Sequence distribution of cis-1,4- and trans-1,4-units in polyisoprenes

The ¹³C n.m.r. spectra of chicle polyisoprene and cis-trans isomerized 1, 4-polyisoprenes were studied. The splittings of signals were observed in the C₁, C₂, and C₄ carbon signals of the isomerized polyisoprenes. The newly appearing signals were assigned to the carbon atoms in cis-trans linkages. The fractions of the diad sequences (trans-trans, trans-cis, cis-trans, and cis-cis) were determined by using the four signals of C₁ carbon. It was found that the cis-1, 4- and trans-1, 4-units were randomly distributed in the isomerized polyisoprenes and it was confirmed that the chicle polyisoprene was a mixture of cis-1, 4- and trans-1, 4-polyisoprenes.     

Miscibility in binary blends of aromatic and alicyclic polyamides

Miscibility was studied for four polyamide blends of 6I/6T [copolymer consisting of 1,6‐hexamethylene diamine and isophthalic acid (6I) (70 wt %) and terephthalic acid (6T) (30 wt %)] with MXD6 (polyamide of m‐xylenediamine and adipic acid), BAC6 (polyamide of 1,3‐bis(aminomethyl)cyclohexane and adipic acid), TR55 (copolymer consisting of nylon 11 (30 wt %), and polyamide of bis(3‐methyl, 4‐aminocyclohexyl)methane (30 wt %) and isophthalic acid (70 wt %), and CX7323 (polyamide of bis(4‐aminocyclohexyl)methane and dodecanedicarboxylic acid), using differential scanning calorimetry, X‐ray diffraction method, and electronmicroscopic observation. In quenched MXD6/(6I/6T) and BAC6/(6I/6T) blends, MXD6 and BAC6 components were miscible to 6I/6T, but TR55 and CX7323 components were completely phase‐separated from 6I/6T. Interestingly on electronmicroscopic observations, TR55 and CX7323 components were seen as droplets in 6I/6T medium when the content is low, but when 50 wt %, a layered structure was constructed with 6I/6T, reminiscent of morphological structure in block copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3971–3978, 2006     

Pilot-Scale Operation of a Concrete Sludge Recycling Plant and Simultaneous Production of Calcium Carbonate

A pilot-scale plant to treat concrete sludge and produce calcium carbonate (CaCO₃) and an environmental purification agent (phosphorus adsorbent derived from concrete sludge, PAdeCS®) was designed, constructed, and operated. Concrete sludge from a concrete pile and pole production plant, boiler gas containing CO₂, and groundwater were used in the plant. The process involved calcium extraction from concrete sludge into water, followed by reaction of the calcium with CO₂ to produce crystalline CaCO₃. The pilot-scale plant was operated for 1 week, and the mass flows, conversion of CO₂ to CaCO₃, and net CO₂ emissions of the process were estimated. High-purity CaCO₃ (>97%) suitable for industrial use was obtained. Based on the power consumption of the process and the amount of CO₂ sequestered into CaCO₃, a net reduction in CO₂ emissions can be achieved using this process. The produced PAdeCS can be used as an inexpensive substitute for calcium series environmental purification agents.     

A study on a porous residential building model in hot and humid regions: Part 1—the natural ventilation performance and the cooling load reduction effect of the building model

This study targets environmental load reduction in hot and humid regions. It reveals the effects that porous residential buildings have on the natural ventilation performance and, consequently, the cooling load reduction. Two residential building models, namely a model with a void ratio of 0% and a model with a void ratio of 50%, are evaluated using computational fluid dynamics (CFD) analysis and thermal and airflow network analysis. The analysis on components of the heat load indicates that improvements in the natural ventilation performance would significantly reduce the cooling load.     

In vivo monitoring of intravenously injected gold nanorods using near-infrared light

Gold nanorods showing surface plasmon (SP) bands in the near-IR region are used as bioimaging probes that respond to near-IR light in mice. The SP bands of intravenously injected polyethylene glycol-modified gold nanorods are directly monitored from the mouse abdomen by using a spectrophotometer equipped with an integrating sphere. The absorbance at 900 nm from the gold nanorods immediately increases after injection and reaches a plateau. The injection of phosphatidylcholine-modified gold nanorods also increases the absorbance at 900 nm, but the absorbance decreases single exponentially with a 1.3-min half-life. In vivo spectral changes of gold nanorods depend on the surface characteristics, and can be observed in real time using simple spectroscopic measurements.     

