Special Coverage

Home

Enhancing MRI Contrast by Geometrical Confinement of Small Imaging Agents Within Nanoporous Particles

Lyndon B. Johnson Space Center, Houston, Texas Magnetic resonance imaging (MRI) has evolved into one of the most powerful, non-invasive diagnostic imaging techniques in medicine and biomedical research. The superior resolution and in-depth anatomical details provided by MRI are essential for early diagnosis of many diseases. Chemical contrast agents (CAs) have been widely used for improving the sensitivity and diagnostic confidence in MRI.

Posted in: Briefs

Read More >>

NASA Flywheel for iPad

John H. Glenn Research Center, Cleveland, Ohio NASA Flywheel is an augmented reality application intended to highlight NASA Glenn’s research efforts in the area of flywheel energy storage systems. The app utilizes a printed optical target, available on the GRC Flywheel Program brochure and through the NASA Glenn Web portal, to present users with 3D views of flywheel hardware and space applications. Additional video and imagery are also included in the application package. The software has been compiled and bundled as an iOS app for the iPad, and is intended for release through the Apple App Store.

Posted in: Briefs, TSP, Power Management

Read More >>

Three-Dimensional Photovoltaics Array for Laser-Based Power Transfer

Potential applications include situations in which there is a need to create electrical power at a remote location. Goddard Space Flight Center, Greenbelt, Maryland A standard solar array is a flat panel configured of many individual solar cells, wired in series or parallel, depending on their junction configuration and material. Since the solar flux is constant depending on the distance from the Sun, the maximum energy conversion for a given solar panel depends upon the capability to absorb as many spectral peaks as possible (different materials) across the total solar spectrum. If the radiative source is a man-made device such as a laser, parked in a different orbit or on Earth, then the impinging intensity is narrow spectrally, coherent and accurately pointed, and capable of very high intensities. Thus, the materials can be tailored to match the incoming radiation for maximum absorption.

Posted in: Briefs, TSP, Power Management

Read More >>

Nanowire-Based Piezoelectric Power Generation

Energy scavenging is appealing for powering sensors, and for charging cellphones and small consumer electronics. Ames Research Center, Moffett Field, California Sensors have improved in terms of size, capability, and power consumption, but their deployment in remote areas is limited by battery power supplies. Using piezoelectric (PE) materials for energy scavenging is a possible way to remedy the situation. The technology developed in this work converts existing sources of nonpolluting energy (mechanical strain) from nature into electricity. The quantity of energy produced is not massive, but it can be easily generated from free sources such as vibration and electromagnetic waves.

Posted in: Briefs, Power Management

Read More >>

Tool for Turbine Engine Closed-loop Transient Analysis (TTECTrA)

John H. Glenn Research Center, Cleveland, Ohio The current steady-state performance-based system studies are not adequate to evaluate certain advanced technologies for the challenges associated with meeting the transient performance requirements without better definition and control of component operating margins. Additional dynamic analyses would require more detailed, physics-based, component-level models and controllers in order to better identify dynamic issues that may arise during operation of the engine. The additional complexity in these models increases the effort necessary throughout the design processes, including the system-analysis step. The solution would be a physics-based engine model with full envelope controller. C-MAPSS and C-MAPSS40k are examples of engine models with full envelope controllers, but because they are designed to model a specific engine, they are not good candidates for systems analysis.

Posted in: Briefs, TSP, Electronics & Computers

Read More >>

Wald Sequential Probability Ratio Test for Space Object Conjunction Assessment

The decision procedure is based on targets for false alarm and missed detection rates, along with a prior assessment of the risk of collision, which is independent of the orbit determination. Goddard Space Flight Center, Greenbelt, Maryland When a maneuverable spacecraft confronts a potentially unsafe conjunction with another space object, its operators must decide whether to maneuver to mitigate the risk of a collision. Such decisions may not be straightforward, since the operators must balance their confidence in the predictions that detected the conjunction, the actual likelihood of a collision, any risk inherent in performing the maneuver, interruptions to the mission’s ongoing operations, and long-term consequences such as depletion of consumable propellant. The most common metric for assessing the risk associated with a conjunction is the collision probability.

Posted in: Briefs, Electronics & Computers

Read More >>

Next Generation of 3DGRAPE: Flexible Framework for Hypersonic Navier-Stokes Shuttle Orbiter Meshes

High-fidelity grids were generated rapidly using an assembly line approach with teamwork among NASA centers. Langley Research Center, Hampton, Virginia The class of 3DGRAPE codes is designed to generate volume grids using iterative methods to solve the non-linear, nonhomogeneous, elliptic partial differential heat equation with heat sources. The solution to the heat equation develops three-dimensional discrete points within a domain outside or inside a vehicle where fluid flow is simulated with Computational Fluid Dynamics (CFD). The latest version in this class of software is the 3DGRAPE/AL:V3, version 3 of the Three-Dimensional Grids about Anything by Poisson’s Equation with Upgrades from NASA Ames and Langley computer programs. The previous version, 3DGRAPE/AL:V2 [“Further Improvement in 3DGRAPE,” (LAR-16415-1) NASA Tech Briefs, Vol. 28, No. 9 (September 2004), p. 50], was advanced through the development of a new block-to-block boundary condition that guarantees C-I continuity between adjacent blocks sharing a common block face. Until this condition was developed, matching block faces were only created by projecting a straight line from one cell into each block from the matching face, thereby changing the initial grid that defines a structured multiple block system.

Posted in: Briefs, TSP, Electronics & Computers

Read More >>