NPMS

Thesis (S.M. in Naval Architecture and Marine Engineering and S.M. in Mechanical Engineering)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 73).This thesis presents an approach to the structural design and optimization of a non-pressurized manned submersible (NPMS), a type of fully "flooded" submersible based on a SEAL Delivery Vehicle (SDV) Design Concept. Using the design parameters determined by the mathematical model, a solid model was generated and an ANSYS goal-driven optimizer was used to further optimize the hull weldment and variable ballast tanks. When three different designs were subsequently evaluated to verify the parametric model and the scalability of the NPMS design concept, all three were found to be able to be successfully generated and to meet the stated design requirements after ANSYS optimization. These findings indicate that the approach presented in this thesis can be used as an initial design tool in the future design of NPMSs.by Kenneth Shepard.S.M.in Naval Architecture and Marine Engineering and S.M.in Mechanical Engineerin

TB152: The Effect of Juvenile Wood on the Properties of Aspen Flakeboard

While the effects of juvenile wood tissue on solid wood products and paper have been known for some time, little information is available regarding its influence on structural flakeboard. Juvenile and mature wood tissue were identified b y their physical and mechanical properties in quaking aspen (Populus tremuloides Michx.). Sections of juvenile and mature wood were separated from 1-foot bolts of aspen. These sections were used to prepare three distinct types of structural flakeboard : juvenile wood-based, mature wood-based, and one formed from an equal mixture of the two. The panels were tested for selected mechanical and physical properties. The juvenile wood-based panels performed significantly better than the mature wood-based in respect to modulus of rupture, thickness swell, and water absorption, while also exhibiting somewhat higher values for modulus of elasticity, internal bond strength, compressive shear strength, and linear expansion. The panels made with a mixture of the two types of flakes did not display some of the poorer characteristics of the mature wood panels.https://digitalcommons.library.umaine.edu/aes_techbulletin/1052/thumbnail.jp

Integrated circuit-based electrochemical sensor for spatially resolved detection of redox-active metabolites in biofilms

Despite advances in monitoring spatiotemporal expression patterns of genes and proteins with fluorescent probes, direct detection of metabolites and small molecules remains challenging. A technique for spatially resolved detection of small molecules would benefit the study of redox-active metabolites that are produced by microbial biofilms and can affect their development. Here we present an integrated circuit-based electrochemical sensing platform featuring an array of working electrodes and parallel potentiostat channels. ‘Images’ over a 3.25 0.9 mm2 area can be captured with a diffusion-limited spatial resolution of 750 mm. We demonstrate that square wave voltammetry can be used to detect, identify and quantify (for concentrations as low as 2.6 mM) four distinct redox-active metabolites called phenazines. We characterize phenazine production in both wild-type and mutant Pseudomonas aeruginosa PA14 colony biofilms, and find correlations with fluorescent reporter imaging of phenazine biosynthetic gene expression

High-density integration of ultrabright OLEDs on a miniaturized needle-shaped CMOS backplane

This work was supported in part by the Defense Advanced Research Projects Agency (DARPA) under Contract N6600117C4012, by the National Institutes of Health under Grant U01NS090596, and by the Leverhulme Trust (RPG-2017-231). C.K.M. acknowledges funding from the European Commission through a Marie Skłodowska Curie individual fellowship (101029807). M.C.G. acknowledges funding from the Alexander von Humboldt Stiftung (Humboldt-Professorship). We thank Aaron Naden for the FIB/STEM measurements (Engineering and Physical Sciences Research Council under grant numbers EP/L017008/1, EP/R023751/1 and EP/T019298/1).Direct deposition of organic light-emitting diodes (OLEDs) on silicon-based complementary metal–oxide–semiconductor (CMOS) chips has enabled self-emissive microdisplays with high resolution and fill-factor. Emerging applications of OLEDs in augmented and virtual reality (AR/VR) displays and in biomedical applications, e.g., as brain implants for cell-specific light delivery in optogenetics, require light intensities orders of magnitude above those found in traditional displays. Further requirements often include a microscopic device footprint, a specific shape and ultrastable passivation, e.g., to ensure biocompatibility and minimal invasiveness of OLED-based implants. In this work, up to 1024 ultrabright, microscopic OLEDs are deposited directly on needle-shaped CMOS chips. Transmission electron microscopy and energy-dispersive X-ray spectroscopy are performed on the foundry-provided aluminum contact pads of the CMOS chips to guide a systematic optimization of the contacts. Plasma treatment and implementation of silver interlayers lead to ohmic contact conditions and thus facilitate direct vacuum deposition of orange- and blue-emitting OLED stacks leading to micrometer-sized pixels on the chips. The electronics in each needle allow each pixel to switch individually. The OLED pixels generate a mean optical power density of 0.25 mW mm−2, corresponding to >40 000 cd m−2, well above the requirement for daylight AR applications and optogenetic single-unit activation in the brain.Publisher PDFPeer reviewe

A Single-Photon Avalanche Diode Imager for Fluorescence Lifetime Applications

A 64-by-64-pixel CMOS single-photon avalanche diode (SPAD) imager for time-resolved fluorescence detection features actively quenched and reset pixels, allowing gated detection to eliminate pile-up nonlinearities common to most time-correlated single-photon counting (TCSPC) approaches. Timing information is collected using an on-chip time-to-digital converter (TDC) based on a counter and a supply-regulated delay-locked loop (DLL)

Race to the Bottom: Malicious Hardware

Increasingly, hardware design and fabrication has come to resemble that of software: hardware logic modules (resembling software libraries) are licensed from third parties and combined in designs of greater complexity, while the fabrication is outsourced to a low-cost manufacturer or otherwise off-shored

The Wooster Voice (Wooster, OH), 1997-10-16

This edition of the College of Wooster student run newspaper was published on October 16 of 1997 and it is twelve pages long. Jilted surgeon general calls for more health education, Dr. Jocelyn Elders presents during the Wooster Forum series about health care and education. Ebert to be dedicated this weekend, the Ebert Art Center is going to be formally dedicated. Renowned musical trio combines classical with new, the Cleveland Duo and saxophonist James Umble perform at the Gault Recital Hall. Athletic updates for the past week are highlighted on pages ten to twelve.https://openworks.wooster.edu/voice1991-2000/1177/thumbnail.jp

Composition of Near-Earth Asteroid 2008 EV5: Potential target for Robotic and Human Exploration

We observed potentially hazardous asteroid (PHA) 2008 EV5 in the visible (0.30-0.92 microns) and near-IR (0.75-2.5 microns) wavelengths to determine its surface composition. This asteroid is especially interesting because it is a potential target for two sample return mission proposals (Marco Polo-R and Hayabusa-2) and human exploration due to its low delta-v for rendezvous. The spectrum of 2008 EV5 is essentially featureless with exception of a weak 0.48-microns spin-forbidden Fe3+ absorption band. The spectrum also has an overall blue slope. The albedo of 2008 EV5 remains uncertain with a lower limit at 0.05 and a higher end at 0.20 based on thermal modeling. The Busch et al. (2011) albedo estimate of 0.12 is consistent with our thermal modeling results. The albedo and composition of 2008 EV5 are also consistent with a C-type taxonomic classification (Somers et al. 2008). The best spectral match is with CI carbonaceous chondrites similar to Orgueil, which also have a weak 0.48-microns feature and an overall blue slope. This 0.48-microns feature is also seen in the spectrum of magnetite. The albedo of CI chondrites is at the lower limit of our estimated range for the albedo of 2008 EV5.Comment: Pages: 19 Figures: 6 Tables: