Quantitative monitoring of the stripper foil degradation in the 3-GeV rapid cycling synchrotron of the Japan proton accelerator research complex

A hybrid-type boron doped carbon stripper foil of 200 μg/cm² is used for the present H^? injection beam energy of 181 MeV in the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC). A stripper foil has a certain lifetime and usually lifetime goes shorter for high power operation. Foil degradation such as foil thinning and pinhole formation caused by the radiation might be a signal of the foil breaking. As a result, one can avoid sudden foil breaking by an efficient monitoring of the foil degradation. We have succeeded measuring even a little change of the stripper foil thickness during user operation of the RCS. It is the main motivation of the present study. A single foil was irradiated with a total of 2.7 × 10²¹ particles (injected H^? itself) during 4 months continuous operation of the RCS but we did not observe any indication of the foil degradation.     

Concentrations of 137Cs and 40K in wild mushrooms collected in a forest on Noto Peninsula,Japan

A variety of wild mushrooms were collected in a forest on the Noto Peninsula, Japan, to determine the concentration of ¹³⁷Cs and ⁴⁰K. The wild mushroom species belong to the orders Agaricales and Aphyllophorales. The concentration of ¹³⁷Cs varied widely (1.4–4,100 Bq/kg dry weight) in mushrooms growing in soil. On the contrary, ¹³⁷Cs concentration levels were relatively low (1.9–20 Bq/kg-dry weight) in mushrooms growing on wood. The concentration of ⁴⁰K varied widely (12–2,400 Bq/kg-dry weight) in contrast with several previous reports that suggest relatively constant ⁴⁰K levels in mushrooms. Unusually low concentrations of ⁴⁰K were observed in a few mushroom species that had very hard fruiting bodies with peculiar shapes. The mean and median of ¹³⁷Cs concentration in the present study were similar to those previously reported for Japanese mushrooms. Among the Agaricales mushrooms, Entolomataceae and Tricholomataceae families growing in soil had the highest concentration of ¹³⁷Cs. Among the Aphyllophorales mushrooms, Gomphaceae and Ramariaceae families growing in soil also had the highest ¹³⁷Cs concentrations. The concentrations of ¹³⁷Cs and stable Cs in mushroom samples were positively correlated. The concentration ratio of ¹³⁷Cs/Cs differed between Agaricales and Aphyllophorales mushrooms. The average ¹³⁷Cs/Cs ratio in mushrooms growing in soil was similar to that calculated for the top soil (<5 cm deep) alone because the mycelia of the mushrooms were mainly distributed near the surface of the soil.     

Vacuum Ultraviolet and Soft X‐ray Photoelectron Spectroscopy of Liquid Beams Using a Hemispherical Photoelectron Spectrometer with a Multistage Differential Pumping System

We present photoelectron spectroscopy of liquid beams using a high‐resolution hemispherical photoelectron spectrometer with a multistage differential pumping system developed in our laboratory. Intense soft X‐ray synchrotron radiation (500‐1200 eV) at SPring‐8 and a relatively large detection solid angle (1.5 × 10^?2 π sr) of the spectrometer enable highly efficient measurements of X‐ray photoelectron spectra of liquids. Vacuum ultraviolet photoelectron spectroscopy using the same spectrometer provides sufficiently high spectral resolution to resolve rotational isomers of gas‐phase molecules.     

Enantiomerically Enriched Bicyclic Hydroxamic Acids in One Step from α-Aminohydroxamic Acids and Keto Acids via Cyclocondensation

New enantiomerically enriched bicyclic hydroxamic acids, 1-hydroxy-dihydro-1H-pyrrolo[1,2-a]imidazole-2,5(3H,6H)-diones, have been synthesized by the cyclocondensation of L-α-aminohydroxamic acids with keto acids in a highly chemo- and stereoselective manner. The cis configuration between the amino acid side chain and the methyl group at C7a in 1H-pyrrolo[1,2-a]imidazole-2,5-dione was unambiguously established by X-ray crystallographic analysis. This method could also be applied to the cyclocondensation with o-formylbenzoic acid, giving a tricyclic hydroxamic acid in a good yield.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Multiresolution potential energy surfaces for vibrational state calculations

