• KSBB Journal
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• v.15 no.3
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• pp.299-306
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• 2000

Concern for the effects of toxic chemicals on the environment leads the search for better bioassay test organisms and test procedures. Photobacterium phosphoreum was used successfully as a test organism and the luminometer detection technique was an effective and simple method for determining the concentration of toxic chemicals. With EC50 a total of 14 chlorine substituted phenols benzenes and ethanes were used for the experiments. The test results showed that the toxicity to P. phosphoreum increased in the order of phenol > benzene > ethane and the toxicity also increased with the number of chlorine substitution. Quantitative structure activity relationship (QSARO) model can be used to predict EC50 to save time and endeavor. Correlation was well established with the QSAR parameters such as log P, log S and solvatochromic parameter(Vi/100 $\pi$, ${\beta}$m and am). The QSAR modeling was used with multi-regression analysis and mono-regression analysis. These analyses resulted in the following QSAR : $log EC_{50} =2.48 + 0.914 log S(n=9 R2=85.5% RE=0.378) log EC_{50}=0.35 - 4.48 Vi/100 + 2.84 \pi^* +9.46{\beta}m-4.48am (n =14 R2=98.2% RE=0.012) log EC_{50} =2.64 -1.66 log P(n=5, R2=98.8% RE=0.16) log EC_{50}=3.44 -1.09 log P(n=9 R2= 80.8% Re=0.207)$

• Journal of the korean Society of Automotive Engineers
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• v.2 no.1
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• pp.21-31
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• 1980

Two phase boundary layer equations of laminar filmwise condensation are solved by an approximate integral method under the following condition; saturated vapour flows vertically downward over a cooled surface of uniform temperature, the condensate film is so thin that the inertia and convection terms are neglected. The following conclusions are drawn under the above assumptions. 1. free convection In case of the linear temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$=4/3,(G $r_{l}$ /4.H)$^{1}$4/ and in case of the quadratic profile, numerical results may be expressed as N $u_{m}$=2/1.682,(G $r_{l}$ /H)$^{1}$4/. 2. Forced convection When the temperature profile is assumed to be linear in a liquid film, numerical results fir the average heat transfer coefficients may be expressed as N $u_{m}$=(A, R $e_{l}$ /H)$^{1}$2/. This expression is compared with the experimental results hitherto reported; For theoretical Nusselt number (N $u_{m}$)$_{th}$<2*10$^{4}$, the experimental Nusselt number (N $u_{m}$)$_{exp}$ is on the average larger than theoretical Nusselt number (N $u_{m}$)$_{th}$ by 30%. For (N $u_{m}$)$_{th}$>2*10$^{4}$, experimental Nusselt number (N $u_{m}$)$_{exp}$ is about 1.6 times as large as theoretical Nusselt number (N $u_{m}$)$_{th}$. These large deviation may be caused by the presence of turbulence in the liquid film. In case of the quadratic temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$'=(2,A,Re/H)$^{1}$2/. This formular shows that theoretical Nusselt number (N $u_{m}$)$_{th}$ is larger than experimental Nusselt number (N $u_{m}$)$_{exp}$ by 60%. It is speculated that when the temperature difference between cooled surface and saturated vapour is small, temperature profile in a liquid film is quadratic.quadratic.. quadratic.quadratic..atic..

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1257-1263
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• 2010

The naval structure exposes to environmental vibration of shafted propeller propulsion and engine vibration. The shipboard equipments are developed compliance to MIL-STD-167-1A. For this purpose, vibration fatigue life of shipboard equipment for long lives should be estimate via an analytical approach and vibration test. In this paper, High cycle fatigue strength of cast aluminum alloy A356 using shipboard equipment was evaluated by 14 S-N method. The stress applied on the structure is evaluated by an analytical method(frequency response analysis with sinusoidal input and a fatigue evaluation) to simulate a MIL-STD-167-1A test. The frequency with the maximum equivalent stress is shown by Max. test frequency and the vibration fatigue life of shipboard equipment was estimated by Miner's rule.

• Honam Mathematical Journal
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• v.31 no.1
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• pp.45-61
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• 2009

We consider finite time blowup solutions of the $L^2$-critical focusing Hartree equation on $\mathbb{R}^n$, $n{\geq}3$ below $H^1$.

• ETRI Journal
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• v.31 no.1
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• pp.68-70
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• 2009

In this letter, a parametric analysis of the Fresnel-field antenna measurement method is performed for a square aperture. As a result, the optimum number of Fresnel fields for one far-field point is guided as $M_{opt}=N_{opt}=D^2/{\lambda}R+5$, where D is the antenna diameter, ${\lambda}$ is the wavelength, and R is the distance between the source antenna and the antenna under test. For the aperture size 5 ${\leq}$ $L_x/{\lambda}$ ${\leq}$ 20, the tolerable distances for gain errors of 0.5 dB and 0.2 dB can be guided as $R_{0.5\;dB}$ ${\approx}$ $1.2Lx/{\lambda}$ and $R_{0.2\;dB}$ ${\approx}$ $2.0L_x/{\lambda}$, where $L_x$ is the lateral length of the square aperture. The tolerable distances for 20 ${\leq}$ $L_x/{\lambda}$ ${\leq}$ 200 are also proposed. This measurement guideline can be fully utilized when performing the Fresnel-field antenna measurement method.

