Passive Self-Healing Composite Dielectric Elastomer Sensors for Structural Health Monitoring of Inflatable Space Structures

According to NASA, there exists more than 100 million pieces of Micrometeoroids and Orbital Debris (MMOD) in Low Earth Orbit traveling at an average speed of 9 kilometers per second, or about 20,000 miles per hour, that cannot currently be tracked with modern technology. With long duration spaceflight becoming a reality as the space industry looks to return to the moon, this time to stay, engineers have been tasked with developing habitats where astronauts can live and work safely for months or even years at a time while avoiding the many hazards of space, especially MMOD. To assist in the detection and improve the safety of space structures, the demonstrated work establishes the fabrication of a passive self-healing composite dielectric elastomer sensor to be utilized for the structural health monitoring (SHM) of inflatable space structures. With funding from NASA through the Florida Space Grant Consortium, ERAU’s Office of Undergraduate Research, and ERAU’s College of Engineering, hyper-velocity impact testing (HVIT) was performed at the Impact Physics Laboratory at the University of Dayton Research Institute to demonstrate scientific significance in self-healing capability and a measurable change in capacitance associated with impact damage, including penetration depth. Additionally, the sensing system’s ability to measure impact velocity and operate passively was addressed

Tailoring 3D Speckle Statistics

We experimentally generate three-dimensional speckles with customized intensity statistics. By modulating the phase front of a laser beam, far-field speckle patterns maintain the designed intensity probability density function while evolving to different spatial patterns upon axial propagation. We also create speckles with distinct intensity statistics at multiple designated planes. These results open many new possibilities, such as designing volumetric speckle statistics for three-dimensional imaging, sensing, trapping, and manipulation.Comment: 6 pages, 4 figure

Sum Rules for Energy Deposition Eigenchannels in Scattering Systems

In a random-scattering system, the deposition matrix maps the incident wavefront onto the internal field distribution across a target volume. The corresponding eigenchannels have been used to enhance the wave energy delivered to the target. Here, we find the sum rules for the eigenvalues and eigenchannels of the deposition matrix in any system geometry: including two- and three-dimensional scattering systems, as well as narrow waveguides and wide slabs. We derive a number of constraints on the eigenchannel intensity distributions inside the system as well as the corresponding eigenvalues. Our results are general and applicable to random systems of arbitrary scattering strength as well as different types of waves including electromagnetic waves, acoustic waves, and matter waves

On voxel-by-voxel accumulated dose for prostate radiation therapy using deformable image registration.

Since delivered dose is rarely the same with planned, we calculated the delivered total dose to ten prostate radiotherapy patients treated with rectal balloons using deformable dose accumulation (DDA) and compared it with the planned dose. The patients were treated with TomoTherapy using two rectal balloon designs: five patients had the Radiadyne balloon (balloon A), and five patients had the EZ-EM balloon (balloon B). Prostate and rectal wall contours were outlined on each pre-treatment MVCT for all patients. Delivered fractional doses were calculated using the MVCT taken immediately prior to delivery. Dose grids were accumulated to the last MVCT using DDA tools in Pinnacle3 TM (v9.100, Philips Radiation Oncology Systems, Fitchburg, USA). Delivered total doses were compared with planned doses using prostate and rectal wall DVHs. The rectal NTCP was calculated based on total delivered and planned doses for all patients using the Lyman model. For 8/10 patients, the rectal wall NTCP calculated using the delivered total dose was less than planned, with seven patients showing a decrease of more than 5% in NTCP. For 2/10 patients studied, the rectal wall NTCP calculated using total delivered dose was 2% higher than planned. This study indicates that for patients receiving hypofractionated radiotherapy for prostate cancer with a rectal balloon, total delivered doses to prostate is similar with planned while delivered dose to rectal walls may be significantly different from planned doses. 8/10 patients show significant correlation between rectal balloon anterior-posterior positions and some VD values

Fluctuations and correlations of transmission eigenchannels in diffusive media

Selective excitation of a diffusive system's transmission eigenchannels enables manipulation of its internal energy distribution. The fluctuations and correlations of the eigenchannels' spatial profiles, however, remain unexplored so far. Here we show that the depth profiles of high-transmission eigenchannels exhibit low realization-to-realization fluctuations. Furthermore, our experimental and numerical studies reveal the existence of inter-channel correlations, which are significant for low-transmission eigenchannels. Because high-transmission eigenchannels are robust and independent from other eigenchannels, they can reliably deliver energy deep inside turbid media

Spectral Speckle Customization

Speckle patterns are used in a broad range of applications including microscopy, imaging, and light-matter interactions. Tailoring speckles' statistics can dramatically enhance their performance in applications. We present an experimental technique for customizing the spatio-spectral speckled intensity statistics of optical pulses at the output of a complex medium (a disordered multimode fiber) by controlling the spatial profile of the input light. We demonstrate that it is possible to create ensembles of independent speckle patterns with arbitrary statistics at a single wavelength, simultaneously at decorrelated wavelengths, and even tailored statistics across an entire pulse spectrum

Exploring Cloud Computing Adoptions in Public Sectors: A Case Study

Despite the number of benefits cloud computingtechnology has to offer all organizations, both public and private,risk elements to consider still remain. Previously, these elementswere used in evaluating if an organization would move towardsthe cloud or not. Today, it is no longer a question of if, but aquestion of when. The task of evaluating the benefits and risks isnow part of the gap analysis used to determine which vendor tocontract with. In the public sector, government entities face adifferent set of rules and higher scrutiny when it comes to datasecurity and budgeting. By evaluating what steps early adoptershave taken in their investigation and analysis processes prior tochoosing a vendor, this paper explores the essential informationabout cloud computing adoptions in public sectors and providessome guidelines that governments can use in their decisionmaking process when considering cloud services