• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.705-714
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• 2008

Three Mesh Screenning Reactors (MSRs) were operated in three different modes to investigate the effect of the mesh opening size and the filtrate flux on the removal of particulate matters and the production of soluble organic matters. The mesh opening size was $82{\mu}m$ (Mode 1), $61{\mu}m$ (Mode 2) and $38{\mu}m$ (Mode 3), respectively, and each mode has three different filtrate flux; $0.47m^3/m^2/d$, $0.95m^3/m^2/d$ and $1.42m^3/m^2/d$, respectively. TSS removal efficiency of mode 1, 2, and 3 fed with 191 mgTSS/L was 27%, 36%, and 60%, respectively. The SCOD concentration of 91mg/L in influent for the mode 1, 2, and 3 increased to 117 mg/L, 127 mg/L, and 155 mg/L, respectively. For the all MSRs, there was no significant effect of filtrate flux on the removal of particulate matters and the production of soluble organic matters. However, the mesh opening size greatly affected the removal of particulate matters and the production of soluble organic matters in wastewater. Three parallel A2O processes consisting of anaerobic, anoxic and aerobic reactors maintaining mixed liquor suspended solids (MLSS) of 3,000 mg/L were operated to investigate the effectiveness of MSR on the removal efficiencies of the organic matters, nitrogen, and phosphorus; MSR influent was introduced to System 1 (183 mgTSS/L, 324 mgTCOD/L, 87 mgSCOD/L, 45.2 mgTKN/L, and 6.6 mgTP/L) and MSR efluent was introduced to System 2 and 3(72 mgTSS/L, 289 mgTCOD/L, 141 mgSCOD/L, 40.2 mgTKN/L, and 4.2 mgTP/L). HRTs of the anaerobic reactors in systems 1, 2 and 3 were 1 h, 1 h and 0.6 h, respectively and anoxic reactors were 2 h in all systems. HRTs of the aerobic reactors in systems 1, 2 and 3 were 5 h, 3 h and 3 h, respectively. TSS concentration in effluent of both system 2 and 3 is about 8 mg/L and lower than that of system 1 effluent. Despite higher TCOD loading and SCOD loading, both Systems 2 and 3 had a greater TCOD and SCOD removal efficiency at 91% and 92% than System 1 was at 88% and 82%, respectively. The nitrification efficiency for system 2 was greater than observed for System 1 (99% verses 97%). The denitrification efficiency for systems 1, 2 and 3 was 78%, 88% and 87%, respectively. System 2 and 3 showed about 12% higher TN removal efficiency than system 1 (85% verses 73%). The effluent TP concentration for system 2 was less than observed for system 1 and 3.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.101-107
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• 2016

This paper investigates the feasibility of applying the jet loop reactor for the neutralization of alkaline wastewater using carbon dioxide ($CO_2$). In this study, pH changes and $CO_2$ removal characteristics were examined by changing influent flow rate of alkaline wastewater (initial pH=10.1) and influent $CO_2$ flow rates. Influent flow rates of alkaline wastewater ($Q_{L,in}$) ranged between 0.9 and 6.6 L/min, and inlet gas flow rate ($Q_{G,in}$) of 1 and 6 L/min in a lab-scale continuous flow jet loop reactor. The outlet pH of wastewater was maintained at 7.2 when the ratio ($Q_{L,in}/Q_{G,in}$) of $Q_{L,in}$ and $Q_{G,in}$ was 1.1. However, the $CO_2$ removal efficiency and the outlet pH of wastewater were increased when $Q_{L,in}/Q_{G,in}$ ratio was higher than 1.1. Throughout the experiments, the maximum $CO_2$ removal efficiency and the outlet pH of wastewater were 98.06% and 8.43 at the condition when $Q_{G,in}$ and $Q_{L,in}$ were 2 L/min and 4 L/min, respectively.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.63-67
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• 2002

Bifidobacterium strain was isolated from the feces of brast fed infants. The isolated strain was identified as Bifidobacterium longum by 16S rRNA sequence analysis and named as Bifidobacterium SH2. The MRS medium was modified to obtain high density cells of Bifidobacterium SH2. The optimal medium was determined to be 50 g/L lactose, 10 g/L beef extract, 10 g/L peptone, 5 g/L yeast extract, 7 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L disodium phosphate,1 g/L tween 80, 0.2 g/L MnSO$_4$ and 0.5 g/L L-cysteine. The pH and temperature were optimized as 5.0 and $37^{\circ}C$, respectively. Through out the optimization of medium composition and culture conditions, the dry cell weight and viable cell count were 2.5 times and 1.8 times higer than those in MRS medium, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.10
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• pp.990-998
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• 2011

In this paper, we have designed a multi-band single layer microstrip patch antenna with slots for GPS L2/L1, GLONASS receivers. The antenna has dual feed structure and consists of single layer microstrip patch with slots and impedance matching circuit. The antenna specifications are a VSWR(Voltage Standing Wave Ratio) of less than 2.0, RHCP(Right-Hand Circular Polarization) characteristics over the operating frequency bands of GPS L2(1,227.6 MHz)/L1(1,575.42 MHz) and GLONASS(1,602 MHz), the maximum active antenna gain of more than 30 dB and the axial ratio of less than 3 dB. The antenna has been successfully evaluated by various tests.

