Production of gamma-lactones by the brown-rot basidiomycete Piptoporus soloniensis

A wild strain of brown-rot basidiomycete Piptoporus soloniensis produced a sweet flavor similar to tropical fruits in liquid cultures. The major and minor compounds were identified to be gamma-decalactone and gamma-octanolactone by gas chromatography-mass spectrometry analysis, respectively. The growth and production of gamma-decalactone by P. soloniensis in broth to which fatty acids had been added were investigated. The addition of 12-hydroxystearic acid and ricinoleic acid to the culture markedly enhanced the production of gamma-decalactone. On the other hand, addition of myristic acid, palmitic acid, stearic acid and oleic acid to the culture resulted in a higher production of gamma-octanolactone. The addition of hexanoic acid, octanoic acid, decanoic acid, lauric acid, linoleic acid and linolenic acid to the culture reduced the growth of P. soloniensis and production of gamma-decalactone and gamma-octanolactone. This strain accumulated oxalic acid in liquid culture and grew sufficiently under strongly acidic conditions.     

Identification of Conjugated Pentadecadienals as Sex Pheromone Components of the Sphingid Moth, Dolbina tancrei

Homologs of bombykal, (10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth, Dolbina tancrei. Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kováts retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of D. tancrei are (9E,11Z)-9,11-pentadecadienal and (9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species.     

Compact and tunable mid-infrared laser using QPM-LN waveguide and TLA

A compact and tunable difference frequency generation mid-infrared laser for gas sensing is developed using a quasi-phase-matched LiNbO₃ (QPM-LN) waveguide and a tunable laser diode array (TLA). The absorption spectra of methane from the -third- to -fifth-order around 3.3 mum are observed by tuning the QPM-LN waveguide temperature and the TLA wavelength. The absorption line width is investigated with high spectral resolution scanning and the result is compared with that calculated from the HITRAN database.     

热氧老化对丁苯胶乳体系分散稳定性的影响

研究热氧老化对丁苯胶乳体系分散稳定性的影响。结果表明,老化过程中非离子表面活性剂氧化分解产生的羧酸导致了体系pH值的下降,使胶乳粒子表面电荷总量减少,削弱了粒子间的静电斥力;同时非离子表面活性剂的分解削弱了其提供的空间位阻效应,两种因素共同影响使丁苯胶乳的分散稳定性下降。     

Reliability/performance evaluation for a multisystem with preventive maintenance

In general, a computing system with high reliability can be achieved by redundancy and/or maintenance. The sophisticated maintenance techniques are more and more important since a computing system can be operated by applying remote maintenance. In this paper we discuss a multisystem with preventive maintenance, which is one of the fault-tolerant computing systems. Making the suitable assumptions, we construct a stochastic model of such a computing system for evaluating reliability/performance. Applying Markov renewal and queueing theories, we analytically obtain several reliability/performance measures. Calculating such measures numerically, we show the impacts of preventive maintenance on such a computing system.     

Synthesis and Characterization of 2,13- and 3,13-Octadecadienals for the Identification of the Sex Pheromone Secreted by a Clearwing Moth

In addition to 2,13- and 3,13-octadecadien-1-ols and their acetates, aldehyde analogs have been identified from lepidopteran species in the family Sesiidae. To establish a reliable analytical method for determining the positions and configurations of the two double bonds in natural pheromone components, all geometric isomers of the 2,13- and 3,13-octadecadienals were synthesized by Dess-Martin oxidation of the corresponding alcohols with limited isomerization of the double bond at the 2- or 3-position. GC-MS analysis of these aldehydes showed isomerization of (Z)-2-, (Z)-3-, and (E)-3-double bonds to an (E)-2-double bond, even with a cool on-column injection. In contrast, HPLC analysis with an ODS column was accomplished without isomerization. The geometric isomers of each dienal eluted in the order ZZ → EZ → ZE → EE. The conjugated 2,13-dienals were detectable in nanogram amounts with a UV detector at 235 nm. Whereas the detection of 3,13-dienals was difficult because of the lack of a chromophore, a highly sensitive analysis was achieved after derivatization with 2,4-dinitrophenylhydrazine. LC-MS with atmospheric pressure chemical ionization showed a strong [M-1]^- at m/z 443 for the derivatives. Based on these analytical data, a pheromone extract of a sesiid moth, Macroscelesia japona, was examined by HPLC and LC-MS, and it was confirmed that the octadecadienal tentatively identified by a previous GC-MS analysis did indeed have the 2E,13Z configuration. Furthermore, field evaluation of four synthetic geometric isomers of the 2,13-dienal revealed specific attraction to a lure with the (2E,13Z)-isomer as a main component.     

