• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.67-72
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• 2013

The LNG liquefaction plant which have a higher value-added business in the LNG value chain takes about 35% of total cost. Liquefaction process is core technology of liquefaction plant. Almost all of cost which was consumed from the liquefaction plant, using for operation energy of liquefaction process. The cost can be reduced by increasing efficiency of liquefaction cycle. C3MR(propane pre-cooled, mixed refrigerant cycle) which liquefies NG using propane and MR cycle has the high efficiency, so C3MR is mostly used liquefaction process in LNG industry. In this study, process simulation and analysis were performed for C3MR process. C3MR process variables were found through this simulation and analysis, and then the process optimization was performed. It is considered that the results of process analysis, process variables and process optimization study can be utilized to develope new liquefaction process.

• Bulletin of the Korean Mathematical Society
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• v.37 no.4
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• pp.803-810
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• 2000

Let N($d_1,...,{\;}d_n;c_1,...,{\;}c_n$) be the number of solutions $(x_1,...,{\;}x_n){\in}F^{n}_p$ of the diagonal equation $c_lx_1^{d_1}+c_2x_2^{d_2}+{\cdots}+c_nx_n^{d_n}{\;}={\;}0{\;}n{\geq},{\;}c_j{\;}{\in}{\;}F^{*}_q,{\;}j=1,2,...,{\;}n$ where $d_j{\;}>{\;}1{\;}and{\;}d_j{\;}$\mid${\;}q{\;}-{\;}1$ for all j = 1,2,..., n. In this paper, we find all n-tuples ($d_1,...,{\;}d_n$) such that the reduced form of ($d_1,...,{\;}d_n$) and N($d_1,...,{\;}d_n;c_1,...,{\;}c_n$) are the same as in the theorem obtained by Sun Qi [3]. Improving this, we also get an explicit formula for the number of solutions of the diagonal equation, unver a certain natural restriction on the exponents.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.68-73
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• 1995

Pseudomonas sp. P20 was shown to be capable of degrading biphenyl and 4-chlorobiphenyl (4CB) to produce the corresponding benzoic acids wnich were not further degraded. But the potential of the strain for biodegradation of 4CB was shown to be excellent. The pcbA, B, C and D genes responsible for the aromatic ring-cleavage of biphenyl and 4CB degradation were cloned from the chromosomal DNA of the strain. In this study, the pebC and D genes specifying degradation of 2, 3-dihydroxybiphenyl (2, 3-DHBP) produced from biphenyl by the pebAB-encoded enzymes were cloned by using pBluescript SK(＋) as a vector. From the pCK102 (9.3 kb) containing pebC and D genes, pCK1022 inserted with a EcoRI-HindIII DNA fragment (4.1 kb) carrying pebC and D and a pCK1092 inserted with EcoRI-XbaI fragment (1.95 kb) carrying pebC were constructed. The expression of pcbC and D' in E. coli CK102 and pebC in E. coli CK1092 was examined by gas chromatography and UV-vis spectrophotometry. 2.3-dihydroxybiphenyl was readily degraded to produce meta-cleavage product (MCP) by E. coli CK102 after incubation for 10 min, and then only benzoic acid(BA) was detected in the 24-h old culture. The MCP was detected in E. coli CK1022 containing pebC and 0 genes (by the resting cells assay) for up to 3 h after incubation and then diminished completely in 8 h, whereas the MCP accumulated in the E. coli CK1092 culture even after 6 h of incubation. The 2, 3-DHBP dioxygenases (product of pebC gene) produced by E. coli CK1, CK102, CK1023, and CK1092 strains were measured by native PAGE analysis to be about 250 kDa in molecular weight, which were about same as those of Pseudomonas sp. DJ-12, P. pseudoa1caligenes KF707, and P. putida OU83.

