10,762 research outputs found
Designing of metallic photonic structures and applications
In this thesis our main interest has been to investigate metallic photonic crystal and its applications. We explained how to solve a periodic photonic structure with transfer matrix method and when and how to use modal expansion method. Two different coating methods were introduced, modifying a photonic structure\u27s intrinsic optical properties and rigorous calculation results are presented;Two applications of metallic photonic structures are introduced. For thermal emitter, we showed how to design and find optimal structure. For conversion efficiency increasing filter, we calculated its efficiency and the way to design it
Rich variety of defects in ZnO via an attractive interaction between O-vacancies and Zn-interstitials
As the concentration of intrinsic defects becomes sufficiently high in
O-deficient ZnO, interactions between defects lead to a significant reduction
in their formation energies. We show that the formation of both O-vacancies and
Zn-interstitials becomes significantly enhanced by a strong attractive
interaction between them, making these defects an important source of n-type
conductivity in ZnO.Comment: 12 pages, 4 figure
Stretching-induced conductance variations as fingerprints of contact configurations in single-molecule junctions
Molecule-electrode contact atomic structures are a critical factor that
characterizes molecular devices, but their precise understanding and control
still remain elusive. Based on combined first-principles calculations and
single-molecule break junction experiments, we herein establish that the
conductance of alkanedithiolate junctions can both increase and decrease with
mechanical stretching and the specific trend is determined by the S-Au linkage
coordination number (CN) or the molecule-electrode contact atomic structure.
Specifically, we find that the mechanical pulling results in the conductance
increase for the junctions based on S-Au CN two and CN three contacts, while
the conductance is minimally affected by stretching for junctions with the CN
one contact and decreases upon the formation of Au monoatomic chains. Detailed
analysis unravels the mechanisms involving the competition between the
stretching-induced upshift of the highest occupied molecular orbital-related
states toward the Fermi level of electrodes and the deterioration of
molecule-electrode electronic couplings in different contact CN cases.
Moreover, we experimentally find a higher chance to observe the conductance
enhancement mode under a faster elongation speed, which is explained by ab
initio molecular dynamics simulations that reveal an important role of thermal
fluctuations in aiding deformations of contacts into low-coordination
configurations that include monoatomic Au chains. Pointing out the
insufficiency in previous notions of associating peak values in conductance
histograms with specific contact atomic structures, this work resolves the
controversy on the origins of ubiquitous multiple conductance peaks in
S-Au-based single-molecule junctions.Comment: 11 pages, 4 figures; to be published in J. Am. Chem. So
THE COMMERCIAL POTENTIAL OF NEW DAIRY PRODUCTS FROM MEMBRANE TECHNOLOGY
Membrane filtration technologies are capable of creating entirely new, more functional food products. In this regard, potential new dairy products include high-protein, low-lactose fluid milk, high-protein, low-lactose ice cream, and non-far yogurt made with fewer stabilizers. An initial survey of membrane manufacturing companies determined the added cost to produce such functional food products to be two to six percent of the existing retail price for similar standard dairy products. A subsequent survey of milk processors found that the most likely adopters of such membrane technologies were yogurt manufacturers.Agribusiness,
A gene sets approach for identifying prognostic gene signatures for outcome prediction
<p>Abstract</p> <p>Background</p> <p>Gene expression profiling is a promising approach to better estimate patient prognosis; however, there are still unresolved problems, including little overlap among similarly developed gene sets and poor performance of a developed gene set in other datasets.</p> <p>Results</p> <p>We applied a gene sets approach to develop a prognostic gene set from multiple gene expression datasets. By analyzing 12 independent breast cancer gene expression datasets comprising 1,756 tissues with 2,411 pre-defined gene sets including gene ontology categories and pathways, we found many gene sets that were prognostic in most of the analyzed datasets. Those prognostic gene sets were related to biological processes such as cell cycle and proliferation and had additional prognostic values over conventional clinical parameters such as tumor grade, lymph node status, estrogen receptor (ER) status, and tumor size. We then estimated the prediction accuracy of each gene set by performing external validation using six large datasets and identified a gene set with an average prediction accuracy of 67.55%.</p> <p>Conclusion</p> <p>A gene sets approach is an effective method to develop prognostic gene sets to predict patient outcome and to understand the underlying biology of the developed gene set. Using the gene sets approach we identified many prognostic gene sets in breast cancer.</p
Two-dimensional heterogeneous photonic bandedge laser
We proposed and realized a two-dimensional (2D) photonic bandedge laser
surrounded by the photonic bandgap. The heterogeneous photonic crystal
structure consists of two triangular lattices of the same lattice constant with
different air hole radii. The photonic crystal laser was realized by
room-temperature optical pumping of air-bridge slabs of InGaAsP quantum wells
emitting at 1.55 micrometer. The lasing mode was identified from its spectral
positions and polarization directions. A low threshold incident pump power of
0.24mW was achieved. The measured characteristics of the photonic crystal
lasers closely agree with the results of real space and Fourier space
calculations based on the finite-difference time-domain method.Comment: 14 pages, 4 figure
THE EFFECT OF NEW FOOD LABELING ON NUTRIENT INTAKES: AN ENDOGENOUS SWITCHING REGRESSION ANALYSIS
This paper examines the effect of the new labeling regulations on nutrient intakes using an endogenous switching regression model. Using the 1994 - 96 CSFII/DHKS, we evaluate the impact of food label use on intakes of selected nutrients.Food Consumption/Nutrition/Food Safety,
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