• 한국환경보건학회지
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• 제27권2호
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• pp.92-99
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• 2001

This present study was aimed to investigate the characteristics of dissoloved organic matter (DOC) in sewage. The results are summarized as follows ; The plateaux reached in 3~4 days by the biodegradability test on sewage samples based on DOC. 쏭 rations of BDOC to DOC were 48, 21, 13 and 11% for raw sewage, primary treatment effluent, secondary treatment effluent and final treatment effluent, respectively. As the SUVA values ranged less 3L/m.mg for the effluent of sewage treatment plant, the DOC is composed largely of non-humic materials, hydrophilic, less aromatic as compared to waters with higher SUVA values. Through the biodegradability test, Dissolved organics showed that the quantity of LMW(Low Molecular Weight) less than 1,000 daltons was decreased, HMW(High Molecular Weight) more than 30,000 daltons had a tendency to increase. Large portion of UV$^{254}$ in final treatment effluent was increased of MMW(Medium Molecular Weight). Also, average removal efficiency of DOC was 32% during sewage treatment.

• 한국환경과학회지
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• 제14권2호
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• pp.105-119
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• 2005

The surface sediments inside Songsanpo and Seogwipo Harbors, major harbors of Jeju Island, were collected three times (June, September and December, 2001) and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) recommended by US-EPA as priority pollutants to assess their distribution levels and their biological effects on the marine organisms, and to suggest their possible origins. The concentrations of total PAHs inside Songsanpo and Seogwipo Harbors ranged from 41 to 288 ng/g on a dry weight basis with a mean value of 121 ng/g and from 14 to 268 ng/g with a mean value of 119 ng/g, respectively, and the levels were low as compared with those in other areas of the world. The sedimentary PAHs may be correlated with organic carbon and mud content to some extent. Based on comparisons of individual and total concentrations with effects-based sediment quality guidelines, the potential for the biological effects on the marine organisms were expected to be very low. From the examinations of the four PAH origin indices, such as LMW /HMW (low molecular weight 2-3 ring PAHs over high molecular weight 4-6 ring PAHs), phenanthrene/anthracene ratio, fluoranthene/pyrene ratio, chrysene/benzo[a]anthracene ratio, it can be concluded that the sediment PAH contaminations were ascribed to both of pyrolytic and petrogenic origins.

• 한국물환경학회지
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• 제24권6호
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• pp.682-689
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• 2008

The purpose of this study was to find out the variation between molecular size distribution (MSD) of natural organic matter (NOM) in raw waters after different water treatment processes like conventional process (coagulation, flocculation, filtration) followed by advanced oxidation process (ozonation, GAC adsorption). The MSD of NOM of Suji pilot plant were determined by Liquid Chromatography-Organic Carbon Detection (LC-OCD) which is a kine of high-performance size-exclusion chromatography (HPSEC) with nondispersive infrared (NDIR) detector and $UV_{254}$ detector. Five distinct fractions were generally separated from water samples with the Toyopearl HW-50S column, using 28 mmol phosphate buffer at pH 6.58 as an eluent. Large and intermediate humic fractions were the most dominant fractions in surface water. High molecular weight (HMW) matter was clearly easier to remove in coagulation and clarification than low molecular weight (LMW) matter. Water treatment processes removed the two largest fractions almost completely shifting the MSD towards smaller molecular size in DW. No more distinct variation of MSD was observed by ozone process after sand filtration but the SUVA value were obviously reduced during increase of the ozone doses. UVD results and HS-Diagram demonstrate that ozone induce not the variation of molecular size of humic substance but change the bond structure from aromatic rings or double bonds to single bond. Granular activated carbon (GAC) filtration removed 8~9% of organic compounds and showed better adsorption property for small MSD than large one.

