• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.65-74
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• 2000

This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulps(alkaline sulfite-Na2S2O4 pulp) were bleached with the various kinds of bleaching agents. And physical properties of bleached pulps were tested. The results of this study were as follows; 1, The proper conditions of chlorine sequence were determined to be 4% concentration of chlorine 25$^{\circ}C$ of reaction temperature and 50 minutes of reaction time. 2. For calcium hypochlorite sequence the proper conditions of chemical concentration reac-tion temperature and reaction time were 3% 25$^{\circ}C$ and 20 minutes respectively. 3. For chlorine dioxide sequence the proper conditions were 1% concentration of chlorine dioxide 70$^{\circ}C$ of reaction temperature and 2hr. of reaction time. 4. The proper conditions of hydrogen peroxide sequence were 1.5% concentration of hydro-gen peroxide 70$^{\circ}C$ of reaction temperature and 1hr. of reaction time respectively. 5. When the rice-straw chemical pulp were bleached with four kinds of bleaching agents methioned above in the proper conditions respectively brightnesses were the order of chlorine dioxide calcium hypochlorite, chlorine, hydrogen peroxide. And strengthes of pulps bleached with chlorine dioxide and hydrogen peroxide were higher than those of pulps bleached with other bleaching agents.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.259-264
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• 2006

The separation and purification of $TaCl_5$is indispensable in the synthetic process of $TaCl_5$by chlorination of tantalum oxide. The reaction products are mainly $TaCl_5$, $NbCl_5$, $TiCl_4$ and $FeCl_2$. However, we need to separate $TaCl_5/NbCl_5$ mixture from the reaction product, because $TaCl_5$ and $NbCl_5$ are easily separated each other by distillation or hydrogen reduction process. In this work, a comparison study was carried out between direct sequence and indirect sequence to obtain $TaCl_5/NbCl_5$ mixture from the reaction product by removing light component, $TiCl_4$ and heavy component, $FeCl_2$ using two distillation columns. It was concluded that the direct sequence gave better results than indirect sequence in the aspect of initial capital costs and the associative operating costs.

• Fibers and Polymers
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• v.2 no.2
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• pp.86-91
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• 2001

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) [copoly(ET/CPT)] was prepared using poly(ethylene terephthalate) (PET) as a flexible spacer, terephthalic acid (TPA), and chlorohydroquinone diacetate (CHQDA). All reactions involved in the copolymerization were investigated using some model compounds: TAP was used for acidolysis, diphenylethyl terephthalate (DPET) for interchange reaction between PET chains, and 야-o-chlorophenyl terephthalate (DOCT) and di-m-chlorophenyl terephthalate (DMCT) for interchange reaction between PET and rigid rodlike segments. Activation energies obtained for the acidolysis of PET with TPA and for interchange reaction of PET with DPET, DOCT, and DMCT were 19.8 kcal/mol, 26.5 kcal/mole, and 45.9 kcal/mole, respectively. This result supports that the copolymerization proceeds through the acidolysis of PET with TPA first and subsequent polycondensation between carboxyl end group and CHQDA or acetyl end group, which is formed from the reaction of CHQDA and TPA. Also, it was found that ester-interchange reaction can be influenced by the steric hindrance. Copoly(ET/CPT)s obtained has ethylene acetate end groups formed from acetic acid hydroxy ethylene end groups and showed almost the random sequence distribution for all compositions.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.139-142
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• 2005

Most expressed HLA(human leukocyte antigen) loci exhibit a remarkable degree of allelic polymorphism, which is derived from sequenceing differences predominantly localized to discrete hypervariable regions of the amino-terminal domain of the molecule. In this study, the HLA-DRB1 genotypes were determined in twenty students using the PCR-SSP (polymerase chain reaction-sequence specific primer) technique. Two specific primer pairs in assigning the DRB1 gene were used. The results of PCR-SSP, the $HLA-DRB1^{\ast}0101$ primer detected nine and $HLA-DRB1^{\ast}1501$ primer detected three people. This study shows that the PCR-SSP technique is relatively simple, fast and a practical tool for the determination of the HLA-DRB1 genotypes. Moreover, these genotype frequency results of the HLA DRB1 gene could be useful for database study before being applied to individual identification and transplantation immunity.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.113-117
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• 1997

Simple sequence repeats (SSR) are widely dispersed throughout eukaryotic genomes, highly polymorphic, and easily typed using polymerase chain reaction (PCR). The objective of this study was to determine the polymorphism of different Chlamydomonas reinhartdtii strains and to determine the mode of inheritance of the SSR locus in Chlamydomonas. A genomic DNA library of C. reinhardtii was constructed and screened with a radiolabeled $(AC)_{11}$ probe for the selection of (CA/GT)n repeat clone. Selected clone was seqeuenced, and PCR primer set flanking (CA/GT)n sequence was constructed. PCR was used to specifically amplify the SSR locus from multiple isolates of C. reinhardtii. The locus was polymorphic in some of the C. reinhardtii isolates. However, the locus was amplified only 4 of 6 isolates of C. reinhardtii, not in other 2 isolates of C. reinhardtii, suggesting that this locus is not extensively conserved. A simple Mendelian inheritance pattern was found, which showed 2:2 segregation in the tetrads resulting from a cross between C. reinhardtii and C. smithii. Our results suggest that this simple sequence repeat DNA polymorphism will be useful for identity testing, population studies, linkage analysis, and genome mapping in Chlamydomonas.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.94-97
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• 2008

The human leukocyte antigen (HLA) is the name of the major histocompatibility complex (MCH) in humans. The superlocus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6. and encode cell surface antigen-presenting proteins and many other genes. HLA class I antigen (A, B & C) present peptides from inside the cell. These peptides are produced from digested proteins that are broken down in the lysozymes. Most expressed HLA loci exhibit a remarkable degree of allelic polymorphism, which derives from sequence differences predominantly localized to discrete hypervariable regions of the amino terminal domain of the molecule. In this sutdy, the HLA-A genotypes were determined in twenty students unrelated koreans using the PCR-SSP (Polymerase Chain Reaction-Sequence Specific Primer) technique. Several specific primer pairs in assigning the HLA-A gene were used (A*0201, A*33, A*2401). The results of PCR-SSP, the HLA-A*0201 primer was detected eleven (55%), the HLA-A*33 were detected seven (35%) and the HLA-A*2401 were detected seven (35%). This study shows that the PCR-SSP technique is relatively simple, fast and a practical tool for the determination of the HLA-A genotypes.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.147-150
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• 2007

Most expressed HLA (human leukocyte antigen) loci exhibit a remarkable degree of allelic polymorphism, which derives from sequence differences predominantly localized to discrete hypervariable regions of the amino terminal domain of the molecule. In this study, the HLA-B genotypes were determined in twenty students unrelated koreans using the PCR-SSP (polymerase chain reaction-sequence specific primer) technique. Several specific primer pairs in assigning the HLA-B gene were used ($B^{\ast}4001/4007$, $B^{\ast}4901/5001/4501$, $B^{\ast}3701$, $B^{\ast}5801$). The results of PCR-SSP, the HLA-B3701 primer was detected one (5%), the $HLA-B^{\ast}5801$ were detected four (20%), the $HLA-B^{\ast}4001/4007$ were detected nineteen (95%) and the $HLA-B^{\ast}4901/5001/4501$ were detected twenty. This study shows that the PCR-SSP technique is relatively simple, fast and a practical tool for the determination of the HLA-B genotypes. Moreover, these results genotype frequency of the HLA-B gene could be useful for database study before being applied to individual identification and transplantation immunity.

• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.1-7
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• 2008

Purpose: Implicit motor learning is the capacity to acquire skill through physical practice without conscious awareness of what elements of performance improved. This study investigated whether subacute stroke patients can implicitly learn a perceptual-motor task. Methods: We recruited 12 patients with subacute stroke and 12 age-matched controls. All participants performed a perceptual-motor task that involved pressing a button corresponding with colored circles (blue, green, yellow, red) on a computer screen. The task consists of 7 blocks composed of 10 repetitions for a repeating 12-element sequence (total 120 responses). Results: Both groups demonstrated significant improvement in acquisition performance. Reaction times deceased in both groups at similar rate within the sequential block trials (2-5 blocks), and reaction times increased at a similar rate when the task paradigm was transferred from the sequential block trial to the random block trial (5-6-7 blocks). Conclusion: The results of this study suggest that patients with sub-actue stroke can implicitly learn a perceptual motor skill. Although explicit instructions should be used to focus the learner's attention rather than provide information about the task, the application of implicit motor learning strategies in the rehabilitation setting may be beneficial.

• Journal of Life Science
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• v.8 no.6
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• pp.673-680
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• 1998

Adenosine deaminase gene from Nocardioides sp. J-326TK was cloned by polymerase chain reaction using primers (PI, PII and PIII) constructed from the highly conserved amino acid sequences among Escherichia coli, mouse and human. A PCR product of about 800bp, as expected from the sequence of E. coli adenosine deaminase gene, was obtained from Nocardioides sp. J-326TK chromosomal DNA double-digested with EcoRI and Pst I. DNA sequencing of the PCR product after cloning into pT7Blue T-vector shows 99.5% and 98.9% homologies in nucleotide and amino acid sequences, respectively, with the E. coli adenosine deaminase whereas 59.5% and 46.8% homologies with the human adenosine deaminase, indicating the evolutionarily relationship of these organisms.

• The Mathematical Education
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• v.42 no.5
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• pp.707-723
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• 2003

Teaching the notion of limit of the sequence in high school mathematics needs special attention and accurate teaching methods, for it is one of the most important bases of the advanced mathematics. Therefore it is necessary for high school students to have the right understanding of the notion of limit of the sequence. In this paper, we survey several teaching methods of the notion of limit of the sequence in high school mathematics and introduce a new method using Excell program. Also through questionnaire survey we discuss and analyse students' reaction when they learn the notion of limit of the sequence. And based on that, we suggest a method that would be believed to improve the students' understanding for the notion of limit It should be also notified that questionnaire survey was performed in order to find out which method would be appropriate to teach the notion of limit of the sequence, and that the survey result was fully reflected in the guideline that suggested.