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131.
Yomi?WatanabeEmail author Praphan?Pinsirodom Toshihiro?Nagao Takashi?Kobayashi Yutaka?Nishida Yoshiaki?Takagi Yuji?Shimada 《Journal of the American Oil Chemists' Society》2005,82(11):825-831
Acid oil is a by-product in the neutralization step of vegetable oil refining and is an alternative source of biodiesel fuel.
A model substrate of acid oil, which is composed of TAG and FFA, was used in experiments on the conversion to FAME by immobilized
Candida antarctica lipase. FFA in the mixture of TAG/FFA were efficiently esterified with methanol (MeOH), but the water generated by the esterification
significantly inhibited methanolysis of TAG. We thus attempted to convert a mixture of TAG/FFA to FAME by a two-step process
comprising methyl esterification of FFA and methanolysis of TAG by immobilized C. antarctica lipase. The first reaction was conducted at 30°C in a mixture of TAG/FFA (1∶1, wt/wt) and 10 wt% MeOH using 0.5 wt% immobilized
lipase, resulting in efficient esterification of FFA. The reaction mixture after 24 h was composed of 49.1 wt% TAG, 1.3 wt%
FFA, 49.1 wt% FAME, and negligible amounts of DAG and MAG (<0.5 wt%). The reaction mixture was then dehydrated and used as
a substrate for the second reaction, which was conducted at 30°C in a solution of the dehydrated mixture and 5.5 wt% MeOH
using 6 wt% immobilized lipase. The activity of the lipase increased gradually when the reaction was repeated by transferring
the enzyme to a fresh substrate mixture. The activity reached a maximum after 6 cycles, and the content of FAME achieved was
>98.5 wt% after a 24-h reaction. The immobilized lipase was very stable in the first-and second-step reactions and could be
used for >100 d without significant loss of activity. 相似文献
132.
Owing to the unique mechanisms operative in plasma polymerization, a thin layer of plasma polymer deposited on the surface of a substrate shows a tendency to expand, indicating an internal stress in the layer. This stress, σs, has been estimated from the observed curling of composite membranes in which the thickness of the plasma coating, d, is much smaller than the thickness of a flexible substrate, D, according to the relation where R is the radius of the roll into which the composite films curl up and E is the modulus of the substrate polymer. The stress σs is found to depend on the kind of monomer used and to be of the order of magnitude 108–109 dynes/cm2 with most of the monomers here employed. 相似文献
133.
Yuji Shimada Akio Sugihara Kazuaki Maruyama Toshihiro Nagao Suguru Nakayama Hirofumi Nakano Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1995,72(11):1323-1327
Three lipases, isolated previously in our laboratory, and a known lipase fromCandida cylindracea were screened for the enrichment of arachidonic acid (AA). The enzyme fromC. cylindracea was the most effective for the production of oil with high concentration of AA. When a single-cell oil fromMortierella alpina, containing 25% AA, was hydrolyzed with this lipase for 16 h at 35°C, the resulting glycerides contained 50% AA at 52% hydrolysis.
After this, no further hydrolysis occurred, even with additional lipase. However, when the glycerides were extracted from
the hydrolyzate and were hydrolyzed again with new lipase, the resulting oil contained 60% AA, with a recovery of 75% of its
initial AA content. Triglycerides were the main components of the resulting oil. The release of each fatty acid from the oil
depended on the hydrolysis rate of its ester. The fatty acid, whose ester is the poorest substrate for the enzyme, is concentrated
in the glycerides. 相似文献
134.
Toshihiro Ogino Toshiyuki Mitachi Kok Hooi Chan Hiroshi Oikawa Masaki Tsushima 《Soils and Foundations》2008,48(2):287-295
An experimental technique for reconstructing the received wave of bender element tests based on linear system theory is shown in this paper. In order to identify the frequency response of testing apparatus, bender element tests using frequency-swept signals are performed. Received waves for one-period sine pulse transmitting with various frequencies are calculated and compared with observed waves in several kinds of soil samples and testing apparatuses. The linearity of the testing system is also confirmed by coherence function. It is shown that calculated data are less affected by random noise and show good agreement with observed data in regards to not only waveform itself but also resulting shear wave velocity. It is mentioned that this technique can provide simulations for arbitrary transmitted waveform with high signal/noise ratio after laboratory tests are performed. It is also mentioned that this technique is advantageous when sufficient amplitude of received wave cannot be ensured or shear wave velocity must be verified, for example, due to uncertainty of arrival time by near-field effect. 相似文献
135.