• Environmental Engineering Research
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• v.19 no.4
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• pp.317-329
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• 2014

The diversity of cyanobacteria in Sri Lanka was studied in different water reservoirs, paddy fields, brackish water and tsunami affected areas using light microcopy, 16S rRNA sequences, followed by phylogenetic analysis. Based on light microscopy, 24 genera were identified from environmental samples belonging to the orders Chroococcales, Oscillatoriales, Pleurocapsales and Nostocales. In cultures, 33 genera were identified from all five cyanobacterial orders, including Stigonematales. Based on 16S rRNA gene sequences and their morphology, two isolates were identified up to species level, 72 to genus level, one isolate up to family and 11 up to order level. Twelve isolates couldn't be assigned to any taxonomic level. The results of 16S rRNA gene sequences along with the phylogenetic analysis indicated that some cyanobacterial isolates could be accommodated to genus or order level. The 16S rRNA sequence analysis data in this study confirmed that order Nostocales and order Pleurocapsales cyanobacteria are monophyletic while orders Chroococcales, Oscillatoriales and Stigonematales cyanobacteria are polyphyletic. Polyphasic approach including the combination of light microscopy, cultures and the analysis of 16S rRNA gene sequences provide a promising approach to ascertain the diversity of cyanobacteria in different habitats.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.163-170
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• 2021

Enzyme replacement therapy for lysosomal storage diseases usually requires recombinant enzymes containing mannose-6-phosphate (M6P) glycans for cellular uptake and lysosomal targeting. For the first time, a strategy is established here for the in vitro mannosyl-phosphorylation of high-mannose type N-glycans that utilizes a recombinant Mnn14 protein derived from Saccharomyces cerevisiae. Among a series of N-terminal- or C-terminal-deleted recombinant Mnn14 proteins expressed in Pichia pastoris, rMnn1477-935 with deletion of N-terminal 76 amino acids spanning the transmembrane domain (46 amino acids) and part of the stem region (30 amino acids), showed the highest level of mannosyl-phosphorylation activity. The optimum reaction conditions for rMnn1477-935 were determined through enzyme assays with a high-mannose type N-glycan (Man8GlcNAc2) as a substrate. In addition, rMnn1477-935 was shown to mannosyl-phosphorylate high-mannose type N-glycans (Man7-9GlcNAc2) on recombinant human lysosomal alpha-glucosidase (rhGAA) with remarkably high efficiency. Moreover, the majority of the resulting mannosyl-phosphorylated glycans were bis-form which can be converted to bis-phosphorylated M6P glycans having a superior lysosomal targeting capability. An in vitro N-glycan mannosyl-phosphorylation reaction using rMnn1477-935 will provide a flexible and straightforward method to increase the M6P glycan content for the generation of "Biobetter" therapeutic enzymes.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.686-689
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• 2003

A Gene content phylogenetic tree and a 16S rRNA based phylogenetic tree were compared for 9 Archaea and 15 Proteobacteria, whole-genome sequenced, by neighbor joining and bootstrap methods (n=1000). Ratio of conserved COG (clusters of orthologous groups of proteins) to ortholog revealed that they were within the range of 4.60% (Mezorhizobium loti) or 56.57% (Mycoplasma genitalium), The diversity of ratio meant the Possibility of searching for useful genes, as they possess peculiar genes. The gene content tree and the 16S rDNA tree showed coincidence and discordance in Archaea and Proteobacteria.

• Nuclear Engineering and Technology
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• v.6 no.2
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• pp.89-96
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• 1974

The cross-section ratios of the nuclear isomeric pairs $^{80}$ B $r^{m, g}$, sup 81/S $e^{m, g}$, $^{104}$ R $h^{m, g}$, $^{116}$ I $n^{m, g}$ and $^{134}$ C $s^{m, g}$ through the radiative thermal neutron capture process have been studied. The experimental values of these ratios obtained by the activation method have been compared with the calculated ones deduced from the modified Huizenga-Vandenbosch method. Agreement between these values within 30% could be attained by controlling the spin cut-off parameter and gamma-ray multiplicity.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.20-24
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• 2012

Denitrification rate was determined for various freshwater wetland types in the Mississippi River Coastal delta plain. Site 1 and 4 were collected from forested-tupelo dominated wetland, and site 2 and 3 were from floating emergent marsh. The maximum $N_2O$ emission was $7.47mg\;N\;m^{-2}$ for site 1 at day 6 after the addition of nitrate, $6.96mg\;N\;m^{-2}$ for site 2 at day 4, $6.63mg\;N\;m^{-2}$ for site 3 at day 3, and $9.64mg\;N\;m^{-2}$ for site 4 at day 4. The denitrification rate was determined using the acetylene inhibition method $1.24mg\;N\;m^{-2}d^{-1}$ for site 1, $1.93mg\;N\;m^{-2}d^{-1}$ for site 2, $2.24mg\;N\;m^{-2}d^{-1}$ for site 3, and $2.78mg\;N\;m^{-2}d^{-1}$ for site 4. The maximum denitrification rate was in the order of site 4 > site 3 > site 2 > site 1.