Unambiguous identification of the second 2+ state in 12C and the structure of the Hoyle state.

The second J(π)=2+ state of 12C, predicted over 50 years ago as an excitation of the Hoyle state, has been unambiguously identified using the 12C(γ,α0)(8)Be reaction. The alpha particles produced by the photodisintegration of 12C were detected using an optical time projection chamber. Data were collected at beam energies between 9.1 and 10.7 MeV using the intense nearly monoenergetic gamma-ray beams at the HIγS facility. The measured angular distributions determine the cross section and the E1-E2 relative phases as a function of energy leading to an unambiguous identification of the second 2+ state in 12C at 10.03(11) MeV, with a total width of 800(130) keV and a ground state gamma-decay width of 60(10) meV; B(E2:2(2)+→0(1)+)=0.73(13)e(2) fm(4) [or 0.45(8) W.u.]. The Hoyle state and its rotational 2+ state that are more extended than the ground state of 12C presents a challenge and constraints for models attempting to reveal the nature of three alpha-particle states in 12C. Specifically, it challenges the ab initio lattice effective field theory calculations that predict similar rms radii for the ground state and the Hoyle state.

Quantitative discrimination between oil and water in drilled bore cores via Fast-Neutron Resonance Transmission Radiography.

A novel method utilizing the Fast Neutron Resonance Transmission Radiography is proposed for non-destructive, quantitative determination of the weight percentages of oil and water in cores taken from subterranean or underwater geological formations. The ability of the method to distinguish water from oil stems from the unambiguously-specific energy dependence of the neutron cross-sections for the principal elemental constituents. Monte-Carlo simulations and initial results of experimental investigations indicate that the technique may provide a rapid, accurate and non-destructive method for quantitative evaluation of core fluids in thick intact cores, including those of tight shales for which the use of conventional core analytical approaches appears to be questionable.

Histamine and pulmonary responses to cigarette smoke in periphery of the lung.

An animal model for studying responses of the lung periphery to controlled levels of environmental agents has been used to assess the role of histamine in pulmonary responses to cigarette smoke. A fiber-optic bronchoscope was wedged in a peripheral airway of anesthetized dogs. Measurements of collateral resistance (Rcoll) were used to monitor responses to histamine and cigarette smoke. Responses to an aerosol containing histamine (1.5 X 10(-4) mg) and cigarette smoke (420 ml) were measured before and after the administration of an aerosol containing 1.0 mg chlorpheniramine. Prior to the administration of chlorpheniramine, the histamine challenge produced a 75 +/- 26% increase in Rcoll and cigarette smoke produced a 74 +/- 26% increase. Following the administration of chlorpheniramine, the peak responses to histamine and cigarette smoke were reduced by 82 +/- 9 and 61 +/- 8%, respectively. Administration of the same dose of chlorpheniramine prior to challenge with methacholine did not reduce the response to that agent. These results indicate that acute local responses to cigarette smoke in the periphery of the lung are mediated in part through the release of histamine.