Monopropellant combustion system

An apparatus and method are provided for decomposition of a propellant. The propellant includes an ionic salt and an additional fuel. Means are provided for decomposing a major portion of the ionic salt. Means are provided for combusting the additional fuel and decomposition products of the ionic salt

Simulation Studies of Nanomagnet-Based Architecture

We report a simulation study on interacting ensembles of Co nanomagnets that can perform basic logic operations and propagate logic signals, where the state variable is the magnetization direction. Dipole field coupling between individual nanomagnets drives the logic functionality of the ensemble and coordinated arrangements of the nanomagnets allow for the logic signal to propagate in a predictable way. Problems with the integrity of the logic signal arising from instabilities in the constituent magnetizations are solved by introducing a biaxial anisotropy term to the Gibbs magnetic free energy of each nanomagnet. The enhanced stability allows for more complex components of a logic architecture capable of random combinatorial logic, including horizontal wires, vertical wires, junctions, fanout nodes, and a novel universal logic gate. Our simulations define the focus of scaling trends in nanomagnet-based logic and provide estimates of the energy dissipation and time per nanomagnet reversal

Shuttle-launch triangular space station

A triangular space station deployable in orbit is described. The framework is comprized of three trusses, formed of a pair of generally planar faces consistine of foldable struts. The struts expand and lock into rigid structural engagement forming a repetition of equilater triangles and nonfolding diagonal struts interconnecting the two faces. The struts are joined together by node fittings. The framework can be packaged into a size and configuration transportable by a space shuttle. When deployed, the framework provides a large work/construction area and ample planar surface area for solar panels and thermal radiators. A plurity of modules are secured to the framework and then joined by tunnels to make an interconnected modular display. Thruster units for the space station orientation and altitude maintenance are provided

An Atmospheric Hydraulic Jump in the Santa Barbara Channel

As part of the Precision Atmospheric Marine Boundary Layer Experiment, the University of Wyoming King Air sampled an atmospheric environment conducive to the formation of a hydraulic jump on 24 May 2012 off the coast of California. Strong, northwesterly flow rounded the Point Arguello–Point Conception complex and encountered the remnants of an eddy circulation in the Santa Barbara Channel. The aircraft flew an east–west vertical sawtooth pattern that captured a sharp thinning of the marine boundary layer and the downstream development of a hydraulic jump. In situ observations show a dramatic rise in isentropes and a coincident sudden decrease in wind speeds. Imagery from the Wyoming Cloud Lidar clearly depicts the jump feature via copolarization and depolarization returns. Estimations of MBL depth are used to calculate the upstream Froude number from hydraulic theory. Simulations using the Weather Research and Forecasting Model produced results in agreement with the observations. The innermost domain uses a 900-m horizontal grid spacing and encompasses the transition from supercritical to subcritical flow south of Point Conception. Upstream Froude number estimations from the model compare well to observations. A strongly divergent wind field, consistent with expansion fan dynamics, is present upwind of the hydraulic jump. The model accurately resolves details of the marine boundary layer collapse into the jump. Results from large-eddy simulations show a large increase in the turbulent kinetic energy field coincident with the hydraulic jump

Ready, Set, Communicate: Measuring Usability of Instructional Modules Designed to Improve Communications Skills of Students Studying Agricultural Sciences

Well-developed communications skills are essential to a proficient agricultural workforce. Online instruction via reusable learning modules (RLMs) is one way agricultural science faculty can provide their students with expert communications skills training. Although RLMs have many benefits, their value degrades rapidly if the learner cannot access or use the technology efficiently. Therefore, online instruction must be tested to ensure usability. The purpose of our study was to assess the usability of RLMs developed to bolster the communications skills of students studying in the agricultural sciences and provide guidance for future curricula and online instruction development. We used quantitative and qualitative data sources to assess the usability of three RLMs, according to N = 21 students. The usability metrics we assessed included learnability, navigation, video function, document access and readability, quiz and assignment practicality, and task difficulty. The RLMs garnered high usability scores from participants who had positive impressions and experiences completing them. Participants demonstrated an increase in confidence to perform communications skills and an increase in knowledge about communications after completing the modules. They thought embedded videos, documents, quizzes, and assignments were helpful in learning communications concepts. Some recommended improving navigation, document readability, and assignment details. Based on our findings, we recommend RLM developers embed short videos, printable handouts, and quizzes into RLMs, and include an overview of documents’ key points to guide reading. Participants’ positive feedback and willingness to engage with the RLMs suggests incorporating the RLMs into agricultural science courses will help students develop into science communicators

Effect of vessel wettability on the foamability of "ideal" surfactants and "real-world" beer heads

The ability to tailor the foaming properties of a solution by controlling its chemical composition is highly desirable and has been the subject of extensive research driven by a range of applications. However, the control of foams by varying the wettability of the foaming vessel has been less widely reported. This work investigates the effect of the wettability of the side walls of vessels used for the in situ generation of foam by shaking aqueous solutions of three different types of model surfactant systems (non-ionic, anionic and cationic surfactants) along with four different beers (Guinness Original, Banks’s Bitter, Bass No 1 and Harvest Pale). We found that hydrophilic vials increased the foamability only for the three model systems but increased foam stability for all foams except the model cationic system. We then compared stability of beer foams produced by shaking and pouring and demonstrated weak qualitative agreement between both foam methods. We also showed how wettability of the glass controls bubble nucleation for beers and champagne and used this effect to control exactly where bubbles form using simple wettability patterns

Lead Bullet Fragments in Venison from Rifle-Killed Deer: Potential for Human Dietary Exposure

Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15–409) and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80%) of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 µg/dL (maximum 3.8 µg/dL) 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 µg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low-income beneficiaries of venison donations

Ultra-cold Polarized Fermi Gases

Recent experiments with ultra-cold atoms have demonstrated the possibility of realizing experimentally fermionic superfluids with imbalanced spin populations. We discuss how these developments have shed a new light on a half- century old open problem in condensed matter physics, and raised new interrogations of their own.Comment: 27 pages; 8 figures; Published in Report in Rep. Prog. Phys. 73 112401 (2010