Kasai Y Kodama Y Takahata Y Hoaki T Watanabe K 《Environmental science & technology》2007,41(17):6222-6227
Azoarcus sp. strain DN11 is a denitrifying bacterium capable of benzene degradation under anaerobic conditions. The present study evaluated strain DN11 for its application to bioaugmentation of benzene-contaminated underground aquifers. Strain DN11 could grow on benzene, toluene, m-xylene, and benzoate as the sole carbon and energy sources under nitrate-reducing conditions, although o- and p-xylenes were transformed in the presence of toluene. Phenol was not utilized under anaerobic conditions. Kinetic analysis of anaerobic benzene degradation estimated its apparent affinity and inhibition constants to be 0.82 and 11 microM, respectively. Benzene-contaminated groundwater taken from a former coal-distillation plant site was anaerobically incubated in laboratory bottles and supplemented with either inorganic nutrients (nitrogen, phosphorus, and nitrate) alone, or the nutrients plus strain DN11, showing that benzene was significantly degraded only when DN11 was introduced. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments, and quantitative PCR revealed that DN11 decreased after benzene was degraded. Following the decrease in DN11 16S rRNA gene fragments corresponding to bacteria related to Owenweeksia hongkongensis and Pelotomaculum isophthalicum, appeared as strong bands, suggesting possible metabolic interactions in anaerobic benzene degradation. Results suggest that DN11 is potentially useful for degrading benzene that contaminates underground aquifers at relatively low concentrations. 相似文献
136.
Sashihara T Sueki N Furuichi K Ikegami S 《International journal of food microbiology》2007,120(3):274-281
Lactobacillus gasseri OLL2809, a probiotic lactic acid bacterium, strongly stimulates interleukin (IL)-12 (p70) production by murine splenocytes; therefore, it is expected to ameliorate allergic diseases. Although many studies have investigated characteristics of the immunostimulatory activity of probiotics, little is known about how bacterial growth conditions affect the activity. In this study, we investigated the effects of the growth conditions of L. gasseri OLL2809 on the stimulation of IL-12 (p70) production. L. gasseri OLL2809 was grown under various culture conditions including different cultivation periods, media, and culture pH, and IL-12 (p70) production by murine splenocytes stimulated with these bacterial cells was determined. The results revealed that IL-12 (p70) production (i) increased with the growth of the bacterial cells and was higher in stationary-phase cells than in logarithmic-phase cells; (ii) it was higher in the cells grown in acidic pH; and (iii) it decreased when the cells were incubated in a buffer at neutral pH prior to heat treatment. These observations indicated that stimulation of IL-12 (p70) production is affected by culture medium pH. In addition, the observations of a difference in the stimulation of IL-12 (p70) production by L. gasseri OLL2809 grown under various conditions are consistent with the characteristics of autolysis. Therefore, it was deduced that the integrity of the bacterial cells is necessary for the stimulatory effect on IL-12 (p70) production and that acidic pH and heat treatment contributed to the stimulation by inhibiting the activity of autolysins indigenous to the bacteria. Our result suggests that cultivation until the stationary phase under acidic pH is required for the effective production of probiotics with immunostimulatory activity. 相似文献
137.
Katsunari Oikawa Toshihiro Omori Yuji Sutou Haruhiko Morito Ryosuke Kainuma Kiyohito Ishida 《Metallurgical and Materials Transactions A》2007,38(4):767-776
Phase equilibria and martensitic and magnetic transitions of the β (B2 and L21) phase in the Ni–Fe–Ga system were investigated. The b phase was found to be in equilibrium with the γ (A1 structure) or
γ′ (L12 structure) phase. The Curie temperature, T
c
, equilibrium temperature, T
o
5 (Ms + Af)/2, martensitic transition starting temperature, M
s
, and reverse transition finishing temperature, Af , of the β single–phase alloys were sensitive to the Fe and Ga compositions.
The Fe substitution for Ni decreased and increased the T
o
and T
c
, respectively. The Ga substitution for Ni or Fe decreased both the T
o
and T
c
. The entropy change accompanying the reverse martensitic transition showed compositional dependence due to the magnetic contribution.
