SSME structural dynamic model development

A mathematical model of the Space Shuttle Main Engine (SSME) as a complete assembly, with detailed emphasis on LOX and High Fuel Turbopumps is developed. The advantages of both complete engine dynamics, and high fidelity modeling are incorporated. Development of this model, some results, and projected applications are discussed

Macartney Rose Control Systems.

4 p

Optical processing for distributed sensors in control of flexible spacecraft

A recent potential of distributed image processing is discussed. Applications in the control of flexible spacecraft are emphasized. Devices are currently being developed at NASA and in universities and industries that allow the real-time processing of holographic images. Within 5 years, it is expected that, in real-time, one may add or subtract holographic images at optical accuracy. Images are stored and processed in crystal mediums. The accuracy of their storage and processing is dictated by the grating level of laser holograms. It is far greater than that achievable using current analog-to-digital, pixel oriented, image digitizing and computing techniques. Processors using image processing algebra can conceptually be designed to mechanize Fourier transforms, least square lattice filters, and other complex control system operations. Thus, actuator command inputs derived from complex control laws involving distributed holographic images can be generated by such an image processor. Plans are revealed for the development of a Conjugate Optics Processor for control of a flexible object

Macartney Rose Control Systems.

4 p

Single-Scattering Optical Tomography: Simultaneous Reconstruction of Scattering and Absorption

We demonstrate that simultaneous reconstruction of scattering and absorption of a mesoscopic system using angularly-resolved measurements of scattered light intensity is possible. Image reconstruction is realized based on the algebraic inversion of a generalized Radon transform relating the scattering and absorption coefficients of the medium to the measured light intensity and derived using the single-scattering approximation to the radiative transport equation.Comment: This is a sequel to physics/070311

Effluent travel estimates from ships anchored in Chesapeake Bay : a report to the Virginia State Water Control Board

As the world demand for coal has increased, the number of colliers arriving at Hampton Roads, Virginia, to load coal has exceeded the ability of the port to supply the demand. As a result, a substantial backlog of ships waiting to load coal is presently taxing the anchorage capacity of the harbor. A recent estimate is that 130 ships are waiting about 38 days each for their turn at the loading factl1t1es. In addition to the anchorages tn Hampton Roads and the lower James River, new anchorages have been opened to accomodate these ships, one on the southern side of the Chesapeake Bay entrance, off Lynnhaven and the other to the west of Cape Charles. Each of these ships. in maintaining a crew aboard, produces waste materials of several varities which are mixed with the water surrounding the vessel as it lies at anchor. In order to estimate the impacts which this effluent may have on the various aspects of Chesapeake Bay, it is first necessary to estimate the motion of the effluents subsequent to leaving their ships. This report, based on previous experimental work in the region. is intended to provide such an estimate

Single-cell analysis of the 3D topologies of genomic loci using genome architecture mapping

Although each cell within an organism contains a nearly identical genome sequence, the three-dimensional (3D) packing of the genome varies among individual cells, influencing cell-type-specific gene expression. Genome Architecture Mapping (GAM) is the first genome-wide experimental method for capturing 3D proximities between any number of genomic loci without ligation. GAM overcomes several limitations of 3C-based methods by sequencing DNA from a large collection of thin sections sliced from individual nuclei. The GAM technique measures locus co-segregation, extracts radial positions, infers chromatin compaction, requires small numbers of cells, does not depend on ligation, and provides rich single-cell information. However, previous analyses of GAM data focused exclusively on population averages, neglecting the variation in 3D topology among individual cells. We present the first single-cell analysis of GAM data, demonstrating that the slices from individual cells reveal intercellular heterogeneity in chromosome conformation. By simultaneously clustering both slices and genomic loci, we identify topological variation among single cells, including differential compaction of cell cycle genes. We also develop a geometric model of the nucleus, allowing prediction of the 3D positions of each slice. Using GAM data from mouse embryonic stem cells, we make new discoveries about the structure of the major mammalian histone gene locus, which is incorporated into the Histone Locus Body (HLB), including structural fluctuations and putative causal molecular mechanisms. Our methods are packaged as SluiceBox, a toolkit for mining GAM data. Our approach represents a new method of investigating variation in 3D genome topology among individual cells across space and time

Anomalous increase in nematic-isotropic transition temperature in dimer molecules induced by magnetic field

We have determined the nematic-isotropic transition temperature as a function of applied magnetic field in three different thermotropic liquid crystalline dimers. These molecules are comprised of two rigid calamitic moieties joined end to end by flexible spacers with odd numbers of methylene groups. They show an unprecedented magnetic field enhancement of nematic order in that the transition temperature is increased by up to 15K when subjected to 22T magnetic field. The increase is conjectured to be caused by a magnetic field-induced decrease of the average bend angle in the aliphatic spacers connecting the rigid mesogenic units of the dimers