• Journal of Microbiology and Biotechnology
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• v.2 no.2
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• pp.73-77
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• 1992

The effect of a nisin-producing Lactococcus lactis spp. lactis (L. lactis) on the growth and attachment of Listeria monocytogenes Scott A and Brie 1 on stainless steel and their growth in Brain Heart Infusion broth was determined. Viable cells of Listeria decreased rapidly after 9~12 hr of incubation at $21^{\circ}C$ and after 6~9 hr of incubation at $32^{\circ}C$ in the presence of L. lactis. The number of L. monocytogenes Scott A attached to stainless steel in pure culture was $2.5{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.3{\times}10^3/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ after 48 hr of incubation, but was only $10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}1.1{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ in the presence of L. lactis. Results from L. monocytogenes strain Brie 1 were similar to those from strain Scott A. The population of L. monocytogenes Scott A which attached to stainless steel with previously adherent L. lactis was $1.8{\times}10^2/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}8.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, whereas the population attached to sterile stainless steel was $1.2{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.1{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. For L. monocytogenes Brie 1, the attached population of the control was $1.6{\times}10^4/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}3.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, and on stainless steel with adherent L. lactis, it was $1.1{\times}10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}6.9{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. Surface adherent L. lactis was less inhibitory to attachment of L. monocytogenes on stainless steel than a liquid culture inoculum. Listeria attached to stainless steel survived dry storage for 20 days both in the presence and absence of adherent lactococci.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.724-730
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• 2013

We investigated the effects of orally administered probiotic bacteria (Lactobacillus species) as allergic immune modulators in ovalbumin (OVA)-sensitized mice. BALB/c mice were intraperitoneally injected with OVA twice at a 2-week interval for allergy sensitization. The mice were then orally administered Lactobacillus casei YIT9029 (L1), L. casei HY7201 (L2), L. brevis HY7401 (L3), or L. plantarum HY20301 (L4) every 2 days for 3 weeks. Total IgE levels significantly decreased in sera of L3-administered mice but increased in the other groups. OVA-specific IgE levels decreased slightly in sera of mice administered L1, L3, and L4 but increased significantly in L2-administered mice. In passive cutaneous anaphylaxis (PCA) using sera from administered mice, only the L3-administered group showed reaction inhibition. High expression of TLR-2 with interferon (IFN)-${\gamma}$ stimulation on peripheral blood mononuclear cells occurred in L3- or L4-administered mice. Th1 cytokines, including IFN-${\gamma}$ and interleukin (IL)-12, increased in splenocytes of L3-administered mice; however, IL-4 decreased in L1- and L4-administered groups; IL-5 decreased in all experimental groups. IL-6 decreased in the L3-administered group; and IL-10 decreased in L1-, L2-, and L3-administered groups. L3 induced antiallergic effects by increasing Th1 cytokines, decreasing Th2 cytokines, and inhibiting the PCA reaction, whereas L2 administration increased allergic effects.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.598-601
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• 2006

The radio signal in GNSS was intentionally designed with two frequencies in order to combat the dispersion error caused by trans-ionospheric propagation. By measuring the path delay independently at the two, widely spaced GPS frequencies, L1 & L2, the TEC along the path from satellite to receiver can be measured directly. The issue with dual frequency measurement of the ionosphere is the calibration of L1/L2 interfrequency biases. L1/L2 interfrequency biases are generated because physical electric signal paths of L1 and L2 circuits are different from each other for both satellites and receiver. Conventionally L1/L2 interfrequency bias is estimated and broadcasted by 2D ionospheric model. In this paper, we estimated IFB (interfrequency bias) by 2D & 3D ionospheric models including real time filter methods and compared the result of those and concluded the merit of 3D tomography model to recover the problem of 2D thin shell model. We confirmed our conclusion by experimental data.