• 한국수산과학회지
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• 제50권6호
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• pp.684-693
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• 2017

We investigated methods for extracting histidine-containing low-molecular-weight (LMW) peptides such as anserine, carnosine and histidine from the edible meat of tuna byproducts. Extracts were treated by several methods including heat treatment ($80^{\circ}C$, 10 min), DOWEX ion exchange (IEC), ultrafiltration (UF), and carboxymethyl (CM)-cellulose column chromatography (IEC+CMC); then the levels of protein, total iron, histidine, carnosine, and anserine were measured. Extracts treated with IEC+CMC using CM-cellulose were analyzed for total iron, protein, histidine, and anserine content, which were $6.27{\pm}0.26mg/mL$, $5.20{\pm}0.21{\mu}g/mL$, 0.80 mg/mL, 0.208 mg/mL, and 4.40 mg/mL, respectively, in yellowfin tuna; and $9.05{\pm}0.82mg/mL$, $4.06{\pm}0.20{\mu}g/mL$, 1.62 mg/mL, 0.012 mg/mL, and 7.28 mg/mL in bigeye tuna. By comparison in IEC-UF treated extracts, protein, total iron, and histidine content decreased by 43%, 73%, and 27% in yellowfin and 0.4%, 54%, and 23% in bigeye tuna, wheres carnosine and anserine content increased by 22% and 17%, respectively. Freeze-dried (FD) extracts exhibited similar trends as non-dried extracts, i.e., dipeptide content increased with purification steps, whereas pro-oxidant (total iron and protein) content decreased. IEC+CMC treated FD extracts had the highest anserine, content, and the greatest reductuion in pro-oxidants.

• 한국물환경학회지
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• 제21권2호
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• pp.125-131
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• 2005

Natural organic matter(NOM) is defined as the complex matrix of organic material and abundant in natural waters. It affects the performance of unit operations for water purification. Several kinds of analytical indicators such as DOC, specific ultraviolet absorbance(SUVA), apparent molecular weight (AMW), fractionation and high performance size exclusive chromatography(HPSEC) have been used to understand characteristics and variations of NOM. This study aims to evaluate the characteristics of NOM in the Geum River system comprising with stream flows and reservoirs. It was identified that SUVA denoting the portion of humic substance in water ranged within 1.60~3.36. Using resin adsorbents, dissolved organic carbon(DOC) was fractionated into three classes: hydrophobic bases(HOB), hydrophobic acids(HOA) and hydrophilic substances(HI). HI dominates in all samples, collectively accounting for more than 62% of the DOC. HOA was the second dominated fraction and it varied considerably but accounted for about 30% of the DOC. The distribution of high molecular weight(HMW) measured by HPSEC being used to determine the molecular weight distribution of aquatic humic substances was 40.1% and 38.7% in reservoir and stream flow, respectively. The distribution of low molecular weight(LMW) in stream flow was 13.2% higher than that in reservoir. And apparent molecular weight less than 1KDa, which include the molecular weight of hydrophilic organic matter, occupied with 69.2% and 68.2% in stream flow and reservoir, respectively. While the molecular weight of 1 to 100 KDa including humic substances ranged with 18.6% and 21.6% in stream flow and reservoir, respectively. Seasonal variation of refractory dissolved organic carbon was similar to that of SUVA.

• 한국육종학회지
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• 제43권5호
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• pp.479-489
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• 2011

Gluten is the main functional component of wheat, and is the main source of the viscoelastic properties in a dough. One of the gluten group is glutenin, which is composed of high molecular weight (HMW) and low molecular weight (LMW) subunits. The HMW glutenin subunits (HMW-GS) have been shown to play a crucial role in determining the processing properties of the grain. They are encoded by the Glu-1 loci located on the long arms of homeologous group one chromosomes, with each locus comprising two genes encoding x- and y-type subunits. The presence of certain HMW subunits is positively correlated with good bread-making quality. The highly conserved N- and C- terminal contaning cystein residues which form interand intra-chain disulphide bonds. This inter chain disulphide bonds stabilize the glutenin polymers. In contrast, the repetitive domains that comprise the central part of the HMW-GS are responsible for the elastic properties due to extensive arrays of interchain hydrogen bonds. In this review, we discuss HMW-GS, HMW-GS structure and gluten elasticity, relationship between HMW-GS and bread wheat quality and genetic engineering of the HMW-GS.