• Journal of applied mathematics & informatics
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• v.42 no.3
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• pp.511-520
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• 2024

In this paper, we introduce the concept of split and non-split tree (D, C)- set of a connected graph G and its associated color variable, namely split tree (D, C) number and non-split tree (D, C) number of G. A subset S ⊆ V of vertices in G is said to be a split tree (D, C) set of G if S is a tree (D, C) set and ⟨V - S⟩ is disconnected. The minimum size of the split tree (D, C) set of G is the split tree (D, C) number of G, γ_χST (G) = min{|S| : S is a split tree (D, C) set}. A subset S ⊆ V of vertices of G is said to be a non-split tree (D, C) set of G if S is a tree (D, C) set and ⟨V - S⟩ is connected and non-split tree (D, C) number of G is γ_χST (G) = min{|S| : S is a non-split tree (D, C) set of G}. The split and non-split tree (D, C) number of some standard graphs and its compliments are identified.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.874-880
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• 2010

A series of 13- and 14-membered cyclic enkephalin analogs based on the moderately $\mu$ selective prototype compound Tyr-C[D-$A_2bu$-Gly-Phe-Leu] 8a were synthesized to investigate the structure-activity relationship. The modifications of sequence were mainly focused on two positions 3 and 5, critical for the selective recognition for $\mu$ and $\delta$ opioid receptors. The substitution of hydrophobic $Leu^5$ with hydrophilic $Asp^5$ derivatives led to Tyr-C[D-$A_2bu$-Gly-Phe-Asp(N-Me)] 7 and Tyr-C[D-Glu-Phe-gPhe-rAsp(O-Me)] 5, the peptides with a large affinity losses at both $\mu$ and $\delta$ receptors. The substitution of $Phe^3$ with $Gly^3$ led to Tyr-C[D-Glu-Gly-gPhe-rLeu] 3 and Tyr-C[D-Glu-Gly-gPhe-D-rLeu] 4, the peptides with large affinity losses at $\mu$ receptors, indicating the critical role of phenyl ring of $Phe^3$ for $\mu$ receptor affinities. One atom reduction of the ring size from 14-membered analogs Tyr-C[D-Glu-Phe-gPhe-(L and D)-rLeu] 6a, 6b to 13-membered analogs Tyr-C[D-Asp-Phe-gPhe-(L and D)-rLeu] 1, 2 reduced the affinity at both $\mu$ and $\delta$ receptors, but increased the potency in the nociceptive assay, indicating the ring constrain is attributed to high nociceptive potency of the analogs. For the influence of D- or L-chirality of $Leu^5$ on the receptor selectivity, regardless of chirality and ring size, all cyclic diastereomers displayed marked $\mu$ selectivity with low potencies at the $\delta$ receptor. The retro-inverso analogs display similar or more active at $\mu$ receptor, but less active at $\delta$ receptor than the parent analogs.

• Journal of the Korean Magnetic Resonance Society
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• v.3 no.1
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• pp.12-26
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• 1999

The 1H NMR signals of the heme methyl, propionate and related chemical groups of cytochrome C3 from Desulfovibrio vulgaris Miyazaki F (D.v. MF) were assigned by means of 1D NOE, 2D DQFCOSY and 2D TOCSY spectra. They were consistent with the assignments of the hemes with the highest and second-lowest redox potentials reported by Gayda et al. [Reference: 15]. The heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val-18, All the results contradicted the heme assignments for D.v. MF cytochrome C3 made on the basis of NMR [Reference: 11]. Based on these assignments, the interaction of cytochrome C3 with ferredoxin I was investigated by NMR. The major interaction site of cytochrome C3 was identified as the heme with the highest redox potential, which is surrounded by the highest density of positive charges. The stoichiometry and association constant were two cytochrome C3 molecules per monomer of ferredoxin I and 108 M-2 (at 53 mM ionic strength and $25^{\circ}C$), respectively.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1463-1468
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• 2007

