Radiative Capture on Nuclear Isomers: Direct Measurement of the

We present the first direct measurement of an astrophysical reaction using a radioactive beam of isomeric nuclei. In particular, we have measured the strength of the key 447-keV resonance in the ^{26m}Al(p,γ)^{27}Si reaction to be 432_{-226}^{+146} meV and find that this resonance dominates the thermally averaged reaction rate for temperatures between 0.3 and 2.5 GK. This work represents a critical development in resolving one of the longest standing issues in nuclear astrophysics research, relating to the measurement of proton capture reactions on excited quantum levels, and offers unique insight into the destruction of isomeric ^{26}Al in astrophysical plasmas.

Inverse Kinematic Study of the (26g)Al(d,p)(27)Al Reaction and Implications for Destruction of (26)Al in Wolf-Rayet and Asymptotic Giant Branch Stars.

In Wolf-Rayet and asymptotic giant branch (AGB) stars, the (26g)Al(p,γ)(27)Si reaction is expected to govern the destruction of the cosmic γ-ray emitting nucleus (26)Al. The rate of this reaction, however, is highly uncertain due to the unknown properties of key resonances in the temperature regime of hydrogen burning. We present a high-resolution inverse kinematic study of the (26g)Al(d,p)(27)Al reaction as a method for constraining the strengths of key astrophysical resonances in the (26g)Al(p,γ)(27)Si reaction. In particular, the results indicate that the resonance at E(r)=127 keV in (27)Si determines the entire (26g)Al(p,γ)(27)Si reaction rate over almost the complete temperature range of Wolf-Rayet stars and AGB stars.

A facile manganese dioxide mediated oxidation of primary benzylamines to benzamides.

A high yielding manganese dioxide mediated oxidation of benzylamines to the corresponding amides has been developed under mild reaction conditions. The mechanism for the conversion has been explored by (1)H NMR spectroscopy and the role of both manganese dioxide and molecular sieves in the reaction elucidated.

Is γ-ray emission from novae affected by interference effects in the 18F(p,α)15O reaction?

The (18)F(p,α)(15)O reaction rate is crucial for constraining model predictions of the γ-ray observable radioisotope (18)F produced in novae. The determination of this rate is challenging due to particular features of the level scheme of the compound nucleus, (19)Ne, which result in interference effects potentially playing a significant role. The dominant uncertainty in this rate arises from interference between J(π)=3/2(+) states near the proton threshold (S(p)=6.411 MeV) and a broad J(π)=3/2(+) state at 665 keV above threshold. This unknown interference term results in up to a factor of 40 uncertainty in the astrophysical S-factor at nova temperatures. Here we report a new measurement of states in this energy region using the (19)F((3)He,t)(19)Ne reaction. In stark contrast to previous assumptions we find at least 3 resonances between the proton threshold and E(cm)=50 keV, all with different angular distributions. None of these are consistent with J(π)=3/2(+) angular distributions. We find that the main uncertainty now arises from the unknown proton width of the 48 keV resonance, not from possible interference effects. Hydrodynamic nova model calculations performed indicate that this unknown width affects (18)F production by at least a factor of two in the model considered.

The use of epidemiology in decision making by hospital executives.

The study has shown that epidemiological data are not used as often as they should be. The results suggest that education level has an impact on the use of epidemiology in long-term and short-term decision making. The higher the education level, the more use of epidemiology is suggested. Individuals with an MPH (Master's of Public Health) degree used epidemiological data on a higher frequency than did their peers. A possible suggestion as to why this occurs is that those individuals who had an MPH more than likely have had a course in epidemiology and understand how to utilize it. Of the individuals who did not use epidemiology, 98.7 percent attributed that to either cost or language that was unfamiliar to them. Of these individuals, 65.8 percent said they would be interested in learning more about epidemiology, and 64.5 percent said they would use it if they were more familiar. A need for instruction in epidemiology was revealed by this survey. Epidemiology should be used to perform studies on the regional population to identify the needs of the hospital's consumers. Without the knowledge base, this is not being done; possible continuing education for administrators covering the uses of epidemiology could work toward correcting the problem.