An experimental study to discriminate between the validity of diffraction theories for off-Bragg replay

We show that experiments clearly verify the assumptions made by the first-order two-wave coupling theory for one dimensional lossless unslanted planar volume holographic gratings using the beta-value method rather than Kogelnik's K-vector closure method. Apart from the fact that the diffraction process is elastic, a much more striking difference between the theories becomes apparent particularly in the direction of the diffracted beam in off-Bragg replay. We therefore monitored the direction of the diffracted beam as a function of the off-Bragg replay angle in two distinct cases: [a] the diffracted beam lies in the plane of incidence and [b] the sample surface normal, the grating vector and the incoming beam do not form a plane which calls for the vectorial theory and results in conical scattering.Comment: Corrected Eqs. (3) & (6); 14 pages, 8 figure

Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial change

Determination of the effects of sulfur dioxide on recovery systems for CO/sub 2/. Final report, 1977-1980

The present study was initiated to investigate the problems associated with recovery of CO/sub 2/ from flue gases for enhanced oil recovery. In particular, the scope of this work may be stated: determine the type of impurities formed in ammonia, monoethanolamine (MEA), and potassium carbonate systems when extracting CO/sub 2/ from oxidizing flue gases containing nitrogen oxides and sulfur oxides; determine the levels of impurity build-up in the solvents; estimate the impurity level in the recovered CO/sub 2/; evaluate the effect on corrosion in metals by these solvents in a flue gas environment; determine the carbon-dioxide absorption coefficients in solvents contaminated due to the pollutants present in the flue gas; evaluate the effect of particulate matter on absorption coefficients in the solvents; and recommend potential absorption systems for CO/sub 2/ from flue gas and estimate the cost of recovery. The results of this study indicate that in ammonia, ammonia sulfate is quickly formed to render that portion of the absorbent inactive. In MEA, amine sulfite and amine sulfate are the dominant impurities formed. In amine-activated potassium carbonate solutions, only sulfite and sulfate ions were found. No nitrogen-oxide species were found in any solution. The impurity levels obtained in the present experiments indicated no limit on contaminant build-up. The impurity level in the recovered CO/sub 2/ was estimated to be less than or equal to 100 ppM non-condensible gases, 20 to 200 ppM SO/sub 2/, and < 20 ppM NO/sub x. Corrosion in the absorption systems will be similar to that observed in CO/sub 2/ absorption systems from reducing gas streams. The absorption rate of CO/sub 2/ in solutions decreases with increasing loading of CO/sub 2/ in almost a linear fashion. Several alternative absorption systems were evaluated in a preliminary cost evaluation, and a K/sub 2/CO/sub 3/ (EAE activated) solution was recommended

Physical characterization of radioactive sludges in selected Melton Valley and evaporator facility storage tanks

Physical measurements were performed on typical radioactive sludge samples from selected Melton Valley Storage Tanks (MVSTs) and evaporator facility storage tanks at ORNL. These measurements included viscosity, particle size, density, sedimentation rate, and solids content. The techniques developed during this project are simple and use inexpensive apparatus to assay the range of physical properties spanned by the sample set. The report provides data in support of the design of the proposed Waste Handling and Packaging Plant, and research and development activities in developing waste management alternatives. 5 refs., 11 figs., 6 tabs

Behavior of hybrid FRP-concrete-steel double-skin tubular columns with a square outer tube and a circular innert tube subjected to axial compression

Hybrid fiber-reinforced polymer (FRP) concrete steel, double skin tubular columns (DSTCs) are a new form of hybrid columns. The most common sectional form of hybrid DSTCs consists of a layer of concrete sandwiched between a circular inner steel tube and a circular outer FRP tube whose fiber directions are close to the hoop detection to provide effective confinement to the concrete. Much recent research has been conducted on circular hybrid DSTCs, which has demonstrated that the combination of the three constituent materials leads to several advantages not available with existing forms of columns. In practical applications, for aesthetic and other reasons, square hybrid DSTCs may be needed. This paper thus extends the existing work on circular hybrid DSTCs to square hybrid DSTCs in which the outer FRP tube is square while the inner steel tube is still circular. Results from a series of axial compression tests are presented and interpreted to examine the compressive behavior of square hybrid DSTCs. In these tests, FRP tubes formed through a wet-layup process were used instead of filament-wound FRP tubes because the latter were not readily available to the authors at the time of the study. The test results show that the concrete in these square hybrid DSTCs is effectively confined by the two tubes, and the behavior of the confined concrete is similar to that of concrete in FRP-confined solid columns. A stress-strain model for concrete in square hybrid DSTCs is also proposed and is shown to provide reasonably accurate predictions of the test results. DOI: 10.1061/(ASCE)CC.1943-5614.0000331. (C) 2013 American Society of Civil Engineers