Emission of methyl bromide(MeBr) of soil fumigant was implicated in stratospheric ozone depletion. To determine the environmental fate for 1,3-dichloropene(1,3-D) of alternatives fumigants for MeBr, this paper researched the transformation for 1,3-D in water and soil. Half lives of cis-1,3-D in water with first-order kinetics are 9.9day and 1.7day at $25^{\circ}C\;and\;40^{\circ}C$, half lives of trans-1,3-D are 8.6day and 1.5day at $25^{\circ}C\;and\;40^{\circ}C$, respectively. Transformation for 1,3-D in water at high temperature faster then at low temperature. Hydrolysis for 1,3-D in water are unaffected at $pH\;2.5{\sim}pH\;10.0$, but hydrolysis for 1,3-D at pH 11.5 higher then at $pH\;2.5{\sim}pH\;10.0$. Half lives of cis-1,3-D in soil are 11.5day and 7.7day at 3% and 10% of soil moisture, half lives of trans-1,3-D are 9.9day and 6.9day at 3% and 10% of soil moisture, respectively. Transformation for 1,3-D in water increased with increasing soil moisture. Transformation for trans-1,3-D isomer are more rapid then cis-1,3-D isomer in water and soil. This research has identified that transformation for 1,3-dichloropropene are affected by temperature, pH, soil moisture, and isomer of cis and trans in water and soil.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.1-4
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• 1990

Reaction of propane-1, 3-sultone with amines gave N-substituted aminosulphonnic acids 2a-i, Dehydration of 2a-c with $POCI_3$ gave the corresponding sultams 3a-c. Propane-1, 3-sultone 1 reacted with tertury amines to give the betaiene salts 4-11. 2-4-Dimethyl-1, 3-butadiene-1, 4-sultone 12 condensed with amines to give N-substituted-2, 4-dimethyl-1, 3-butadiene-1, 4-sultames 13a and 13b. The reaction of 3a, 13a with hydrazine hydrate gave acid hydrazides 3d or 13c. Compounds 3d, 13c reacted with isocyanates to yield urea derivatives 14a-c, 15a-c.

• KSBB Journal
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• v.24 no.1
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• pp.53-58
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• 2009

This study was focused on the investigation of the characteristics of TPH and BTEX removal in oil-contaminated sandy soil and fine soil with injection of microorganisms, nutrients, and surfactants. As the result of the experiments maintained moisture contents by 10${\sim}$20%, the TPH removal efficiency in oil-contaminated sandy soil was the highest in C-1 (microorganisms+nutrients), and the efficiency in C-2 (microorganisms+nutrients+surfactants) was higher than the efficiency in C-0(microorganisms). In 81 days, TPH removal efficiency in case of C-0, C-1 and C-2 showed 51%, 83%, 63% respectively. The results of D group with fine soil showed similar trends as C group, but the TPH removal efficiency of D group was lower than that of C group. Those of both C and D group were the highest in 1 group (microganisms+nutrients). The pH of fine soil was some lower than that of sandy soil or was similar to sandy soil. In 14 days, BTEX removal efficiency in case of C-0, C-1, C-2, D-0, D-1 and D-2 showed 99.8%, 99.4%, 96.0%, 99.5%, 99.2%, 96.3% respectively. Those of both C and D group were the highest in 0 group (microganisms).

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.359-364
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• 1996

$SrTiO_3$ thin films were deposited on Pt/Ti/$SiO_2$/Si substrates at low temperatures below $300^{\circ}C$ by r.f. magnetron sputtering. The materials and the electrical properties of the deposited films were investigated with controlling deposition parameters such as substrate temperature(T_s) and positive substrate d.c. bias voltage. Stoichiometric $SrTiO_3$ films were obtained at Ts of $300^{\circ}C$, but Sr content in the film was less than that of a target when Ts was lower than $300^{\circ}C$, resulting in poor electrical properties. By introducing a positive substrate d.c. bias during deposition, the crystallinity and the dielectric properties of the films were markedly improved. 400 nm thick $SrTiO_3$, films deposited at $300^{\circ}C$ with a positive substrate d.c. bias of 20V showed a columnar structure with <211> crystallographic direction and a dielectric constant of 98.