• Plant Breeding and Biotechnology
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• 제6권4호
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• pp.413-425
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• 2018

A previous work developed and identified a new omega-5 gliadin deficient wheat line named O-free by crossing Keumkang and Olgeuru, which is nutritionally quite meaningful in that omega-5 gliadin is one of the known wheat allergens. To verify the characteristics of the O-free, we performed RNA sequencing (RNAseq) analysis of the O-free and the two parent lines (Keumkang and Olgeuru). The results of the similarity analysis with the ESTs for gliadins and glutenins showed that the O-free ESTs had no similarity with the omega-5 gliadin sequences but had similarity to other gliadins and glutenins. Furthermore, mapping results between the raw RNAseq data from the O-free and the omega-5 gliadin sequence showed a clear deletion of the N-terminal sequences which are an important signature of omega-5 gliadin. We also designed specific PCR primers that could identify omega-5 gliadin in the genomic DNA. The results showed that no omega-5 gliadin fragments were detected in the O-free. According to these results, we confirmed that the deficiency of omega-5 gliadin in the O-free is not caused by post-transcriptional or post-translational regulations such as epigenetic phenomena but by a simple deletion in the chromosome. Furthermore, we showed that the low-molecular weight glutenin subunit (LMW-GS) gene in the O-free had a single nucleotide polymorphism (SNP) causing a premature stop codon, resulting in a truncated polypeptide. We expect that the O-free line may serve as an excellent source of wheat that could prevail in the hypo-allergen wheat market, which has recently gained interest world-wide.

• 자원환경지질
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• 제56권1호
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• pp.75-85
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• 2023

The potential sources and spatial distribution of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were investigated in the leaf plants of Al-Zubair city. A total of 14 samples of conocarpus lancifolius plant leaf were collected and analyzed for their heavy metals and PAHs content using inductively coupled plasma mass spectrometry (ICP-MS) and a 7890 Agilent capillary gas chromatograph (GC) respectively. Bioaccumulation factor calculation revealed the highest pollution of heavy metals , due to the activity of a petrochemical in the area. The diagnostic ratio of Ant/(Phe+Ant), BaA/BaA+Chr), In/(In+BghiP), Flu/Pyr, FlA/FlA+Pyr), FlA/FlA+Pyr), ∑LMW/∑HMW are commonly used for determining the origin and source of PAHs in various environmental media. The diagnostic ratio indicated the anthropogenic origin. PAHs with five-to-six membered rings were dominant in the plant leaf, which likely results from anthropogenic activities. The leaves of C. lancifolius have a preponderance of high molecular weight PAHs compared to low molecular weight PAHs, indicating a combustion origin (car exhaust, petroleum emissions, and fossil fuel). C. lancifolius leaves are a reliable indication of atmospheric PAHs absorption. The background level of heavy metals in the city (or the near environment) is in the order of Fe > Cu > Ni > Cr. On the other hand, the bioaccumulation in plant leaves showed greater tendencies as follows: Co>Cd>Zn=As>Cu>Mn>Ni>Pb>Cr>Fe. Cobalt showed high bioaccumulation, indicating strong uptake of Co by plant leaves. These findings point to human activity and car emissions as the primary sources of roadside vegetation pollution in Al-Zubair city.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2230-2245
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• 2023

KANT (KAIST Advanced Nuclear Tachygraphy) is a PWR core simulator recently developed at Korea Advance Institute of Science and Technology, which solves three-dimensional steady-state and transient multigroup neutron diffusion equations under Cartesian geometries alongside the incorporation of thermal-hydraulics feedback effect for multi-physics calculation. It utilizes the standard Nodal Expansion Method (NEM) accelerated with various Coarse Mesh Finite Difference (CMFD) methods for neutronics calculation. For thermal-hydraulics (TH) calculation, a single-phase flow model and a one-dimensional cylindrical fuel rod heat conduction model are employed. The time-dependent neutronics and TH calculations are numerically solved through an implicit Euler scheme, where a detailed coupling strategy is presented in this paper alongside a description of nodal equivalence, macroscopic depletion, and pin power reconstruction. For validation of the steady, transient, and depletion calculation with pin power reconstruction capacity of KANT, solutions for various benchmark problems are presented. The IAEA 3-D PWR and 4-group KOEBERG problems were considered for the steady-state reactor benchmark problem. For transient calculations, LMW (Lagenbuch, Maurer and Werner) LWR and NEACRP 3-D PWR benchmarks were solved, where the latter problem includes thermal-hydraulics feedback. For macroscopic depletion with pin power reconstruction, a small PWR problem modified with KAIST benchmark model was solved. For validation of the multi-physics analysis capability of KANT concerning large-sized PWRs, the BEAVRS Cycle1 benchmark has been considered. It was found that KANT solutions are accurate and consistent compared to other published works.