A compact and robust many-mode expansion of potential energy surfaces (PES) is presented for anharmonic vibrations of polyatomic molecules, where the individual many-mode terms are approximated with various different resolutions, i.e., electronic structure methods, basis sets, and functional forms. As functional forms, the following three representations have been explored: numerical values on a grid, cubic spline interpolation, and a Taylor expansion. A useful index is proposed which rapidly identifies important many-mode terms that warrant a high resolution. Applications to water and formaldehyde demonstrate that the present scheme can increase the efficiency of the PES computation by a factor of up to 11 with the errors in anharmonic vibrational frequencies being no worse than ~ 10cm⁻¹.     

Enhancement of the binding ability of a ligand for nucleobase recognition by introducing a methyl group.

The recognition ability of pteridine derivatives for nucleobases opposite an abasic (AP) site in an oligodeoxynucleotide (ODN) duplex is enhanced by using a propylene residue (Spacer-C3) as an AP site. The recognition ability is further enhanced both by attaching methyl groups to a fluorescent ligand and by measuring the fluorescence response at 5 degrees C; 6.2 x 10(6) M(-1) of the binding constant is attained between 2-amino-6,7-dimethyl-4-hydroxypteridine and guanine opposite the AP site in water.     

Intramolecular energy transfer in 3-amino-N-(7′-methoxy-4′-methylcoumaryl)phthalimide

The synthesis and fluorescence property of 3-amino-N-(7′-methoxy-4′-methylcoumaryl)phthalimide (AMMP) are described. The fluorescence of AMMP originated during the intramolecular energy transfer from the coumarin moiety to the phthalimde moiety in various solvents. The ab initio quantum chemical calculation of the AMMP revealed that the HOMO and LUMO of AMMP were localized in the coumarin and phthalimide moieties, respectively.     

Diamond particles synthesized with graphite spark method in two seconds

A wide bandgap semiconductor, diamond, has recently emerged as important and promising materials for a wide field of optoelectronic and electronic applications. With graphite spark method in hydrogenic atmosphere, we successfully synthesized diamond particles in 3–5 μm diameter in only ten seconds and in 1–2 μm diameter in two seconds. The resultant particles were observed with SEM (Scanning Electron Microscope) images, and confirmed as diamond by sharp peak on 1331 cm⁻¹ with Raman spectrometer.With this study, we searched for precursors with various experimental conditions, such as hydrogen pressures and/or graphite temperatures. For gaseous species identification, OES (Optical Emission Spectroscopy) results will be reported on this presentation, and the preliminary synthesis mechanism for ‘spark method’ will be presented.     

High throughput evaluation of the production of substituted acetylenes by the Sonogashira reaction followed by the Mizoroki-Heck reaction in ionic liquids, in situ, using a novel array reactor

The parallel Sonogashira coupling reaction was carried out under copper-free condition by integrating the advantages of ionic liquids as the reaction media followed by the simultaneous-multiple Mizoroki-Heck reaction in situ by the use of a novel array reactor (SynArray-24). The device provides rapid evaluation of reactions in a short period.     

Estimation of organophosphoric acid triesters in soft polyurethane foam using a concentrated sulfuric acid dissolution technique and gas chromatography with flame photometric detection.

A concentrated sulfuric acid dissolution technique and a GC method are described for the estimation of tributyl phosphate, tris(2-chloroethyl) phosphate, tris(chloropropyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate, triphenyl phosphate and tris(butoxyethyl) phosphate in soft polyurethane foam. A soft polyurethane foam sample containing organophosphoric acid triesters was dissolved in concentrated sulfuric acid. The solution was added to water, where only the polyurethane was separated out. The pH of the solution was adjusted, and organophosphoric acid triesters were extracted with toluene. After purification, the compounds were determined by GC. The detection limits of the organophosphoric acid triesters were 0.3 - 0.9 microg g(-1). The recoveries of the organophosphoric acid triesters from a 0.05 g sample of soft polyurethane foam were 80.0 - 90.0%, when the spiked amounts were 0.25 - 1 microg. The compounds were detected from soft polyurethane foam at the level of 0.4 - 23.3 microg g(-1).