Ultrasonic detection of flaws in fusion butt welds

Reliable and accurate Delta technique, a nondestructive ultrasonics method, uses redirection of energy to detect randomly oriented imperfections in fusion butt welds. Data on flaws can be read from either an oscilloscope or a printout

The Absorption Spectra of Derivatives of Phthalic Anhydride

The organic qualitative reagent 3-nitrophthalic anhydride has been found useful in the characterization of alcohols and mercaptans. It is of particular interest to note that in the products formed by the reaction of this reagent with alcohols the ester group is uniformly ortho to the nitro group rather than meta. Similarly it has been noted that the reaction of quinolinic anhydride with methyl alcohol likewise gives the a-methyl ester (Kirpal, 1907). On the other hand, the reaction between methyl alcohol and 4-nitrophthalic anhydride or cinchomeronic anhydride results in the formation of derivatives in which the ester group is para to the nitro group or to the heterocyclic nitrogen (Wegscheider and v. Dubrav, 1903; Goldschmiedt and Strache, 1889)

Correlation of chlorophyll, suspended matter, and related parameters of waters in the lower Chesapeake Bay area to LANDSAT-1 imagery

The author has identified the following significant results. An effort to relate water parameters of the lower Chesapeake Bay area to multispectral scanner images of LANDSAT 1 has shown that some spectral bands can be correlated to water parameters, and has demonstrated the feasibility of synoptic mapping of estuaries by satellite. Bands 5 and 6 were shown to be useful for monitoring total particles. Band 5 showed high correlation with suspended sediment concentration. Attenuation coefficients monitored continuously by ship along three baselines were cross correlated with radiance values on three days. Improved correlations resulted when tidal conditions were taken into consideration. A contouring program was developed to display sediment variation in the lower Chesapeake Bay from the MSS bands

Correlation of ERTS multispectral imagery with suspended matter and chlorophyll in lower Chesapeake Bay

The feasibility of using multispectral satellite imagery to monitor the characteristics of estuarine waters is being investigated. Preliminary comparisons of MSS imagery with suspended matter concentrations, particle counts, chlorophyll, transmittance and bathymetry have been made. Some visual correlation of radiance with particulates and chlorophyll has been established. Effects of bathymetry are present, and their relation to transmittance and radiance is being investigated. Greatest detail in suspended matter is revealed by MSS band 5. Near-surface suspended sediment load and chlorophyll can be observed in bands 6 and 7. Images received to date have partially defined extent and location of high suspensate concentrations. Net quantity of suspended matter in the lower Bay has been decreasing since the inception of the study, and represents the diminution of turbid flood waters carried into the Bay in late September, 1972. The results so far point to the utility of MSS imagery in monitoring estuarine water character for the assessment of siltation, productivity, and water types

Evolution of the bilayer nu = 1 quantum Hall state under charge imbalance

We use high-mobility bilayer hole systems with negligible tunneling to examine how the bilayer nu = 1 quantum Hall state evolves as charge is transferred from one layer to the other at constant total density. We map bilayer nu = 1 state stability versus imbalance for five total densities spanning the range from strongly interlayer coherent to incoherent. We observe competition between single-layer correlations and interlayer coherence. Most significantly, we find that bilayer systems that are incoherent at balance can develop spontaneous interlayer coherence with imbalance, in agreement with recent theoretical predictions.Comment: 4 pages, 4 figure

Programmed buckling by controlled lateral swelling in a thin elastic sheet

Recent experiments have imposed controlled swelling patterns on thin polymer films, which subsequently buckle into three-dimensional shapes. We develop a solution to the design problem suggested by such systems, namely, if and how one can generate particular three-dimensional shapes from thin elastic sheets by mere imposition of a two-dimensional pattern of locally isotropic growth. Not every shape is possible. Several types of obstruction can arise, some of which depend on the sheet thickness. We provide some examples using the axisymmetric form of the problem, which is analytically tractable.Comment: 11 pages, 9 figure

Microencapsulation of Corrosion Indicators for Smart Coatings

A multifunctional smart coating for the autonomous detection, indication, and control of corrosion is been developed based on microencapsulation technology. This paper summarizes the development, optimization, and testing of microcapsules specifically designed for early detection and indication of corrosion when incorporated into a smart coating. Results from experiments designed to test the ability of the microcapsules to detect and indicate corrosion, when blended into several paint systems, show that these experimental coatings generate a color change, indicative of spot specific corrosion events, that can be observed with the naked eye within hours rather than the hundreds of hours or months typical of the standard accelerated corrosion test protocols.. Key words: smart coating, corrosion detection, microencapsulation, microcapsule, pH-sensitive microcapsule, corrosion indicator, corrosion sensing pain

Alcohol Use Trajectories after High School Graduation among Emerging Adults with Type 1 Diabetes

Objective Explore alcohol involvement trajectories and associated factors during the year post-high school (HS) graduation among emerging adults with type 1 diabetes. Methods Youth (N=181) self-reported alcohol use at baseline and every 3 months for 1 year post-HS graduation. Data were also collected on parent-youth conflict, diabetes self-efficacy, major life events, living and educational situations, diabetes management, marijuana use, cigarette smoking, and glycemic control. Trajectories of alcohol use were modeled using latent class growth analysis. Associations between trajectory class and specific salient variables were examined using analysis of variance, chi square, or generalized linear mixed model, as appropriate. Results Identified alcohol involvement trajectory classes were labeled as: 1) Consistent Involvement Group (n=25, 13.8%) with stable, high use relative to other groups over the 12 months; 2) Growing Involvement Group (n=55, 30.4%) with increasing use throughout the 12 months; and 3) Minimal Involvement Group (n=101, 55.8%) with essentially no involvement until month nine. Those with minimal involvement had the best diabetes management and better diabetes self-efficacy than those with consistent involvement. In comparison to those minimally involved, those with growing involvement were more likely to live independently of parents; those consistently involved had more major life events; and both the growing and consistent involvement groups were more likely to have tried marijuana and cigarettes. Conclusions This sample of emerging adults with type 1 diabetes has 3 unique patterns of alcohol use during the first year after high school. Implication and Contribution Among youth with type 1 diabetes in the year post-HS graduation, alcohol involvement knowledge was extended by identifying patterns of such use. Further research of alcohol use patterns is needed to guide health care professionals in their assessments and researchers in testing interventions that target unique patterns