Hydrocracking of diphenylmethane

This study presents the role of H₂S other than H-transfer catalyst in the hydrocracking of diphenylmethane with H₂–H₂S-pyrrhotite. The results indicate that the partial pressure of H₂S controls the conversion of pyrrhotite to FeS and FeS₂, which in turn is closely related to the promotional activity of pyrrhotite on the diphenylmethane conversion. Under higher H₂S overpressures, pyrite bands appear in the Mössbauer spectra providing proof of the reversibility of pyrite decomposition under liquefaction conditions. With lower H₂S pressures, low activity troilite forms from the pyrrhotite. An enhanced activity was observed for a partial pressure of H₂S, sufficient for the maintenance of a high iron deficient surface on the pyrrhotite particles. When the partial pressure was increased too much, the formation of FeS₂ was observed with a slight decrease in activity. FeS did not show as great an activity as the non-stoichiometric pyrrhotite.     

Extraction of uranium (VI) from hydrochloric acid solutions by long-chain aliphatic amines

The partition of uranium (vi) between hydrochloric acid solutions and organic solutions of long-chain aliphatic amines has been investigated at different concentrations of hydrochloric acid, solvent and aqueous uranium, and at different temperatures. The effects of amine structure and of organic solvent and the mechanism of uranium extraction are discussed on the basis of the results obtained. From infra-red spectral measurements it is postulated that a chloro complex of uranium (vi) is formed in the extraction of uranium (vi) from hydrochloric acid solution by tri-n-dodecylamine in benzene.     

Hydrocracking of diphenylmethaneRoles of H2S, pyrrhotite and pyrite

This study presents the role of H₂S other than H-transfer catalyst in the hydrocracking of diphenylmethane with H₂–H₂S-pyrrhotite. The results indicate that the partial pressure of H₂S controls the conversion of pyrrhotite to FeS and FeS₂, which in turn is closely related to the promotional activity of pyrrhotite on the diphenylmethane conversion. Under higher H₂S overpressures, pyrite bands appear in the Mössbauer spectra providing proof of the reversibility of pyrite decomposition under liquefaction conditions. With lower H₂S pressures, low activity troilite forms from the pyrrhotite. An enhanced activity was observed for a partial pressure of H₂S, sufficient for the maintenance of a high iron deficient surface on the pyrrhotite particles. When the partial pressure was increased too much, the formation of FeS₂ was observed with a slight decrease in activity. FeS did not show as great an activity as the non-stoichiometric pyrrhotite.     

Carboxyl‐terminated butadiene acrylonitrile rubber/epoxy polymer alloys as damping adhesives and energy absorbable resins

Carboxyl‐terminated butadiene acrylonitrile (CTBN) liquid rubber/epoxy (diglycidyl ether of bisphenol‐A: DGEBA) / diamino diphenyl methane (DDM) resins, in which CTBN was 60 wt % as the major component, were formulated to evaluate the damping and adhesive properties. In cases where acrylonitrile (AN) was 10～18 mol % as copolymerization ratio in CTBN, the blend resins showed micro‐phase separated morphologies with rubber‐rich continuous phases and epoxy‐rich dispersed phases. The composite loss factors (η) for steel laminates, which consisted of two steel plates with a resin layer in between, depended highly on the environmental temperature and the resonant frequencies. On the other hand, in the case where AN was 26 mol % in CTBN, the cured resin did not show clear micro‐phase separation, which means the components achieve good compatibility in nano‐scale. This polymer alloy had a broad glass‐transition temperature range, which resulted in the high loss factor (η > 0.1) for the steel laminates and excellent energy absorbability as the bulk resin in a broad temperature range. Also the resin indicated high adhesive strengths to aluminum substrates under both shear and peel stress modes. The high adhesive strengths of the CTBN/epoxy polymer alloy originated in the high strength and the high strain energy to failure of the bulk resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Measuring air-water interfacial areas with X-ray microtomography and interfacial partitioning tracer tests

Air-water interfacial areas as a function of water saturation were measured for a sandy, natural porous medium using two methods, aqueous-phase interfacial partitioning tracer tests and synchrotron X-ray microtomography. In addition, interfacial areas measured in a prior study with the gas-phase interfacial partitioning tracer-test method for the same porous medium were included for comparison. For all three methods, total air-water interfacial areas increased with decreasing water saturation. The interfacial areas measured with the tracer-test methods were generally larger than those obtained from microtomography, and the disparity increased as water saturation decreased. The interfacial areas measured by microtomography extrapolated to a value (147 cm(-1)) very similar to the specific solid surface area (151 cm(-1)) calculated using the smooth-sphere assumption, indicating that the method does not characterize the area associated with microscopic surface heterogeneity (surface roughness, microporosity). This is consistent with the method resolution of approximately 12 microm. In contrast, the interfacial areas measured with the gas-phase tracer tests approached the N2/BET measured specific solid surface area (56000 cm(-1)), indicating that this method does characterize the interfacial area associated with microscopic surface heterogeneity. The largest interfacial area measured with the aqueous-phase tracer tests was 224 cm(-1), while the extrapolated maximum interfacial area was approximately 1100 cm(-1). Both of these values are larger than the smooth-sphere specific solid surface area but much smaller than the N2/BET specific solid surface area, which suggests that the method measures a limited portion of the interfacial area associated with microscopic surface heterogeneity. All three methods provide measures of total (capillary + film) interfacial area, a primary difference being that the film-associated area is a smooth-surface equivalent for the microtomography method. An advantage of the microtomography method is the ability to determine explicitly both total and capillary-associated interfacial areas, which is problematic for the tracer-test methods.     

