8,892 research outputs found
Development, simulation validation, and wind tunnel testing of a digital controller system for flutter suppression
Flutter suppression (FS) is one of the active control concepts being investigated by the AFW program. The design goal for FS control laws was to increase the passive flutter dynamic pressure by 30 percent. In order to meet this goal, the FS control laws had to be capable of suppressing both symmetric and antisymmetric flutter instabilities simultaneously. In addition, the FS control laws had to be practical and low-order, robust and capable of real time execution within the 200 hz. sampling time. The purpose here is to present an overview of the development, simulation validation, and wind tunnel testing of a digital controller system for flutter suppression
A Comparison Between the Judicial and Administrative Routes to Enforce Intellectual Property Rights In China, 7 J. Marshall Rev. Intell. Prop. L. 529 (2008)
Over the past two decades, a sophisticated intellectual property law system has developed in support of China’s transition to economic superpower. In today’s global economy, it is crucial that international marketers understand how to navigate this new system to best protect their intellectual property rights. China allows for two distinct procedures by which intellectual property assets may be protected, one judicial and the other administrative. Each choice holds distinct advantages and disadvantages for a party seeking to enforce its rights. Making the best choice involves familiarization with the particulars of each procedure and gauging the likelihood of a successful outcome. The details of these procedures, along with their benefits and drawbacks, are surveyed here to provide a cursory understanding of intellectual property rights in China
Longitudinal patterns in an Arkansas River Valley stream: an Application of the River Continuum Concept
The River Continuum Concept (RCC) provides the framework for studying how lotic ecosystems vary from headwater streams to large rivers. The RCC was developed in streams in eastern deciduous forests of North America, but watershed characteristics and land uses differ across ecoregions, presenting unique opportunities to study how predictions of the RCC may differ across regions. Additionally, RCC predictions may vary due to the influence of fishes, but few studies have used fish taxa as a metric for evaluating predictions of the RCC. Our goal was to determine if RCC predictions for stream orders 1 through 5 were supported by primary producer, macroinvertebrate, and fish communities in Cadron Creek of the Arkansas River Valley. We sampled chlorophyll a, macroinvertebrates, and fishes at five stream reaches across a gradient of watershed size. Contrary to RCC predictions, chlorophyll a did not increase in concentration with catchment size. As the RCC predicts, fish and macroinvertebrate diversity increased with catchment size. Shredding and collecting macroinvertebrate taxa supported RCC predictions, respectively decreasing and increasing in composition as catchment area increased. Herbivorous and predaceous fish did not follow RCC predictions; however, surface-water column feeding fish were abundant at all sites as predicted. We hypothesize some predictions of the RCC were not supported in headwater reaches of this system due to regional differences in watershed characteristics and altered resource availability due to land use surrounding sampling sites
Myelin Characteristics of the Corpus Callosum in Capuchin Monkeys (\u3cem\u3eSapajus\u3c/em\u3e [\u3cem\u3eCebus\u3c/em\u3e] \u3cem\u3eapella\u3c/em\u3e) Across the Lifespan
The midsagittal area of the corpus callosum (CC) is frequently studied in relation to brain development, connectivity, and function. Here we quantify myelin characteristics from electron microscopy to understand more fully differential patterns of white matter development occurring within the CC. We subdivided midsagittal regions of the CC into: I—rostrum and genu, II—rostral body, III—anterior midbody, IV—posterior midbody, and V—isthmus and splenium. The sample represented capuchin monkeys ranging in age from 2 weeks to 35 years (Sapajus [Cebus] apella, n = 8). Measurements of myelin thickness, myelin fraction, and g-ratio were obtained in a systematic random fashion. We hypothesized there would be a period of rapid myelin growth within the CC in early development. Using a locally weighted regression analysis (LOESS), we found regional differences in myelin characteristics, with posterior regions showing more rapid increases in myelin thickness and sharper decreases in g-ratio in early development. The most anterior region showed the most sustained growth in myelin thickness. For all regions over the lifespan, myelin fraction increased, plateaued, and decreased. These results suggest differential patterns of nonlinear myelin growth occur early in development and well into adulthood in the CC of capuchin monkeys
Measurement of the ΔS=-ΔQ Amplitude from K_(e3)^0 Decay
We have measured the time distribution of the π^+e^-ν and π^-e^+ν modes from initial K^0's in a spark-chamber experiment performed at the Bevatron. From 1079 events between 0.2 and 7 K_S^0 lifetime, we find ReX=-0.069±0.036, ImX=+0.108_(-0.074)^(+0.092). This result is consistent with X=0 (relative probability = 0.25), but more than 4 standard deviations from the existing world average, +0.14 -0.13i
Embedded-Cluster Calculations in a Numeric Atomic Orbital Density-Functional Theory Framework
We integrate the all-electron electronic structure code FHI-aims into the
general ChemShell package for solid-state embedding (QM/MM) calculations. A
major undertaking in this integration is the implementation of pseudopotential
functionality into FHI-aims to describe cations at the QM/MM boundary through
effective core potentials and therewith prevent spurious overpolarization of
the electronic density. Based on numeric atomic orbital basis sets, FHI-aims
offers particularly efficient access to exact exchange and second order
perturbation theory, rendering the established QM/MM setup an ideal tool for
hybrid and double-hybrid level DFT calculations of solid systems. We illustrate
this capability by calculating the reduction potential of Fe in the
Fe-substituted ZSM-5 zeolitic framework and the reaction energy profile for
(photo-)catalytic water oxidation at TiO2(110).Comment: 12 pages, 4 figure
Random Sequential Adsorption: From Continuum to Lattice and Pre-Patterned Substrates
The random sequential adsorption (RSA) model has served as a paradigm for
diverse phenomena in physical chemistry, as well as in other areas such as
biology, ecology, and sociology. In the present work, we survey aspects of the
RSA model with emphasis on the approach to and properties of jammed states
obtained for large times in continuum deposition versus that on lattice
substrates, and on pre-patterned surfaces. The latter model has been of recent
interest in the context of efforts to use pre-patterning as a tool to improve
selfassembly in micro- and nanoscale surface structure engineering
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