Food safety

Illness induced by unsafe food is a problem of great public health significance. This study relates exclusively to the occurrence of chemical agents which will result in food unsafe for human consumption since the matter of food safety is of paramount importance in the mission and operation of the manned spacecraft program of the National Aeronautics and Space Administration

Problems Associated With the Expenditure of the Energy of Particles and Radiations

Abstract Not Provided

Corrigendum. Maars to calderas: end-members on a spectrum of explosive volcanic depressions

A corrigendum on Maars to calderas: end-members on a spectrum of explosive volcanic depressions by Palladino, D. M., Valentine, G. A., Sottili, G., and Taddeucci, J. (2015). Front. Earth Sci. 3:36. doi: 10.3389/feart.2015.00036 Reason for Corrigendum: In the original article (Palladino et al., 2015), there was an error in Figure 1. The vertical axis of the qualitative plot reported erroneously “ratio of juvenile to lithic materials in deposits outside of depression”. The correct wording is as follows: “ratio of juvenile to total (i.e., juvenile+lithic) materials in deposits outside of depression”. In fact, as it was reported correctly in the text, the amount of juvenilematerial (i.e., scoria or pumice) deposited ouside the different types of explosive volcanic depressions increases from zero (i.e., no juvenile, all lithic products), as is the case of hydrothermal (phreatic) explosion craters, to become largely dominant over the lithic component in the case of ash flow deposits associated with large overpressure collapse calderas. The corrected Figure 1 appears below. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way

Wireless, in-vessel neutron monitor for initial core-loading of advanced breeder reactors

An experimental wireless, in-vessel neutron monitor was developed to measure the reactivity of an advanced breeder reactor as the core is loaded for the first time to preclude an accidental critically incident. The environment is liquid sodium at a temperature of approx. 220 C, with negligible gamma or neutron radiation. With ultrasonic transmission of neutron data, no fundamental limitation was observed after tests at 230 C for 2000 h. The neutron sensitivity was approx. 1 count/s-nv, and the potential data transmission rate was approx. 10,000 counts/s

Magneto-optical studies of photoexcitations in C61

Journal ArticleWe have used a variety of cw optical and optically detected magnetic-resonance techniques to characterize long-lived photoexeitations in methanofullerene (C6 1) as a dispersion in polystyrene glass, at temperatures below 10 K. We identify triplet excitons with zero-field-splitting (ZFS) parameters D = 105 X 10-4 cm -1 and E = 9X10-4 cm-1 . The triplet excitons are characterized by two photoinduced absorption (PA) bands in the triplet manifold at 1.5 and 1.7 eV, both with a lifetime of 160 µsec, and a phosphorescence emission (PL) band with onset at 1.85 eV and a lifetime of 10 µsec. The difference in lifetimes between PA and PL is explained as being due to different recombination kinetics of the triplet sublevels. This and the finite axial symmetry ZFS parameter E=0 compared to E=0 for triplets in C 6 0 show the lower symmetry of triplets in C6 1 , consistent with its postulated distortions from icosahedral symmetry in the ground-state structure

Optical probes of excited states in poly (p-phenylenevinylene)

Journal ArticleWe have studied electronic excited states in films of poly(p-phenylenevinylene) using picosecond transient and cw photomodulation, photoluminescence, and their excitation spectra, as well as electroabsorption spectroscopy. We have determined all the important energy levels of singlet excitons with odd and even parity, the onset of the continuum band, the two-electron (biexciton) states, and the two relevant triplet states, and show that good agreement exists with models involving electron correlation

Leng et al. reply

Journal ArticleConwell, Rothberg, and Mizes (CRM) claim [1] that, as a result of chain length distribution and vibronic sidebands of electronic levels in PPV films, there is little correlation between increase of pump photon energy (Hw) and increase of electronic energy, and therefore data from excitation spectroscopies such as those given in [2] cannot be used to study the electronic band structure of the polymers. Short chains and vibronic side band effects certainly broaden sharp spectroscopic features [3], but we disagree that these effects obscure spectroscopic data in "real samples.

Observation of molecular vibrations in real time

Journal ArticleIn a recent Letter Rosker, Wise, and Tang1 have reported ultrafast optical measurements on two large dye molecules, malachite green and nile blue 690. Using the transmission-correlation technique with 40-fs light pulses, they measured photoinduced changes in optical transmission and found a response consisting of damped oscillations superimposed on two exponential decays. They tentatively interpreted the oscillations as quantum beats between two eigenstates of the isolated molecule. In this Comment we report Raman and infrared measurements on the same molecules and discuss the implications these measurements have for the interpretation of the data of Rosker, Wise, and Tang

Cost-effectiveness of pioglitazone in type 2 diabetes patients with a history of macrovascular disease: a German perspective

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