Impact of NOx reduction on long-term ozone trends in an urban atmosphere

We investigated the relationships between ambient O(3) concentrations and the concentrations of its precursors, NO(x) and NMHC, in Osaka, Japan. The levels of O(x)' (where [O(x)']=[O(3)]+[NO(2)]-0.1x[NO(x)] where the last term accounts for primary emissions of NO(2)) were uniform within the city even in the photochemically active season. We suggested that NO oxidation by peroxy radicals was a minor contributor, and that oxidation of locally emitted NO by background O(3) in the city was the primary control on NO(2) concentrations. Ozone concentrations increased linearly from 1985 to 2002 at a rate of 0.6 ppbv/yr, even though O(x)' concentrations remained constant after the mid 1990s. The trend for O(x)' concentrations could not be explained in terms of an increase in local O(3) production, and the trend was found to reflect background O(3) concentrations in Japan. There was a clear relationship between the NO(2)/O(x)' ratio and NO(x) concentration: the ratio decreased with decreasing NO(x) concentration. As a consequence, O(3) increased with decreasing NO(x) concentration. The reduction of NO(x) emissions was deemed to be an important factor for the recent trend of increasing O(3) concentrations in Osaka City.     

基于激光莫尔信号精密定位装置的精度提高

为提高基于激光莫尔信号精密装置的定位精度 ,本文探讨了激光束束径与激光莫尔信号的依存关系 ,给出了与光栅衍射缝隙条数相对应的最小激光束束径的大小。其次还说明了激光源的光强度变化对精密定位装置的定位精度影响     

Error analysis of drill point geometry inspection using radial-view silhouette images

The conical ground drill point geometry can be described by five parameters, which are measured with the simple inspection method using radial-view silhouette images. This paper deals with error analysis of the inspection method. Different types of errors may occur while taking radial-view silhouette images of the drill point geometry. All possible setup errors have been considered and deviations from the true values of the geometrical parameters have been calculated. The sensitivities of the geometrical parameters and common angular parameters of the drill with the errors have been analyzed to develop a practical apparatus of the inspection system.     

Enzyme-assisted aqueous extraction of fat from kernels of the shea tree,Butyrospermum parkii

Chemical characteristics of kernels of the shea tree (Butyrospermum parkii) from Ghana were determined in order to design and evaluate studies on a traditional enzyme-assisted fat extraction of the kernels. The effectiveness of a number of cellular degrading enzymes in assisting the shea fat extraction were also tested by treating meals of the kernels with one or more of these enzymes before extraction and comparing the yield with control extractions. Proximate composition of the kernel on dry-matter basis was: total lipids, 59.04%; crude fat, 54.85; protein, 7.81%; total carbohydrates, 34.77%; ash, 2.57%. Starch content was 7.59%; hemicellulose, 10.84%; cellulose, 5.95%; and pectic substances, 2.93%. Total fiber content was 20.35%. The fat extracted by the Soxhlet method was pale-yellow in color and solid at room temperatures. Its physicochemical characteristics were: melting range, 34–36°C; iodine value, 58.53; saponification value, 180.37; and unsaponifiable matter content, 7.48%. The predominant fatty acids were: palmitic (3.55%), stearic (44.44%), oleic (42.41%), linoleic (5.88%) and linolenic (1.66%) acids. The enzyme-assisted extraction tests showed increases in extraction yield when the shea kernel meals were treated with the enzyme(s) before extraction. An increase of about 20% was realized when a protease and an enzyme with both cellulase and hemicellulase activities were used together. These observations confirmed the fact that the shea kernel is a rich source of fat. They also indicate the possibility of improving shea kernel extraction processes by pretreating the kernel meal with cell structure-degrading enzymes.     

Comparative study on rebound resilience and structures of sodium salts of maleic anhydride-grafted ethylene-co-ethyl acrylates with its analogous polymers

Sodium salts of ethylene-co-ethyl acrylate-g-maleic anhydride show high rebound resilience, the same as those of both saponified ethylene-co-ethyl acrylates and sodium salts of ethylene-co-methacrylic acids at low salt contents. The measurements of thermal and mechanical properties and dynamic viscoelastic behaviors indicate that the sodium salts of ethylene-co-ethyl acrylate-g-maleic anhydride behave like strong ionic bond cross-linkages close to covalent bond cross-linkages in the polymer, differing from the monocarboxylate salts of saponified ethylene-co-ethyl acrylate and the sodium salts of ethylene–methacrylic acid. It is concluded that the strong cross-linking of the dicarboxylate salts of the neutralized ethylene-co-ethyl acrylate-g-maleic anhydride causes the high rebound resilience. © 1994 John Wiley & Sons, Inc.     