Enhancement of the activity of renatured lysozyme by protein disulfide isomerase

The coexistence of protein disulfide isomerase (PDI) in the oxidative refolding of a fully reduced hen egg white lysozyme brought about a final recovered activity significantly exceeding 100% in addition to the expected acceleration effect. This increase could not be explained by the simple increase produced by suppressing aggregation. After examination of the starting material and assay system, it was concluded that PDI enhances the activity of renatured lysozyme.     

Quantitative Analysis of The High-Yield Hydrolysis of Kelp by Laminarinase and Alginate Lyase

Kelp is an abundant, farmable biomass-containing laminarin and alginate as major polysaccharides, providing an excellent model substrate to study their deconstruction by simple enzyme mixtures. Our previous study showed strong reactivity of the glycoside hydrolase family 55 during hydrolysis of purified laminarin, raising the question of its reactivity with intact kelp. In this study, we determined that a combination of a single glycoside hydrolase family 55 β-1,3-exoglucanase with a broad-specificity alginate lyase from the polysaccharide lyase family 18 gives efficient hydrolysis of untreated kelp to a mixture of simple sugars, that is, glucose, gentiobiose, mannitol-end glucose, and mannuronic and guluronic acids and their soluble oligomers. Quantitative assignments from nanostructure initiator mass spectrometry (NIMS) and 2D HSQC NMR spectroscopy and analysis of the reaction time-course are provided. The data suggest that binary combinations of enzymes targeted to the unique polysaccharide composition of marine biomass are sufficient to deconstruct kelp into soluble sugars for microbial fermentation.     

Monotonic and Cyclic Behavior of Unsaturated Sandy Soil Under Drained and Fully Undrained Conditions

Changes in air pressure during monotonic and cyclic loading are in some cases important for the behavior of unsaturated soil. For example, in order to investigate the stability of embankments and slope failure during earthquakes, it is necessary to consider the effect of the pore air or the pore gas pressure as well as the pore water pressure and the interaction between the soil and the pore fluids. In the present study, we carried out a series of monotonic and cyclic loading tests on sandy soil used for the improvement of river embankments. The effects of the initial suction, the confining pressure, and the degree of compaction under fully undrained conditions, namely, constant water and constant air shearing tests, as well as under drained conditions for both air and water, were studied. For the stress variables of the unsaturated soil, the skeleton stress was used to describe the experimental results and was defined as the difference between the total stress tensor and the average pore pressure of water and gas (Oka et al., 2010). From the monotonic and cyclic test results, we found that the stress-strain behavior of unsaturated sandy soil strongly depends on the initial suction, especially under fully undrained conditions, due to the difference in pore pressures. In the cyclic loading tests under fully undrained conditions, the mean skeleton stress decreased due to the increase in air pressure and led to the failure of the specimen in the case of a lower level of initial suction. In addition, the test results exhibited the strain rate effect on the stress-strain behavior during cyclic loading under fully undrained conditions.     

Occurrence of perchlorate in drinking water sources of metropolitan area in Japan

The occurrence of perchlorate in the Tone River Basin was investigated using an ion chromatograph (IC) coupled with a tandem mass spectrometer (MS/MS). Perchlorate was found at high concentrations in the upper Tone River and its tributary, Usui River, and the maximum concentrations were 340 and 2300 microg/L, respectively. The possible sources of perchlorate in two areas were attributable to industrial effluents. In case of the upper Tone River, perchlorate concentration in an effluent was 1100 microg/L and its concentrations in a tributary (or waterway) directly downstream of the outlet of the effluent ranged from 44 to 1500 microg/L. In case of the Usui River, perchlorate concentration in another effluent was 15,000 microg/L and its concentrations downstream of the outlet of the effluent were 1100-3900 microg/L. Due to the discharge of perchlorate in the upper Tone River Basin, perchlorate concentrations in the river waters of the middle and lower Tone River Basin were generally 10-20 microg/L. Perchlorate concentrations in 30 tap water samples were investigated. Water sources of three tap water samples were other than the Tone River Basin and their perchlorate concentrations were 0.16-0.87 microg/L. On the other hand, water sources of the remaining 27 samples were the upper, middle and lower Tone River Basin and their perchlorate concentrations were 0.06-37 microg/L. Perchlorate concentrations were more than 1 microg/L in 19 tap water samples and more than 10 microg/L in 13 samples. It was shown that tap waters in the Tone River Basin were widely contaminated with perchlorate. To our knowledge, this study was the first to report on perchlorate contamination of environmental and drinking waters in Japan.