• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.1
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• pp.1-9
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• 2013

This paper proposes a ST(Switched Trans) quasi Z-source inverter using a Switched Trans Cell combing the characteristics of a Switched Inductor Cell and Trans. A DC link inductor of the conventional quasi Z-source inverter is alternated with Switched Trans Cell of the proposed ST quasi Z-source inverter. Trans Cell of the proposed method consists of one Trans and two diodes, and the proposed method has higher and more various boost function than the conventional quasi Z-source inverter by simply changing the turns ratio of primary and secondary of the Trans. The validity of the proposed ST Z-source inverter was confirmed by PSIM simulation and a DSP based experiment under the input voltage 48V and output phase voltage 30V. As a result, when compared with the traditional quasi Z-source inverter, the proposed method has the advantage of the low voltage stress under the same output voltage condition of the voltage.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.307-312
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• 1993

Antioxdant effect was studied in model system with linoleic acid methylester and tocochromanols $({\alpha}-,\;{\beta}-,\;{\gamma}-,\;{\delta}-tocopherol\;and \;{\alpha}-,\;{\gamma}-,\;{\delta}-tocotrienol)$ under definite autoxidation condition-temperature $(40,\;60,\;80^{\circ}C),\;O_2\;(0,\;10,\;20%\;O_2\;in\;N_2)$. 13-Hydroperoxy-9-cis-11-trans-, 13-hydroperoxy-9-trans-11-trans-, 9-hydroperoxy-10-trans-12-cis-, 9-hydroperoxy-10-trans-12-trans-octadecadienoic acid methylester as the major oxidation product were produced from linoleic acid methylester by autoxidation, analyzed with HPLC and antioxidant activities were compared by their quantitative changes. Experimental results showed that all added tocochromanols except ${\alpha}-tocotrienol$ had antioxidant effect at $60^{\circ}C$, and also ${\alpha}-tocopherol$, ${\alpha}-tocotrienol$ and ${\delta}-tocotrienol$ had prooxidant effect at $80^{\circ}C$. And cis/trans-hydroperoxide was predominantly produced at $40^{\circ}C$, but trans/trans-hydroperoxide at $80^{\circ}C$. Except no reproductive experimental data in produced hydroperoxides amount, the production ratio of cis/trans-:trans/trans-hydroperoxides in the autoxidation condition of range from $40^{\circ}C/10%,\;O_2\;to\;60^{\circ}C/20%\;O_2$ were as follows: ${\alpha}-T>{\alpha}-T_3>{\gamma}-T>{\beta}-T>{\gamma}-T_3>{\delta}-T>{\delta}-T_3$. This result showed that ${\alpha}-tocopherol$ among tocochromanols had the lowest antioxidant effect.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.201-205
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• 2011

Although various biological activities of resveratrol have been extensively studied, most reports have focused on trans-resveratrol and little attention has been paid to the cis-isomer. In this study, the effect of cis-resveratrol on platelet activity was examined and compared with that of the trans-isomer. Treatment with cis-resveratrol resulted in inhibition of platelet aggregation induced by thrombin, collagen or ADP, which are representative aggregation-inducing agents, and the trans-isomer elicited the same effects. These effects were concentration-dependent in the range of 1-100 ${\mu}M$. However, the potency of the cis-isomer was much lower than that of the trans-isomer; the $IC_{50}$ values for the cis-isomer versus the trans-isomer were $31{\pm}12$ vs $151{\pm}3$, $161{\pm}3$ vs $91{\pm}4$, and $601{\pm}15$ vs $251{\pm}6\;{\mu}M$ for thrombin-, collagen- and ADP-induced aggregation, respectively. These results indicate that cis-resveratrol has a less potent anti-platelet activity, compared with the trans-isomer, and raise the possibility that the biological activities of the cis-isomer may be different from those of the trans-isomer. It will be necessary to evaluate the activity of cis-resveratrol independently of the trans-isomer.

• Journal of Nutrition and Health
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• v.42 no.3
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• pp.291-299
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• 2009

This study was carried out to examine the proportion of fatty acids and contents of trans fatty acid in commercial processed foods in Jeon-Buk area. Contents of trans fatty acid in bakery products ranged from 0.2% to 1.0% per 100 g food. Especially garlic bread and pastry contained the highest amount. Popcorns contained trans fatty acid from 0.0% to 13.4%. Among them, instant popcorns for microwave contained the highest amount, while trans fatty acid was hardly detected in popcorns for theater. And trans fatty acid detected in popcorns was mostly in the form of 18 : 1 trans. The content of trans fatty acid in pizza was nearly 0.2%. Amounts of saturated fatty acid and unsaturated fatty acid were similar between each type of pizza and frozen pizza. Fritters such as fried chickens and vegetables contained trans fatty acid less than 0.2% per 100 g food.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.109-117
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• 2007

Methyl trans-cinnamate is a significant flavor compound of Tricholoma matsutake. Attempts were made to produce this compound by culturing the mycelium using submerged culture. No methyl trans-cinnamate could be detected when the mycelium was cultured in the basal liquid medium. However, the addition of Pinus desiflora extracts to the medium, methyl trans-cinnamate was largely produced. To find out compounds or fractions inducing methyl trans-cinnamate, dichloromethane fraction obtained from the wood extracts of P. densiflora was subjected to column chromatography. Three sub-fractions were obtained from the $CH_2CI_2$ fraction. Submerged cultured mycelium treated with sub-fraction 1 has the highest content of methyl trans-cinnamate. Maximum methyl trans-cinnamate $(470.2{\mu}g/g)$ was obtained when the first sub-fraction of dichloromethane fraction of the P. densiflora wood extracts was added to the medium. This indicates that wood extracts of P. densiflora contains inducer of the methyl trans-cinnamate production in the T. matsutake submerged culture.

• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.3-13
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• 1984

The trans effect of ligands on the calculated dipole moments has been investigated, choosing trans square planar $[Pt(II)Cl(PEt_3)_2X]$ type complexes. The calculated dipole moments decrease in the order H > Me > Ph > Cl which is the same as the order of decreasing the experimental dipole moments. This order is in agreement with the order of decreasing the trans effect as determined by rate of reaction. The calculated dipole moments for cis complexes are markedly higher than those for trans complexes. This is also in agreement with experimental fact. The calculated dipole moments for some of cis complexes are, however, lower than the observed values, which is different from trans complexes.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.495-500
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• 1988

The trans effect has been interpreted for a series of trans-[PtNH$_3$Cl$_2$2L] (L = H$_2$O, NH$_3$, Cl$^-$, Br$^-$, I$^-$, CH$_3$ and PH$_3$) and PtCl$_4^{-2}$ by means of our modified-EHMO method. The calculation shows that reduced overlap population(ROP) of Pt-N bond trans to L is decreased with a better trans director. That is, the trans effect has been found to be enhanced with a better trans director. Accordingly, it could be interpreted quantum chemically the trans effect for a general trans-PtTL$_2$X complex.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.6-12
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• 1998

Degummed and bleached soybean oil was deodorized at a temperature range of $220{\sim}280^{\circ}C$ under the vacuum (4-5 torr) for 1 or 2 hrs. Gas chromatography with SP-2560 100 m capillary column was used to separate and quantitate fatty acid methyl esters and their isomers. Fatty acids were identified by comparing retention time with standards and GC-MS spectrum. The isomers of linoleic acid and linolenic acid in deodorized soybean oils were identified to be $C_{18:2}\;{\Delta}9-cis,\;{\Delta}12-trans,\;C_{18:2}\;{\Delta}9-trans,\;{\Delta}12-cis,\;C_{18:2}\;{\Delta}9-cis,\;{\Delta}12-cis,\;C_{18:3}\;{\Delta}9-cis,\;{\Delta}12-cis,\;{\Delta}15-trans,\;C_{18:3}\;{\Delta}9-trans,\;{\Delta}12-cis,\;{\Delta}15-cis,\;C_{18:3}\;{\Delta}9-cis,\;{\Delta}12-trans,\;{\Delta}15-cis,\;and\;C_{18:3}\;{\Delta}9-cis,\;{\Delta}12-cis,\;{\Delta}15-cis$. The formation of trans-fatty acids by deodorization at $240{\sim}280^{\circ}C$ for 2 hrs was in the range of 1.78 to 5.74%. Conclusively, the deodorizing conditions of $240^{\circ}C$ for 2 hrs or $250^{\circ}C$ for 1 hr were suggested as the best conditions which could minimize the formation of trans isomers of fatty acids in soybean oils.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1566-1573
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• 2009

Trans-10, cis-12 conjugated linoleic acid (CLA) has been reported to inhibit the adipocyte differentiation of preadipocytes in non-ruminant animals (mice, rat, and human). However, the effects of trans-10, cis-12 CLA have not been clear in ruminants. The objective of this study was to investigate the effects of trans-10, cis-12 CLA on adipocyte differentiation of ovine preadipocytes. Differentiation of these preadipocytes was facilitated by treatment with trans-10, cis-12 CLA. Trans-10, cis-12 CLA increased the number and size of oil red O-stainable lipid drops as well as the levels of GPDH activity. PPAR-$\gamma{2}$ and adipophilin mRNA, adipogenic marker genes, were increased by treatment with trans-10, cis-12 CLA. This result was different from that observed with 3T3-L1 preadipocytes, a clonal cell line derived from rodents. Furthermore, trans-10, cis-12 CLA alone induced the adipocyte differentiation of ovine preadipocytes in differentiation-induction medium without troglitazone. These results suggest that CLA is an inducer and regulator in adipocyte differentiation of ovine preadipocytes, with species differences between ovine and rodent preadipocytes.

• Korean journal of food and cookery science
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• v.6 no.2
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• pp.37-50
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• 1990

The cause and the degree of the cis to trans isomerization were investigated about soybean oil (SBO), corngerm oil (CGO), cottonseed oil (CSO), margarine (MG) and shortening (ST). All samples treated with various conditions were analyzed to determine physicochemical characteristics (AV, POV, IV, RI), fatty acid composition, total trans fatty acid content and change of trans fatty acid composition by GLC, IR and HPLC. The results were obtained as follows; 1. Physicochemical constants were changed with a gentle slope according to incubating period at 40${\pm}$2$^{\circ}C$ and physicochemical constants of margarine and shortening were changed, significiantly. 2. The saturation degree in the unsaturated fatty acid composition determined by GLC gradually were increased during incubation and heating periodically. For palmitic-and stearic acid content at the samples stored in the incubator, the saturation degrees were gradually increased. But for the case of heat treatment, they were increased more rapidly than other fatty acids. 3. Total trans fatty acid contents in each samples were determined by GLC, IR and HPLC, the amount of trans fatty acids were measured with discrepancy. It was caused by deviation of analytical instruments, methods and the kinds of samples. Trans fatty acids were measured more definitly in IR more than GLC and HPLC. On the other hand, total trans fatty acid contents in average levels for SBO, CGO, CSO, MG and ST stored for 35 days and heated for 24 hours were 1.3%, 1.1%, 0.9%, 22.6% and 13.8%, and 3.6%, 3.0%, 2.8%, 41.2% and 20.8%, respectively.