• Bulletin of the Korean Mathematical Society
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• v.52 no.3
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• pp.1007-1025
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• 2015

Let $\mathbb{N}_0$ be the set of non-negative integers, and let P(n, l) denote the set of all weak compositions of n with l parts, i.e., $P(n,l)=\{(x_1,x_2,{\cdots},x_l){\in}\mathbb{N}^l_0\;:\;x_1+x_2+{\cdots}+x_l=n\}$. For any element $u=(u_1,u_2,{\cdots},u_l){\in}P(n,l)$, denote its ith-coordinate by u(i), i.e., $u(i)=u_i$. A family $A{\subseteq}P(n,l)$ is said to be t-intersecting if ${\mid}\{i:u(i)=v(i)\}{\mid}{\geq}t$ for all $u,v{\epsilon}A$. A family $A{\subseteq}P(n,l)$ is said to be trivially t-intersecting if there is a t-set T of $[l]=\{1,2,{\cdots},l\}$ and elements $y_s{\in}\mathbb{N}_0(s{\in}T)$ such that $A=\{u{\in}P(n,l):u(j)=yj\;for\;all\;j{\in}T\}$. We prove that given any positive integers l, t with $l{\geq}2t+3$, there exists a constant $n_0(l,t)$ depending only on l and t, such that for all $n{\geq}n_0(l,t)$, if $A{\subseteq}P(n,l)$ is non-trivially t-intersecting, then $${\mid}A{\mid}{\leq}(^{n+l-t-l}_{l-t-1})-(^{n-1}_{l-t-1})+t$$. Moreover, equality holds if and only if there is a t-set T of [l] such that $$A=\bigcup_{s{\in}[l]{\backslash}T}\;A_s{\cup}\{q_i:i{\in}T\}$$, where $$A_s=\{u{\in}P(n,l):u(j)=0\;for\;all\;j{\in}T\;and\;u(s)=0\}$$ and $$q_i{\in}P(n,l)\;with\;q_i(j)=0\;fo\;all\;j{\in}[l]{\backslash}\{i\}\;and\;q_i(i)=n$$.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.74-80
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• 2002

The effect of the foliar application of amino acid mixture on the growth of melon (Cucumis melo L.) seedlings was investigated. The amino acid treatments were initiated at the first (Ll) or second (L2) fully expanded leaf stage. The concentrations of amino acid mixture used were 0,10, 20, and 30 mg . L$^{-1}$ . At Ll stage, the fresh and dry weights of shoot were high in the amino acid treatments. Plant height was the highest in 30 mg . L$^{-1}$ at the third sampling of Ll. At L2 stage, shoot fresh weight was the greatest when the concentration of amino acid mixture was 30 mg.L$^{-1}$ at the third sampling. Plant height was the highest in 30 mg L$^{-1}$ at the second and third samplings. At the third sampling of Ll stage the amino acid mixture affected leaf length and leaf width of the first true leaf. At the third sampling of L2 stage leaf length was not significantly dirtferent between treatments, while leaf width was greater in amino acid treatments. At the second and third samplings of Ll stage the amino acid mixture had effect on leaf length and leaf width of the second true leafs which were not significantly different between treatments at L2 stage. Leaf length and leaf width of the third true leaf were affected by amino acid treatments. In conclusion, when the first true leaf expanded\ulcorner three foliar applications of 20-30 mg . L$^{-1}$ amino acid mixture can stimulate the growth of melon seedlings. If the amino acid mixture is sprayed at the second true leaf stage, two foliar applications of 30 mg . L$^{-1}$ amino acid mixture can improve the growth of melon seedlings.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.419-424
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• 2005

Effect of temperature($22-32^{\circ}C$), pH(5-7) and medium composition on the mycelial growth for the submerged culture of Inonotus obliquus. The concentrations of glucose, starch, peptone, yeast extract, $K_2HPO_4$, $MgSO_4{\cdot}7H_2O$ and $CaCl_2$ were examined in the ranges of 30-120 g/L, 0-10 g/L, 0-20 g/L, 0-15 g/L, 0-2 g/L, 0-1.5 g/L and 0-0.5g/L, respectively. The maximum mycelial growth of Inonotus obliquus was obtained for $26-27^{\circ}C$ and pH 6. The concentrations of glucose, yeast extract and $CaCl_2$, which gave the maximum mycelial growth of Inonotus obliquus, were 70 g/L, 5 g/L and 0.1 g/L, respectively. In the cases of starch, peptone and $K_2HPO_4$, the mycelial growth of Inonotus obliquus increased with increasing the concentrations. However, as the concentration of $MgSO_4{\cdot}7H_2O$ increased, the mycelial growth of Inonotus obliquus decreased. The medium for maximum mycelial growth of Inonotus obliquus consisted of (per 1 L): glucose, 70 g; peptone, 5-20 g; starch, 10 g; yeast extract, 5 g; $K_2HPO_4$, 2 g and $CaCl_2$, 0.1 g.