Image enhancement software for underwater recovery operations - user's manual

This report describes software for performing image enhancement on live or recorded video images. The software was developed for operational use during underwater recovery operations at the Naval Undersea Warfare Engineering Station. The image processing is performed on an IBM-PC/AT compatible computer equipped with hardware to digitize and display video images. The software provides the capability to provide contrast enhancement and other similar functions in real time through hardware lookup tables, to automatically perform histogram equalization, to capture one or more frames and average them or apply one of several different processing algorithms to a captured frame. The report is in the form of a user manual for the software and includes guided tutorial and reference sections. A Digital Image Processing Primer in the appendix serves to explain the principle concepts that are used in the image processing. (rrh)http://archive.org/details/imageenhancement00partApproved for public release; distribution is unlimited

Experimental Assessment and Enhancement of Planar Laser-Induced Fluorescence Measurements of Nitric Oxide in an Inverse Diffusion Flame

We have experimentally assessed the quantitative nature of planar laser-induced fluorescence (PLIF) measurements of NO concentration in a unique atmospheric pressure, laminar, axial inverse diffusion flame (IDF). The PLIF measurements were assessed relative to a two-dimensional array of separate laser saturated fluorescence (LSF) measurements. We demonstrated and evaluated several experimentally-based procedures for enhancing the quantitative nature of PLIF concentration images. Because these experimentally-based PLIF correction schemes require only the ability to make PLIF and LSF measurements, they produce a more broadly applicable PLIF diagnostic compared to numerically-based correction schemes. We experimentally assessed the influence of interferences on both narrow-band and broad-band fluorescence measurements at atmospheric and high pressures. Optimum excitation and detection schemes were determined for the LSF and PLIF measurements. Single-input and multiple-input, experimentally-based PLIF enhancement procedures were developed for application in test environments with both negligible and significant quench-dependent error gradients. Each experimentally-based procedure provides an enhancement of approximately 50% in the quantitative nature of the PLIF measurements, and results in concentration images nominally as quantitative as LSF point measurements. These correction procedures can be applied to other species, including radicals, for which no experimental data are available from which to implement numerically-based PLIF enhancement procedures

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The influence of hydroxyapatite nanoparticles on human mesenchymal stromal cells : application in tissue engineered constructs

PhD ThesisOsteoarthritis (OA) is a debilitating disease characterised by degradation of the articular cartilage and changes in the subchondral bone. Presently the gold standard treatment for OA is total joint replacement using metal, ceramic and non-degradable polymer materials. Tissue engineering using novel bioresorbable biomaterials has the potential to stimulate regeneration of bone and cartilage for early stage intervention in OA suffers. This thesis investigates the synthesis of hydroxyapatite nanoparticles (HAp) and techniques to generate poly (lactic acid) (PLA) HAp nanocomposites. The effect of the synthesised HAp on isolated OA donor derived human mesenchymal stem cells (hMSC) was investigated in both 2D and 3D culture conditions. A highly controllable sol-gel synthesis method demonstrated control over HAp morphology and composition, with modification of titration rate, addition methodology and reaction pH. Two novel nanocomposite fabrication techniques were developed and characterised with transmission electron microscopy (TEM) demonstrating HAp dispersion at the nanoscale throughout PLA. Dip-coated HAp PLA and fibrin substrates were fabricated and demonstrated maintenance of hMSC adherence, proliferation and osteogenesis on 2D substrates. Investigations into fibrin encapsulated hMSC illustrated HAp uptake within the cell following 24 hours incubation. Further studies examining fibrin/HAp encapsulated hMSC showed increased osteogenic gene expression, peripheral matrix deposition and mineralisation following 21 days in culture. 3D printed PLA constructs infused with fibrin and fibrin/HAp encapsulated hMSC demonstrated significant osteogenic gene expression differences at day 21. However, these data were variable between cell isolations from different patients further illustrating hMSC heterogeneity and hMSC donor–donor variability in-vitro.Arthritis Research U