The Iron Catalyzed Reaction between Nitrosyl Disulfonate and Hydroxylamine Monosulfonate Ions

Potassium nitrosyl disulfonate, K2NO(SO3)2, is noteworthy because the solid salt is orange in color and diamagnetic while its neutral aqueous solutions are purple in color and paramagnetic. These neutral solutions hydrolyze slowly to form N2O and hydroxylamine sulfonates; on the addition of acid the rate of hydrolysis is markedly increased. The mechanism of the hydrolytic reaction is unexpectedly complex as was found by Murib and Ritter [1] and, independently, by us. In order to obtain a more comprehensive picture of the mechanism of the hydrolytic reaction we have explored additional reactions which may play a part in the hydrolysis

Nondestructive assessment of penetration of electron-beam welds

Empirical method correlates penetration of an electron-beam weld with external measurements of the weld. Empirical polygon accurately confirms full-penetration welds while a second, larger polygon provides for penetration of welds near the tip

Liquid-immersible electrostatic ultrasonic transducer

A broadband megahertz range electrostatic acoustic transducer for use in a liquid environment is described. A liquid tight enclosure includes a metallic conducting membrane as part of its outside surface and has a means inside the liquid tight enclosure for applying a tension to the membrane and for mounting an electrode such that the flat end of the electrode is aproximately parallel to the membrane. The invention includes structure and a method for ensuring that the membrane and the flat end of the electrode are exactly parallel and a fixed predetermined distance from each other

The molecular structure of isocyanic acid from microwave and infra-red absorption spectra

Experimental investigations of the infra-red and microwave spectra of the slightly asymmetric rotor, HNCO, have been made, and the structure of the molecule has been determined

Iron-Catalyzed Reaction between Nitrosyl Disulfonate and Hydroxylamine Monosulfonate Ions

An investigation of the kinetics of the iron-catalyzed reaction between the purple-colored, paramagnetic nitrosyl disulfonate (ON(SO3)2 = ) ions and hydroxylamine monosulfonate (HONHSO3---) ions has been made. [W. J. Ramsey and D. M. Yost, J. Chem. Phys. 21, 957 (1953)]. At a temperature of 20°C, an ionic strength of 0.026, and total added iron concentrations less than 3.5×10^—7 VF, the initial rate of disappearance of ON(SO3)2 = is well represented by the equation: [dformula -((d(ON(SO[sub 3])[sub 2] [equals sign] ))/dt) [equals sign] 2{((k[sub 2]h[sub 1](H[sup +]) + k[sub 3]h[sub 1]h[sub 2])/((H[sup +])[sup 2] + h[sub 1](H[sup +]) + h[sub 1]h[sub 2]))}(Sigma Fe[sup +3])(HONHSO[sub 3][sup -]),] where h1 and h2 are the first and second hydrolysis constants for ferric iron and where k2 and k3 are the specific second-order rate constants for the reactions of HONHSO3--- with Fe(OH) + + and Fe(OH)2 + , respectively. Under the above conditions, and if a value of 3×10^—3 is assumed for h1; h2, k2, and k3 have the values, 7×10^—4 l·mole^—1, 13.7±1.0×10^4 l·mole^—1·min^—1, and 1.5±0.5×10^4 l·mole^—1·min^—1, respectively

Dipole Moment and Electric Quadrupole Effects in HNCO and HNCS

Interaction of the electric quadrupole moment of the nitrogen nucleus with the molecular electric fields of isocyanic and isothiocyanic acids results in a hyperfine splitting of the rotational trnasitions

Predictors of health-related quality of life in patients with colorectal cancer

<p>Abstract</p> <p>Background</p> <p>Most studies that have identified variables associated with the health-related quality of life (HRQL) of patients with colorectal cancer have been cross-sectional or included patients with other diagnoses. The objectives of this study were to identify predictors of HRQL in patients with colorectal cancer and interpret the clinical importance of the results.</p> <p>Methods</p> <p>We conducted a population-based longitudinal study of patients identified through three regions of the California Cancer Registry. Surveys were completed by 568 patients approximately 9 and 19 months post-diagnosis. Three HRQL outcomes from the Functional Assessment of Cancer Therapy – Colorectal (FACT-C) were evaluated: social/family well-being (SWB), emotional well-being (EWB) and the Trial Outcome Index (TOI), which is a colorectal cancer-specific summary measure of physical function and well-being. Sociodemographic, cancer/health, and healthcare variables were assessed in multivariable regression models. We computed the difference in predicted HRQL scores corresponding to a large difference in a predictor variable, defined as a 1 standard deviation difference for interval variables or the difference relative to the reference category for nominal variables. The effect of an explanatory variable on HRQL was considered clinically meaningful if the predicted score difference was at least as large as the minimally important difference.</p> <p>Results</p> <p>Common predictors of better TOI, SWB and EWB were better general health and factors related to better perceived quality of cancer care. Predictor variables in addition to general health and perceived quality of care were identified only for SWB. Being married/living as married was associated with better SWB, whereas being male or of Hispanic ethnicity was associated with worse SWB. Among the sociodemographic, cancer/health, and healthcare variables evaluated, only Hispanic ethnicity had a clinically meaningful effect on an HRQL outcome.</p> <p>Conclusion</p> <p>Our findings, particularly the information on the clinical importance of predictor variables, can help clinicians identify patients who may be at risk for poor future HRQL. Potentially modifiable factors were related to perceived quality of cancer care; thus, future research should evaluate whether improving these factors improves HRQL.</p

XUV Frequency Combs via Femtosecond Enhancement Cavities

We review the current state of tabletop extreme ultraviolet (XUV) sources based on high harmonic generation (HHG) in femtosecond enhancement cavities (fsEC). Recent developments have enabled generation of high photon flux (1014 photons/sec) in the XUV, at high repetition rates (>50 MHz) and spanning the spectral region from 40 nm - 120 nm. This level of performance has enabled precision spectroscopy with XUV frequency combs and promises further applications in XUV spectroscopic and photoemission studies. We discuss the theory of operation and experimental details of the fsEC and XUV generation based on HHG, including current technical challenges to increasing the photon flux and maximum photon energy produced by this type of system. Current and future applications for these sources are also discussed.Comment: invited review article, 38 page

Ramond-Ramond (boundary) states

The description of D-branes as boundary states for type II string theories (in the covariant formulation) requires particular care in the R-R sector. Also the vertices for R-R potentials that can couple to D-branes need a careful handling. As an illustration of this, the example of the D0-D8 system is reviewed, where a ``microscopic'' description of the interaction via exchange of R-R potentials becomes possible.Comment: 8 pages, LaTeX, no figures. Talk presented at the 2nd Conference on Quantum aspects of Gauge Theories, Supersymmetry and Unification, Corfu, Greece, 21-26 September 199

A Late-Time Flattening of Afterglow Light Curves

We present a sample of radio afterglow light curves with measured decay slopes which show evidence for a flattening at late times compared to optical and X-ray decay indices. The simplest origin for this behavior is that the change in slope is due to a jet-like outflow making a transition to sub-relativistic expansion. This can explain the late-time radio light curves for many but not all of the bursts in the sample. We investigate several possible modifications to the standard fireball model which can flatten late-time light curves. Changes to the shock microphysics which govern particle acceleration, or energy injection to the shock (either radially or azimuthally) can reproduce the observed behavior. Distinguishing between these different possibilities will require simultaneous optical/radio monitoring of afterglows at late times.Comment: ApJ, submitte