Energy localisation and frequency analysis in the locust ear

Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami like fashion, resulting in energy localisation that focuses vibrations onto the mechanosensory neurons in a frequency dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localisation. <br/

A Predictive Model for Convective Flows Induced by Surface Reactivity Contrast

Concentration gradients in a fluid along a reactive surface due to contrast in surface reactivity generate convective flows. These flows result from contributions by electro and diffusio osmotic phenomena. In this study we have analyzed reactive patterns that release and consume protons, analogous to bimetallic catalytic conversion of peroxide. Here, we present a simple analytical model that accurately predicts the induced potentials and consequent velocities in such systems over a wide range of input parameters. Our model is tested against direct numerical solutions to the coupled Poisson, Nernst-Planck, and Navier-Stokes equations. Our analysis can be used to predict enhancement of mass transport and the resulting impact on overall catalytic conversion, and is also applicable to predicting the speed of catalytic nanomotors

Evaluating the Potential Effects of Deicing Salts on Roadside Carbon Sequestration

This project sought to document patterns of road deicing salts and the effects of these salts on the amount of carbon being sequestered passively along Montana Department of Transportation roads; it was designed collaboratively with a related roadside project that tested three different highway right-of-way management techniques (mowing height, shrub planting, disturbance) to determine whether they have the capacity to increase soil organic carbon. Our sampling did not reveal elevated salt levels at any of the nine locations sampled at each of the three I-90 sites. The greatest saline concentrations were found at the sample locations farthest from the road. This pattern was consistent across all three sites. The range of soil organic matter (SOM) was broad, from ~1% to >10%. Generally, SOM values were lowest adjacent to the road and highest farthest from the road. We found no or weak evidence of a relationship between our indices of soil salinity and SOM levels, with electrical conductivity, exchangeable calcium, and cation exchange capacity. Results imply that if road deicing salts are altering patterns of roadside SOM and potential carbon sequestration, this effect was not captured by our experimental design, nor did deicing salts appear to have affected roadside vegetation during our most recent sampling effort. Our findings highlight the value of experimentally separating the multiple potentially confounding effects of winter maintenance operations on roadside soils: roads could focus the flow of water, salts, and sands to roadside soils. How these types of mass inputs to roadside soils might influence medium- or long-term carbon dynamics remains an open question, but their fuller characterization and possible flow paths will be essential to clarifying the role of roadside soils in terrestrial soil organic carbon sequestration strategies

Beneath the Baselines: Detecting Molecular Emission from Submillimeter Galaxies with the GBT

We report the first detection of a submillimeter galaxy (SMG) in CO(1 →0) emission using the GBT. We identify a line with Δv_(FWHM) ~1000 kms^(−1) in the 1 cm spectrum of SMM J13120+4242 at z = 3.408, which is significantly greater than the width of the previously detected CO(4→3) line. If the observed CO(1→0) line profile arises from a single object and not several merging objects, the CO(4 →3)/CO(1→0) brightness temperature ratio of ~0.26 suggests n(H_2) > 10^3 cm^(−3) and the presence of sub-thermally excited gas. The 10σ integrated line flux implies a cold molecular gas mass M(H2) ~10^(11)M_⊙, comparable to the dynamical mass estimate and four times larger than the H_2 mass found from the CO(4 →3) line. While our observations confirm that this SMG is massive and highly gas-rich, they also suggest that J_(upper) > 3 transitions of CO may not accurately trace cold, diffuse molecular gas in SMGs

A trajectory approach to two-state kinetics of single particles on sculpted energy landscapes

We study the trajectories of a single colloidal particle as it hops between two energy wells A and B, which are sculpted using adjacent optical traps by controlling their respective power levels and separation. Whereas the dynamical behaviors of such systems are often treated by master-equation methods that focus on particles as actors, we analyze them here instead using a trajectory-based variational method called Maximum Caliber, which utilizes a dynamical partition function. We show that the Caliber strategy accurately predicts the full dynamics that we observe in the experiments: from the observed averages, it predicts second and third moments and covariances, with no free parameters. The covariances are the dynamical equivalents of Maxwell-like equilibrium reciprocal relations and Onsager-like dynamical relations. In short, this work describes an experimental model system for exploring full trajectory distributions in one-particle two-state systems, and it validates the Caliber approach as a useful way to understand trajectory-based dynamical distribution functions in this system.Comment: 4 pages, 4 figures, submitted to Physical Review Letter

Snow Cover in Alaska: Comprehensive Review

This report presents the results of a statistical analysis of snow cover in Alaska using historical data acquired from the Global Historical Climate Network. Measurements of snow depth and snow water equivalence were collected for Alaska stations between 1950 and 2017. Data cleaning and a distribution analysis were completed for all stations. Finally regression equations were developed to estimate snow water equivalence using recorded snow depth data from Alaska stations. The project is partially supported by ConocoPhillips Arctic Science and Engineering Foundation, UAA, and the Structural Engineers Association of Alaska (SEAAK).University of Alaska Anchorage ConocoPhillips Arctic Science and Engineering Foundation Structural Engineers Association of AlaskaAbstract / Introduction / Methodology / Discussion / Conclusion / References / Appendix 1 Predicted 50-year WESD Stations's snow laods / Appendix 2 Calcuated 50-Year SNWD Station's snow loads / Appendix 3 Distribution Assignment for WESD and SNWD Stations / Appendix 4 Station Plot

The design of a common lunar lander

The Austin Cynthesis Corporation was formed to respond to a Request for Proposal for the design of a Common Lunar Lander (CLL) capable of carrying lightweight (less than 500 kg), unspecified payload to the moon. This Final Design Report Document includes information on the requirements for the design project; the ideas proposed as solutions to the design problem; the work which has been completed in support of the design effort; justifications, validations, and verifications of decisions made during the project; and suggestions for future work to be done in support of the project. A project schedule, including current status of the items included on the schedule, as well as cost and management summaries is also included

GOES-R Algorithms: A Common Science and Engineering Design and Development Approach for Delivering Next Generation Environmental Data Products

GOES-R, the next generation of the National Oceanic and Atmospheric Administration’s (NOAA) Geostationary Operational Environmental Satellite (GOES) System, represents a new technological era in operational geostationary environmental satellite systems. GOES-R will provide advanced products that describe the state of the atmosphere, land, oceans, and solar/ space environments over the western hemisphere. The Harris GOES-R Ground Segment team will provide the software, based on government-supplied algorithms, and engineering infrastructures designed to produce and distribute these next-generation data products. The Harris GOES-R Team has adopted an integrated applied science and engineering approach that combines rigorous system engineering methods, with modern software design elements to facilitate the transition of algorithms for Level 1 and 2+ products to operational software. The Harris Team GOES-R GS algorithm framework, which includes a common data model interface, provides general design principles and standardized methods for developing general algorithm services, interfacing to external data, generating intermediate and L1b and L2 products and implementing common algorithm features such as metadata generation and error handling. This work presents the suite of GOES-R products, their properties and the process by which the related requirements are maintained during the complete design/development life-cycle. It also describes the algorithm architecture/engineering approach that will be used to deploy these algorithms, and provides a preliminary implementation road map for the development of the GOES-R GS software infrastructure, and a view into the integration of the framework and data model into the final design