10,229 research outputs found
Trends in Charitable Giving in North Carolina and the Research Triangle 1997-2006
Provides an overview of giving by average amount, as a percentage of adjusted gross income, and among the state's top earners, compared with national trends, with a focus on Chatham, Durham, Orange, and Wake counties. Includes county-by-county data
Energetics of lipid bilayers with applications to deformations induced by inclusions
A new energy for the description of large deformations of lipid bilayers is formulated with mathematical rigor. This energy is derived by considering the smectic A liquid crystalline nature of lipid bilayers and the coupling between the deformations of the layers and their constituent lipid molecules. Analogies between smectic A liquid crystals, with an infinite number of layers, and lipid bilayers, with a finite number of layers, are further discussed. The novelty of the energy density is demonstrated by studying the large deformations of planar lipid bilayers induced by cylindrical inclusions. The results of this study are directly compared with the results obtained using May's theoretical framework [May, Eur. Biophys. J., 2000, 29, 17–28] in which small deformations are assumed. As expected, the proposed energy density predicts larger distortions of the lipid molecules and deformations of the lipid bilayers close to an inclusion
Spin structure of spin-1/2 baryon and spinless meson production amplitudes in photo and hadronic reactions
The most general spin structures of the spin-1/2 baryon and spinless meson
production operator for both photon and nucleon induced reactions are derived
from the partial-wave expansions of these reaction amplitudes. The present
method provides the coefficients multiplying each spin operator in terms of the
partial-wave matrix elements. The result should be useful in studies of these
reactions based on partial-wave analyses, especially, when spin observables are
considered.Comment: RevTex 34 pages, revised versio
Efficient Analysis for the Design Refinement of Large Multilayered Printed Reflectarrays
In this paper, we present an efficient numerical technique for the analysis of a reflectarray and its design refinement by the characterization of the “actual” influence of each radiating element when embedded in the antenna structure. The method makes use of the MLayAIM, a fast full-wave formulation suitable for the analysis of electrically large multilayered printed arrays which have one or more planar metallizations and vertical conductors. The low numerical complexity of the analysis method allows the development of a recursive procedure that, starting from the equivalent currents relevant to each cell of the reflectarray when this is immersed in the actual antenna layout, calculates the real phase-shift introduced by each radiating element and corrects its dimensions to better fit the antenna requirements
“You Have Forever Changed My Life”: The Need for Academic Rigor in Teaching Humanities in a Global Society
Teaching Humanities to an increasingly globalized, diverse and non-traditional student body needs to inculcate and develop what Kysilka has called thinking skills, to equip students to approach material and concepts that may seem challenging and unfamiliar. Educators may benefit from employing the approaches Gardner has developed in his theory of Multiple Intelligences, to maximally engage students with widely differing academic exposures and skills. Reader Response journaling allows students to explore and engage with unfamiliar texts. Twenty-first-century educators need to be prepared to assess student success less by testing content acquisition and theory repetition than by evaluating student development of analytical strengths and mastery of the skills of analytical performance
A New Approach to the Link Budget Concept for an OAM Communication Link
Following on from the increasing interest for electromagnetic waves carrying
Orbital Angular Momentum (OAM), different configurations of antenna systems
able to generate such beams have been proposed. However, in our opinion, a
traditional radiation pattern approach does not provide the right picture of an
OAM-based communication link. For this reason we propose a new general concept,
the "OAM-link pattern", which takes into account the peculiar phase structure
characterizing these waves. Focusing on OAM transmissions between antenna
arrays, we introduce a formula for the link budget evaluation which describes
the whole communication link and directly leads to a "classically shaped" main
lobe pattern for a proper rephased reception in the case of uniform circular
arrays.Comment: 4 pages, 3 figure
OAM multiple transmission using uniform circular arrays: numerical modeling and experimental verification with two digital television signals
In this work we present the outcomes of a radio-frequency OAM transmission
between two antenna arrays performed in a real-world context. The analysis is
supplemented by deep simulative investigations able to provide both a
preliminary overview of the experimental scenario and a posteriori validation
of the achieved results. As a first step, the far-field OAM communication link
is tested at various frequencies and the corresponding link budget is studied
by means of an angular scan generated by the rotation of the receiving system.
Then, on the same site, two digital television signals encoded as OAM modes
(=1 and =-1) are simultaneously transmitted at a common frequency
of 198.5 MHz with good mode insulation.Comment: 16 pages, 14 figure
Measuring Racial-Ethnic Diversity in California's Nonprofit Sector
Presents survey findings on the racial/ethnic diversity of the state's nonprofit boards, executive directors, and staff and on the characteristics of racially/ethnically diverse organizations including size, field of activity, location, and budget
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