High weissenberg number simulation of an annular extrudate swell using the differential type constitutive equation

Annular extrudate swell simulations at high Weissenberg numbers were made using a differential type constitutive equation. The streamline-upwinding method with a sub-element for extra stress components, which is called SU4 × 4, is one of the best mixed finite element methods for computation of viscoelastic flows. Planar and capillary extrudate swell calculations at high Weissenberg numbers (We > 1000) were accomplished by SU4 × 4. However, annular extrudate swell simulations at high We by SU4 × 4 were not successful. The calculated We was less than about 4. A new calculation technique using a Newton-Raphson discretization of the equation of motion was developed. This technique is called a “new under-relaxation method.” The calculated We of annular extrudate swell simulation by the new under-relaxation method with SU4 × 4 was about 6～250 times larger than those by SU4 × 4. Reasonable calculation results were obtained in an annular flow and a capillary extrudate swell by this method, and the reliability and the utility of the new under-relaxation method are shown. It is now possible to consider the swell shapes of annular extrudate under industrially useful conditions. The calculated swelling ratios were also compared with experimental ones.     

Direct Observation of the Double Schottky Barrier in Niobium-Doped Barium Titanate by the Charge-Collection Current Method

Charge-collection (CC) current was measured at a single grain boundary, which exhibited positive temperature coefficient of resistivity (PTCR) effects, in 0.1-mol%-Nb-doped BaTiO₃. The CC current systematically reversed across the grain boundary above the Curie point, which indicated the presence of a double Schottky barrier (DSB) at the grain boundary. In contrast, the CC current was constant across the grain boundary below the Curie temperature. The result obtained from the CC current measurement agrees with the classical DSB model in donor-doped BaTiO₃, indicating the PTCR effects.     

Oxidation kinetics of linoleic acid in the presence of saturated acyl <Emphasis Type="SmallCaps">l</Emphasis>-ascorbate

The oxidation processes of linoleic acid (LA) in the presence of l-ascorbic acid or saturated acyl l-ascorbate additives were measured at various temperatures and molar ratios of the additive to LA. Higher oxidative stability of LA was observed at higher additive levels for all additives. The addition of the ascorbates lengthened the induction period for the oxidation of LA. An autocatalytic kinetic rate equation was used to model the oxidation processes of LA mixed with the ascorbates, and the dependence of the rate constant, k, on acyl-chain carbon number was determined. At any temperature, the use of ascorbate additives decreased the k value for LA, and there was a slight tendency for k values to decrease with increasing acyl-chain length. The apparent activation energy, E _a, and the frequency factor, k ₀, for the rate constant were determined from Arrhenius plots. The calculated E _a and k ₀ values also decreased with increasing ascorbate acyl-chain length.     

Effects of microwave treatment on the oxidative stability of peanut (Arachis hypogaea) oils and the molecular species of their triacylglycerols

Peanut seeds (Arachis hypogaea) were roasted for 6, 12, 20, or 30 min at a frequency of 2450 MHz using a microwave oven. The quality characteristics and the compositions of the oils, i.e. their tocopherol distributions and the molecular species of the triacylglycerols (TAGs) were investigated. These results were compared with those of an unroasted oil sample. Only minor increases (p <0.05) in chemical and physical properties of the oils, such as the carbonyl value, the p‐anisidine value and the color development occurred after a prolonged roasting period. Compared to the original level, more than 92 wt‐% tocopherols remained after 30 min of roasting. A modified thin‐layer chromatography argentation procedure provided 12 different groups of TAGs, based on both the degrees of unsaturation and the total fatty acid chain‐length. Although significant increases (p <0.05) generated in these chemical and physical changes of the oils after 20 min of roasting, no significant loss (p >0.05) was observed in the molecular species of the TAGs during microwave roasting. These results indicate that phospholipids may be attributed to the quality characteristics of peanut oils during microwave roasting.     

Development of a Highly Sensitive β-Glucan Detection System Using Scanning Single-Molecule Counting Method

To overcome the limitations of the Limulus amebocyte lysate (LAL) assay method for the diagnosis of invasive fungal infection, we applied a reaction system combining recombinant β-glucan binding proteins and a scanning single-molecule counting (SSMC) method. A novel (1→3)-β-D-glucan recognition protein (S-BGRP) and a (1→6)-β-glucanase mutant protein were prepared and tested for the binding of (1→6)-branched (1→3)-β-D-glucan from fungi. S-BGRP and (1→6)-β-glucanase mutant proteins reacted with β-glucan from Candida and Aspergillus spp. Although LAL cross-reacted with plant-derived β-glucans, the new detection system using the SSMC method showed low sensitivity to plant (1→3)-β-D-glucan, which significantly improved the appearance of false positives, a recognized problem with the LAL method. Measurement of β-glucan levels by the SSMC method using recombinant β-glucan-binding proteins may be useful for the diagnosis of fungal infections. This study shows that this detection system could be a new alternative diagnostic method to the LAL method.