Identification of Novel C20 and C22 Trienoic Acids from Arctiid and Geometrid Female Moths that Produce Polyenyl Type II Sex Pheromone Components

Gas chromatography-mass spectrometry (GC-MS) and GC-electroantennographic detection (EAD) analyses of the sex pheromone extract from a wasp moth, Syntomoides imaon (Lepidoptera: Arctiidae: Syntominae), showed that virgin females produced (Z,Z,Z)-3,6,9-henicosatriene and (Z,Z,Z)-1,3,6,9-henicosatetraene with a trace amount of their C(20) analogs. Identification of the chemical structures was facilitated by comparison with authentic standards and the double-bond positions were confirmed by dimethyl disulfide derivatization of monoenes produced by a diimide reduction. In a field test in the Yonaguni-jima Islands, males of the diurnal species were captured in traps baited with a 1:2 mixture of the above-described synthetic C(21) polyenes. Lipids were extracted from the abdominal integument and its associated oenocytes and peripheral fat bodies. Following derivatization, fatty acid methyl esters (FAMEs) were fractionated by HPLC equipped with an ODS column, and methyl (Z,Z,Z)-11,14,17-icosatrienoate and (Z,Z,Z)-13,16,19-docosatrienoate were identified by GC-MS. These novel C(20) and C(22) acid moieties are longer-chain analogs of linolenic acid, (Z,Z,Z)-9,12,15-octadecatrienoic acid. They are presumed to be biosynthetic precursors of the S. imaon pheromone because the C(21) trienyl component might be formed by decarboxylation of the C(22) acid. On the other hand, the C(20) acid, but not the C(22) acid, was found in FAMEs of Ascotis selenaria cretacea (Lepidoptera: Geometridae), which secretes C(19) pheromone components, (Z,Z,Z)-3,6,9-nonadecatriene and the monoepoxy derivative, indicating that different systems of the chain elongation might play an important role in developing species-specific communication systems mediated with polyunsaturated hydrocarbons and/or epoxy derivatives, components of Type II lepidopteran sex pheromones.     

Isomerization of n-butane by sulfated zirconia: the effect of calcination temperature and characterization of its surface acidity

The distributions of Brønsted and Lewis acid sites of different acid strengths on sulfated zirconia calcined at 450–650°C were measured by IR of adsorbed pyridine to elucidate the active sites for butane isomerization. The total numbers of Brønsted acid sites were largest when the catalyst was calcined at 500°C. The total numbers of Lewis acid sites increased with increasing calcination temperature to a maximum at 650°C. The catalytic activity in skeletal isomerization of butane correlated well with the number of Brønsted acid sites but not with the number of Lewis acid sites. The active sites were completely blocked by pyridine irreversibly absorbed at 350°C. We suggest that the strong Brønsted acid sites, which are able to retain pyridine against evacuation at 350°C, act as active sites for butane isomerization on sulfated zirconia.     

The structures of attractors reconstructed with time–evolution data of average heat transfer on thermal convection field in a vibrating square enclosure

In this paper the time‐dependent characteristics of surface‐averaged Nusselt number in a square enclosure with hot and cold side walls exposed to vertical vibrations were numerically examined. In the computation, the Prandtl number, the Rayleigh number, and the vibration Grashof number were held constant at 0.71, 10⁴, and 10⁶, respectively. The angular frequency of vibration was changed in the range between 10 and 7680. The results showed that the change in the characteristics of the surface‐averaged Nusselt number proposed by Fu and Shieh corresponded to the change in the shape of reconstructed attractor and that these regions could also be characterized by the three indices defined in phase space: average location of trajectory, the largest Lyapunov exponent, and the correlation dimension. Moreover, the time scale with which the autocorrelated coefficient of the surface‐averaged Nusselt number becomes 1/e was found to be a very important parameter for the time‐ and surface‐averaged Nusselt number. © 2000 Scripta Technica, Heat Trans Asian Res, 30(1): 11–21, 2001     

Anion-exchange properties of nickel–aluminum layered double hydroxide prepared by liquid phase deposition

The optimum coordination structure of Ni–fluoro complexes for the preparation of Ni–Al LDH by LPD process and the diverse anion-exchange properties of as-deposited Ni–Al on α-alumina powder were quantitatively evaluated for the industrial application of new positive material for alkali secondary batteries. The [NiF_6−x−y(NH₃)_x(OH⁻)_y]ⁿ⁺ was more suitable than [NiF₆]⁴⁻ as the precursor of the deposition of Ni–Al LDH in the LPD reaction, and the improved LPD reaction achieved the synthesis of high purity and high crystallinity Ni–Al LDH. All anion-exchanged Ni–Al LDHs for OH⁻–, Cl⁻–, SO₄²⁻–, and CH₃COO⁻–forms kept the high crystallinity and showed the enlargement of interlayer distances. The tilting angle of the intercalated CH₃COO⁻ anions was about 15°. Anion-exchange capacity remained constant at a minimum of 0.8 meq g⁻¹ in pH >10, increased as pH decreased, and reached a maximum of 8 meq g⁻¹ at pH 2. Anion-exchange of OH⁻–form of Ni–Al LDH was accelerated by the neutralization of hydroxide ions in interlayers, in addition, the anion-exchange capacity and the crystallinity of Ni–Al LDH could be controlled by the amount of doped aluminum ions.