• The Korean Journal of Pain
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• 제1권1호
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• pp.64-73
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• 1988

Recent studios have shown that narcotic drags produce an unusually intense, prolonged and segmental analgesic action in man whoa injected into the spinal subarachnoid or epidural space (Wang et al, 1979; Behar et al, 1979; Cousins et al, 1979; Magora et a., 1980, Johnston and McCaughey, 1980). Since 1960, many investigators claimed that low molecular weight(LMW) dextran increased the clinical duration of lidocaine(Loder, 1960; Loder, 1962), tetracaine (Chinn and Wirjoatmadja, 1967) and bupivacaine(Kaplan et al, 1975) in man but the mechanism of the action of dextran was unclear. But Curtiss and Scurlock(1979), and Buckled and Fink(1979) claimed that LMW dextran has no effect on the duration of action of bupivacaine in animal studies. The present study was performed to evaluate the clinical efficacy of analgesia by the thoracic epidural injection of morphine and bupivacaine mixture for the relief of pain due to fractured or contused ribs, to evaluate the duration of analgesic effect by the use of the above mixture in a hypertonic solution(dextran 70 or 50% dextrose in water) and to observe the possibility of improvement in the lung function after the pain block. The complications following the pain block were also observed. The 50 single thoracic epidural injections of the mixture were divided into three groups : Group 1(n=15) served as a control group and drags used for the relief of pain were as follows(Mean$\pm$S.D.): morphine($2.13{\pm}1.64\;mg$), 0.5% bupivacaine($3.10{\pm}1.04\;ml$) and 0.9% saline($3.64{\pm}1.11\;ml$). Group 2(n=16) serves as an experimental group and drugs were as follows(Mean$\pm$S.D.): morphine($2.13{\pm}0.72\;mg$), 0.5% bupivacaine($3.06{\pm}0.77\;ml$) and dextran 70($3.75{\pm}1.29\;ml$). Group 3 (n=19) served as an experimental group and drags were as follows(Mean$\pm$S.D.) : morphine($2.42{\pm}0.51\;mg$), 0.5% bupivacaine($3.21{\pm}0.71\;ml$) and 50% dextrose in water($3.58{\pm}1.11\;ml$). The results are were follows: 1) The Dumber of patients who obtained excellent and good analgesic effects following the block were greater in the experimental Croup 2(94%) and Group 3 (90%) than theme of the control Group 1 (80%). 2) The duration of pain relief which lasted more than 3 days after the epidural block was longer in the experimental Group 2 (81%) and Group 3 (75%) than those of the control Croup 1(67%). 3) The pulmonary reserve(FVC%+FEV 1.0%) of 27 cases who were treated by the pain block between 1 and 31 drys following the chest injury was increased to about 13% than those before the block, and that of 13 cases between 32 and 82 days following the chest injury was decreased to about 4% than those before the block. 4) Of the complications following the pain block, there were 5 cased(10%) of nausea within 2 hours following the block, 4 cases(8%) of vomiting after 2 hours following the block, 10 cases(20%) of pruritus after 3~4 hours following the block, 17 cases(34%) of transient urinary retention which tasted 8 to 19 hours, 3 cases(6%) of headache within 2 hoers following the block and 2 cases(4%) of dural puncture. In conclusion, it is suggested that the clinical duration of analgesic effect produced by morphine and bupivacaine mixture can be prolonged by addition of the hypertonic solution to the mixture.