• Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.175-186
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• 2022

Sea mustard (Undaria pinnatifida), an important edible seaweed belonging to the brown algal family of Alariaceae, contains copious physiologically active substances. It has long been popular in Korea as a food and is frequently consumed in the form of soup. It is also commercially available as a home meal replacement. In this study, we developed a seasoning key base with a high degree of sensory preference from sea mustard using the extrusion cooking process. Extrusion cooking conditions were optimized through response surface methodology. Barrel temperature (X₁, 140℃-160℃) and screw speed (X₂, 158-315 rpm) were set as independent variables, and overall preference was determined as the dependent variable (Y, points). An optimal condition was obtained at X₁ = 148.5℃ and X₂ = 315 rpm, and the dependent variable (Y, overall acceptance) was 7.95 points, similar to the experimental value of 7.81. Umami taste had a relationship with the overall acceptance of sea mustard seasoning. In the electronic nose and tongue, increased sourness and umami intensities were associated with the highest sensory score. The samples were separated well by each characteristic via principal component analysis. Collectively, our study provides imperative preliminary data for the development of various seasonings using sea mustard.

• Journal of electromagnetic engineering and science
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• v.6 no.2
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• pp.83-91
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• 2006

In this paper, we develop space-time(ST) Rake receivers for Time Division Synchronous Code Division Multiple Access(TD-SCDMA) base stations(BS). The beamforming of BS transforms the uplink MIMO channel space into many sub-sectors' channels to be nearly orthogonal, thus, well established 1-D Rake technology can be used to TD-SCDMA base station to construct ST Rake, which simplified the system's implementation as well as enlarged users' capacity by the beamforming. The construction and capacity of MIMO sub-sectors by multi-beamforming have been presented. The proposed ST Rake algorithm include the multi-beamforming algorithm for MIMO sub-sectors and classical 1-D Rake algorithm. The calculating formulas for interference plus noise ratio(SINR) and bit error rate(BER) have been derived. Simulations verify that the proposed ST Rake receiver for BS is effective, and the BS systems can get higher system capacity and can be of better performance than presented TD-SCDMA systems.

• Analytical Science and Technology
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• v.36 no.2
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• pp.70-79
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• 2023

The synthesis of the Mannich base as a ligand (L) N-(morpholino (phenyl) methyl) acetamide is the subject of this study. Elemental analyses, FT-IR spectra, UV-vis, ¹H-NMR, and magnetic measurements were used to confirm the synthesis of the [Ni(L)₂]Cl₂ complex, thermal analysis (TG/DTG), atomic absorption, and scanning, and structurally explained as electron microscopy (SEM), and X-ray powder diffraction (XRD) methods. The melting point of the complex and its molar conductivity were also measured. The suggested geometries of the complexes formed have a tetrahedral structure, according to the data acquired using various techniques. Theoretical approaches to the complex formation have been investigated. For molecular mechanics and semi-empirical calculations, the HYPERCHEM6 program had been used. The effect of the novel Ni(II) complex on the cancer cell Hepa-2 (human hepatocellular ademocarcinoma), that is the human laryngeal cancer, was studied. It has been found that these ligand and complex have potent effects on the cancer cell. The antibacterial activity of the free ligand and its complex was evaluated against two kinds of human pathogenic bacteria. The first category is Gram-positive (Staphylococcus aureas, epiderimids), whereas the second group is Gram-negative (Psedamonas aeruginosa, Escherichia coli) (from the diffusion method). Finally, it was discovered that various chemicals had varied growth-inhibiting effects on bacteria.

• Wind and Structures
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• v.11 no.5
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• pp.377-389
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• 2008

An experimental investigation has been conducted to determine the effectiveness of base shield plates in reducing the drag of a rough circular cylinder in a cross flow at Reynolds numbers in the range $3{\times}10^4{\leq}Re{\leq}10.5{\times}10^4$. Three model configurations were investigated and compared: a plane cylinder (PC), a cylinder with a splitter plate (MC1) and a cylinder fitted with base shield plates (MC2). Each configuration was studied in the sub and supercritical flow regimes. The chord of the plates, L, ranged from 0.22 to 1.50D and the cavity width, G, between the plates was in the range from 0 to 0.93D. It is recognized that base shield plates can be employed more effectively than splitter plates to reduce the aerodynamic drag of circular cylinders in both the sub- and supercritical flow regimes. For subcritical flow regime, one can get 53% and 24% drag reductions for the MC2 and MC1 models with L/D=1.0, respectively, compared with the PC model. For supercritical flow regime however, the corresponding drag reductions are 38% and 7%.

• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1365-1366
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• 2002

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1046-1049
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• 2002

In this paper, a sub-harmonic dual-gate FET mixer for IMT-2000 base-station was designed by using single-gate FET cascode structure and driven by the second order harmonic component of LO signal. The dual-gate FET mixer has the characteristic of high conversion gain and good isolation between ports. Sub-harmonic mixing is frequently used to extend RF bandwidth for fixed LO frequency or to make LO frequency lower. Furthermore, the LO-to-RF isolation characteristic of a sub-harmonic mixer is better than that of a fundamental mixer because the frequency separation between the RE and LO frequency is large. As RF power is -30dBm and LO power is 0dBm, the designed mixer shows the -47.17dBm LO-to-RF leakage power level, 10dB conversion gain, -0.5dBm OIP3, -10.5dBm IIP3 and -1dBm 1dB gain compression point.

• BMB Reports
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• v.31 no.1
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• pp.89-94
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• 1998

The structures of the self-complementary decamer duplexes, $d(ACGTATACGT)_2$ (TATA-duplex) and $d(ACGTTAACGT)_2$, (TTAA-duplex) has been obtained in solution by proton NMR spectroscopy and restrained molecular dynamics. The duplexes are essentially B-type, with distortions apparent at the TATA and TTAA steps. Theses distortions and their effects on dynamics have been investigated by the measurement of imino proton exchange time of the base-pairs. The unusual opening kinetics of central A T base-pairs could be correlated to the abnormal structural properties of the corresponding sequences.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.63-72
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• 2013

Some vanadyl complexes were synthesized by treating a methanolic solution of the appropriate Schiff base ligand and one equivalent of $VO(SO_4)_2$ to yield [($VOL_2^{1-14}$)](L=Salicylaldehyde's derivatives, Schemes 1, 2). These oxovanadium (IV) complexes were characterized based on their FT-IR, UV-Vis spectroscopy and elemental analysis. The IR spectra suggest that coordination takes place through azomethine nitrogen and phenolate oxygen. In addition, the formation constants of the oxovanadium (IV) binary complexes were determined in methanolic medium. The ab initio calculations were also carried out to determine the structural and the geometrical properties of one of the complexes and its calculated vibrational frequencies were investigated.

• Journal of the Korean GEO-environmental Society
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• v.14 no.7
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• pp.51-56
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• 2013

Recently, a top record of hourly-based rainfall has been changed annually and flood damages of road have increased. To solve this problem, pavements for drainage were developed and practically constructed but there was no considerations on sub-base. In this research, we proposed standard for distribution of particle size of sub-base to consider strength characteristic and drainage property. We focused to compare coefficients strength and permeability by laboratory tests. Prior to tests, 4 samples were selected under the consideration on the international or domestic design guideline. In the tests, strength characteristics were compared with resilient modulus. Also, permeability characteristics were compared with coefficient of upward and downward permeability. Resilient modulus was determined with MR test using cyclic triaxial testing system. Two permeability tests were carried out. One is variable head permeability test for downward drainage and the other is Rowe Cell test for upward drainage. In the case of Rowe Cell test, middle-sized sampler with 150mm diameter was used for this study. Consequentially, we tried to find the optimum distribution of particle size to satisfy both of strength and permeability characteristics for sub-base.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2454-2458
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• 2007

Exploring the basic concepts for the design of CO2-philic molecules is important due to the possibility for “green” chemistry in supercritical CO2 as substitute solvent systems. The Lewis acid-base interactions and C?H…O weak hydrogen bonding were suggested as two key factors for the solubility of CO2-philic molecules. We have performed high level quantum mechanical calculations for the van der Waals complexes of CO2 with trimethylphosphate and trimethylphosphine oxide, which have long been used for metal extractants in supercritical CO2 fluid. Structures and energies were calculated using the MP2/6-31+G(d) and recently developed multilevel methods. These studies indicate that the Lewis acid-base interactions have larger impact on the stability of structure than the C?H…O weak hydrogen bonding. The weak hydrogen bonds in trimethylphosphine oxide have an important role to the large supercritical CO2 solubility when a metal is bound to the oxygen atom of the P=O group. Trimethylphosphate has many Lewis acid-base interaction sites so that it can be dissolved into supercritical CO2 easily even when it has metal ion on the oxygen atom of the P=O group, which is indispensable for a good extractant.