Three-dimensional nuclear spin positioning using coherent radio-frequency control

Distance measurements via the dipolar interaction are fundamental to the application of nuclear magnetic resonance (NMR) to molecular structure determination, but they only provide information on the absolute distance $r$ and polar angle $\theta$ between spins. In this Letter, we present a protocol to also retrieve the azimuth angle $\phi$. Our method relies on measuring the nuclear precession phase after application of a control pulse with a calibrated external radio-frequency coil. We experimentally demonstrate three-dimensional positioning of individual carbon-13 nuclear spins in a diamond host crystal relative to the central electronic spin of a single nitrogen-vacancy center. The ability to pinpoint three-dimensional nuclear locations is central for realizing a nanoscale NMR technique that can image the structure of single molecules with atomic resolution.Comment: 5 pages, 4 figure

Habitats and Biota of the Gulf of Mexico: Before the Deepwater Horizon Oil Spill: Volume 1: Water Quality, Sediments, Sediment Contaminants, Oil and Gas Seeps, Coastal Habitats, Offshore Plankton and Benthos, and Shellfish

environmental management; marine; freshwater science

High-bandwidth microcoil for fast nuclear spin control

The active manipulation of nuclear spins with radio-frequency (RF) coils is at the heart of nuclear magnetic resonance (NMR) spectroscopy and spin-based quantum devices. Here, we present a microcoil transmitter system designed to generate strong RF pulses over a broad bandwidth, allowing for fast spin rotations on arbitrary nuclear species. Our design incorporates: (i) a planar multilayer geometry that generates a large field of 4.35 mT per unit current, (ii) a 50 Ohm transmission circuit with a broad excitation bandwidth of approximately 20 MHz, and (iii) an optimized thermal management for removal of Joule heating. Using individual 13C nuclear spins in the vicinity of a diamond nitrogen-vacancy (NV) center as a test system, we demonstrate Rabi frequencies exceeding 70 kHz and nuclear pi/2 rotations within 3.4 us. The extrapolated values for 1H spins are about 240 kHz and 1 us, respectively. Beyond enabling fast nuclear spin manipulations, our microcoil system is ideally suited for the incorporation of advanced pulse sequences into micro- and nanoscale NMR detectors operating at low (<1 T) magnetic field.Comment: 8 pages, 5 figures. Submitted to Rev. Sci. Inst

Structural risk assessment and aircraft fleet maintenance

In the present analysis, deterministic flaw growth analysis is used to project the failure distributions from inspection data. Inspection data is reported for each critical point in the aircraft. The data will indicate either a crack of a specific size or no crack. The crack length may be either less than, equal to, or greater than critical size for that location. Non-critical length cracks are projected to failure using the crack growth characteristics for that location to find the life when it will be at critical length. Greater-than-critical length cracks are projected back to determine the life at failure, that is, when it was at critical length. The same process is used as in the case of a non-critical crack except that the projection goes the other direction. These points, along with the critical length cracks are used to determine the failure distribution. To be able to use data from different aircraft to build a common failure distribution, a consistent life variable must be used. Aircraft life varies with the severity of the usage; therefore the number of flight hours for a particular aircraft must be modified by its usage factor to obtain a normalized life which can be compared with that from other aircraft

An Economic Analysis of Landfill Costs to Demonstrate the Economies of Size and Determine the Feasibility of a Community Owned Landfill in Rural Oklahoma

New regulations have impacted landfill costs and changed solid waste management solutions. Communities must now decide between continued landfill operations and long-term uncertainties associated with contracted services. Preliminary cost analysis addresses these changes and demonstrates economies of size that make regional facilities more feasible than the once popular city-owned landfillsEnvironmental Economics and Policy,

Habitats and Biota of the Gulf of Mexico: Before the Deepwater Horizon Oil Spill: Volume 1: Water Quality, Sediments, Sediment Contaminants, Oil and Gas Seeps, Coastal Habitats, Offshore Plankton and Benthos, and Shellfish

environmental management; marine; freshwater science

Clarifying and expanding the focus of Environmental Toxicology and Chemistry

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92138/1/1869_ftp.pd

Editorial

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95638/1/2035_ftp.pd

ANKLE TAPING ALTERS SHANK-REARFOOT JOINT COUPLING DURING WALKING IN PATIENTS WITH CHRONIC ANKLE INSTABILITY AND HEALTHY CONTROLS

The purpose of this study was to analyze the shank-rearfoot joint coupling with and without ankle taping in patients with and without chronic ankle instability (CAI) during walking gait. Twenty-three patients (CAI,n=12, healthy,n=11) participated. Three-dimensional kinematics were collected using a 12 camera motion capture. Fifteen strides were collected while subjects walked. A vector coding analysis was performed to assess the magnitude, direction (?) and variability (VCV) in the coupling between the shank transverse plane and rearfoot frontal plane motion. Both groups had lower magnitude of coupled motion around initial contact while taped. VCV was significantly lower throughout the gait cycle in both groups while taped. Ankle taping appears to create a rigid coupling pattern in both healthy and CAI patients and may explain its role in prophylactically prevention of lateral ankle sprains

Method and apparatus for eliminating unsuccessful tries in a search tree

A circuit switching system in an M-ary, n-cube connected network completes a best-first path from an originating node to a destination node by latching valid legs of the path as the path is being sought out. Each network node is provided with a routing hyperswitch sub-network, (HSN) connected between that node and bidirectional high capacity communication channels of the n-cube network. The sub-networks are all controlled by routing algorithms which respond to message identification headings (headers) on messages to be routed along one or more routing legs. The header includes information embedded therein which is interpreted by each sub-network to route and historically update the header. A logic circuit, available at every node, implements the algorithm and automatically forwards or back-tracks the header in the network legs of various paths until a completed path is latched