The saturation magnetization I
s
of the Ni–Fe–Ga system showed a strong dependence on the magnetic valence Z
M
. The Is values of the Ni–Fe–Ga alloys annealed at 1023 K showed the same Z
m
dependence as other ferromagnetic shape memory alloy (FSMA) systems.
This article is based on a presentation made in the symposium entitled "Phase Transformations in Magnetic Materials," which
occurred during the TMS Annual Meeting, March 12-16, 2006, in San Antonio, Texas, under the auspices of the Joint TMS–MPMD
and ASMI–MSCTS Phase Transformations Committee. 相似文献
138.
In order to get useful information from various kinds of information sources, we first apply a searching process with query
statements to retrieve candidate data objects (called a hunting process in this paper) and then apply a browsing process to
check the properties of each object in detail by visualizing candidates. In traditional information retrieval systems, the
hunting process determines the quality of the result, since there are only a few candidates left for the browsing process.
In order to retrieve data from widely distributed digital libraries, the browsing process becomes very important, since the
properties of data sources are not known in advance. After getting data from various information sources, a user checks the
properties of data in detail using the browsing process. The result can be used to improve the hunting process or for selecting
more appropriate visualization parameters. Visualization relationships among data are very important, but will become too
time-consuming if the amount of data in the candidate set is large, for example, over one hundred objects. One of the important
problems in handling information retrieval from a digital library is to create efficient and powerful visualization mechanisms
for the browsing process. One promising way to solve the visualization problem is to map each candidate data object into a
location in three-dimensional (3D) space using a proper distance definition. In this paper, we will introduce the functions
and organization of a system having a browsing navigator to achieve an efficient browsing process in 3D information search
space. This browsing navigator has the following major functions: ?1. Selection of features which determine the distance for
visualization, in order to generate a uniform distribution of candidate data objects in the resulting space. ?2. Calculation
of the location of the data objects in 2D space using the selected features. ?3. Construction of 3D browsing space by combining
2D spaces, in order to find the required data objects easily. ?4. Generation of the oblique views of 3D browsing space and
data objects by reducing the overlap of data objects in order to make navigation easy for the user in 3D space. ?Examples
of this browsing navigator applied to book data are shown.
Received: 15 December 1997 / Revised: June 1999 相似文献
139.
Toshiya Sugimoto Toshihiro Koremoto Takeshi Inoue Ryoji Nomura Toshio Masuda 《Polymer Bulletin》1999,42(1):55-60
Summary
Poly(phenylacetylene)s bearing dialkylamino groups were prepared by the polymerization of p-(N,N-dialkylamino)phenylacetylenes with [Rh(nbd)Cl]2, and their electrochemical behavior was examined. Rh-catalyzed polymerization of p-(N,N-diethylamino)phenylacetylene (DEAPA) and p-(N,N-di-n-butylamino)phenylacetylene (DBAPA) in toluene in the presence of triethylamine gave good yields of the polymers (86 and 90%,
respectively). Poly(DEAPA) was soluble in chloroform and dichloromethane, and poly(DBAPA) dissolved in various solvents such
as toluene, THF, dichloromethane and chloroform. Poly(DEAPA) and poly(DBAPA) showed onset temperatures at 248 and 190°C, respectively,
and absorptions around 300–400 nm. Electrochemical doping of the polymer films resulted in the shift of the absorptions to
a region around 680 nm, which accompanied a color change of the polymer films from green ocher to deep blue.
Received: 26 October 1998/Revised version: 6 November 1998/Accepted: 12 November 1998 相似文献
140.
Makoto Yamaguchi Shoichi Shichimiya Shinji Ishibe Naomi Furuse Masahiro Kobayashi Toshihiro Suzuki Junichi Shimizu Susumu Nishiki 《Electrical Engineering in Japan》2000,131(3):34-42
New zinc oxide elements with a varistor voltage about twice that of conventional ones have been developed by reducing the ZnO grain size with a new additive, making it possible to halve the series number of elements in metal oxide surge arresters. The advanced arresters with these elements for GIS are smaller in volume by 40 to 60% compared with conventional ones. These advanced MOAs increase the flexibility in positioning MOAs and optimizing the GIS layout. This paper describes the performance of the new elements, the specification and construction of the advanced MOAs, and the results of typical evaluation tests. © 2000 Scripta Technica, Electr Eng Jpn, 131(3): 34–42, 2000 相似文献