Apple polyphenols influence cholesterol metabolism in healthy subjects with relatively high body mass index

We performed a randomized double-blind, placebo-controlled study on moderately obese male and female subjects (71 subjects) with a body mass index ranging from 23 to 30 to evaluate the efficacy of 12-week intake of polyphenols extracted from apples and hop bract (600 mg/day). We confirmed that 12-week ingestion of polyphenol-containing capsules significantly decreased total cholesterol and LDL-cholesterol levels. The effects of the apple polyphenol-containing capsules were more marked than those of the hop bract polyphenol-containing capsules. The visceral fat area and the level of adiponectin in the group administered apple polyphenols improved in comparison with the control group. Blood and physical examinations revealed on clinical problems, and no adverse reactions were observed during the ingestion period. These results demonstrate that apple polyphenols regulate fat metabolism in healthy subjects with relatively high body mass index.     

Comparison of carbonaceous aerosols in Tokyo before and after implementation of diesel exhaust restrictions

We compared the status of carbonaceous aerosols in Tokyo before and after the implementation of a diesel vehicle regulation intended to reduce the quantity of particulate carbon from diesel engines in one of the largest scale ever attempts at vehicle exhaust control. Radiocarbon (14C) in elemental carbon (EC) and total carbon (TC) were analyzed to identify fossil fuel carbonaceous particles emitted from diesel-powered vehicles. One-sided paired-month t-tests showed no distinct difference in the absolute concentrations of particles in terms of total mass (19.5 to 18.0 microg m(-3); p = 0.321), EC (3.6 to 3.3 microg m(-3); p = 0.272), and TC (6.3 to 6.2 microg m(-3); p = 0.418) for the finest particles (d(a) < 1.1 microm) after the implementation of the regulation. The ratios of the concentrations of the chemical constituents were, however, altered after the regulation. EC/TC was significantly decreased from 56.7% to 50.2% (p = 0.039). Although it was not statistically significant, the percentage of fossil carbon in EC also decreased (67.8% to 63.8%; p = 0.104). Since EC is predominantly of combustion origin, the observed decrease was likely due to the decrease in fossil EC emissions from diesel-powered vehicles. The decrease in EC/TC after the implementation of the regulation was also likely to have resulted from attachment to diesel vehicle exhaust systems of particulate filters as required as part of the regulation by the Tokyo Metropolitan Government. The EC/TC of fossil carbon of the finest particles decreased from 66.2% to 55.2% (p = 0.066), but EC/TC of biomass carbon did not decrease but rose slightly from 43.6% to 44.5% (p > 0.5). Thus, the relative ratios of components of carbonaceous aerosol particles, such as 14C, could provide a better understanding of the atmospheric pollution status, despite short-term fluctuations, than do measurements of absolute concentrations.     

Selective catalytic reduction of nitrogen oxides with hydrocarbons over Zn–Al–Ga complex oxides

Selective reduction of NO with hydrocarbons was studied using metal oxide catalysts having a spinel structure. A Zn–Al–Ga complex oxide was found to be very active and selective for the catalytic reduction of NO with both C₃H₆ and CH₄. It was revealed that the role of oxygen at the initial stage of the reaction strongly depends on the reductants; oxygen is mainly used for NO oxidation to NO₂ in the reduction with CH₄, whereas it is used both for NO oxidation to NO₂ and oxidation of C₃H₆ to an active intermediate in the reduction with C₃H₆. This revised version was published online in July 2006 with corrections to the Cover Date.     

Highly elongated,low‐aspect‐ratio tokamak produced by negative‐biased theta pinch

Ultra Low Aspect Ratio Tokamaks (ULART) are produced by using a negative‐biased theta‐pinch device. A slender conducting rod which serves as a toroidal field coil is newly installed along a geometrical center axis of the theta‐pinch coil. The ULART is quickly formed for about 10 μs by applying programmed current flows from three sets of fast banks and a slow bank to these coils and is sustained for about 100 μs. The plasma diagnosed from a magnetic probe array has a low aspect ratio A = 1.1 and a poloidal surface with a high elongation ratio κ = 10. The safety factor reaches about 30 near the separatrix edge when I_p = 280 kA flows in the plasma and I_tfc = 30 kA in the conducting rod. A preliminary result on global MHD characteristics of the ULART is also given. The plasma is unstable with respect to a vertical displacement and a toroidal n = 1 mode. The amplitudes of these modes depend on the values of I_tfc and κ. © 2001 Scripta Technica, Electr Eng Jpn, 134(4): 19–27, 2001