity to engage in regeneration activities after harvests. This also was true for landowners who had higher income levels and educational attainment, and were younger, city resident, and white. Landowners who were aware of existing government incentive/assistance programs and those who participated in educational programs also were more likely to participate in pine regeneration. Landowners in Mississippi considered both ecological and economic reasons as highly important considerations in their decision to regenerate. The belief that the land would reforest itself to pine naturally, the high cost of reforestation, and lack of information on reforestation options were top reasons cited by landowners for their decision not to regenerate. South. J. Appl. For. 28(4):189 –19

Geodemographic approaches to identifying U.S. furniture markets

Demand for household furniture is shaped by a multitude of dynamic forces, from the global economic situation to subtle changes in consumer preferences. Correspondingly, the academic disciplines employed to identify, analyze, and predict these forces range from macroeconomics to psychology, and include demography, sociology, geography, and several applied fields. The demographic characteristics of furniture consumers has been a particularly popular area of research, primarily because of the availability of secondary data from various public · agencies. Some of this research is reviewed in a subsequent section of this report

Sub-Antarctic and High Antarctic Notothenioid Fishes: Ecology and Adaptational Biology Revealed by the ICEFISH 2004 Cruise of RVIB Nathaniel B. Palmer

The goal of the ICEFISH 2004 cruise, which was conducted on board RVIB Nathaniel B. Palmer and traversed the transitional zones linking the South Atlantic to the Southern Ocean, was to compare the evolution, ecology, adaptational biology, community structure, and population dynamics of Antarctic notothenioid fishes relative to the cool/temperate notothenioids of the sub-Antarctic. To place this work in a comprehensive ecological context, cruise participants surveyed the benthos and geology of the biogeographic provinces and island shelves on either side of the Antarctic Polar Front (or Antarctic Convergence). Genome-enabled comparison of the responses of cold-living and temperate notothenioids to heat stress confirmed the sensitivity of the former to a warming Southern Ocean. Successful implementation of the international and interdisciplinary ICEFISH research cruise provides a model for future exploration of the sub-Antarctic sectors of the Indian and Pacific Oceans

The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications

The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer aiming to detect the power spectrum of 21 cm fluctuations from neutral hydrogen from the Epoch of Reionization (EOR). Drawing on lessons from the Murchison Widefield Array (MWA) and the Precision Array for Probing the Epoch of Reionization (PAPER), HERA is a hexagonal array of large (14 m diameter) dishes with suspended dipole feeds. Not only does the dish determine overall sensitivity, it affects the observed frequency structure of foregrounds in the interferometer. This is the first of a series of four papers characterizing the frequency and angular response of the dish with simulations and measurements. We focus in this paper on the angular response (i.e., power pattern), which sets the relative weighting between sky regions of high and low delay, and thus, apparent source frequency structure. We measure the angular response at 137 MHz using the ORBCOMM beam mapping system of Neben et al. We measure a collecting area of 93 m^2 in the optimal dish/feed configuration, implying HERA-320 should detect the EOR power spectrum at z~9 with a signal-to-noise ratio of 12.7 using a foreground avoidance approach with a single season of observations, and 74.3 using a foreground subtraction approach. Lastly we study the impact of these beam measurements on the distribution of foregrounds in Fourier space.Comment: 13 pages, 9 figures. Replaced to match accepted ApJ versio