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Effect of Coating Materials for Steel on the Threshold of Corrosive Amount of Airborne Chlorides and the Evaluation of Their Corrosion Speeds (강재마감별 부식개시 임계 비래염분량 및 부식속도 평가)

  • Cho, Gyu-Hwan;Lim, Myung-Hyun;Park, Dong-Cheon
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.2
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    • pp.143-151
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    • 2015
  • Many studies have investigated the airborne chlorides that can weaken the overall durability of the concrete structures due to the corrosion of steel materials, but most of the studies have aimed to examine weathering by exposing various construction materials to the actual oceanic environment. However, with the exposure test, it was difficult to find the threshold of precise corrosive amount of airborne chlorides due to diverse deteriorating environmental factors such as ultraviolet ray, acid rain, floating material from industrial pollution as well as airborne chlorides. Therefore, in this study, an airborne chloride simulator was set up, in oder to conduct a corrosion accelerating test for steels coated by five different finishing materials. As results, it was found that the corrosion began to be observed at 0.580.73mg/dm2 for no-coated steel, at 7.898.46mg/dm2for urethane-coated steel, at 57.9569.48mg/dm2 for red lead-coated steel, and at 80.7389.35mg/dm2 for stainless-coated steel, respectively. Hence, these specific data can be considered as the threshold ranges of corrosion for each coating material for steel.

Preparation of Core-Shell Structured BaTiO3 Powder Via Coating of Cr2O3 and Mn2O3 (Cr2O3 및 Mn2O3의 코팅에 의한 Core-Shell 구조의 BaTiO3 분말 제조)

  • Kwon, Byung-Soo;Lee, Hye-Un;Jang, Jung-Yoon;Lee, Sang-Kil;Chung, In Jae;Cho, Young-Sang;Park, Tae-Jin;Choi, Guang-Jin
    • Korean Chemical Engineering Research
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    • v.46 no.1
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    • pp.99-105
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    • 2008
  • Core-shell structured BaTiO3 powders were produced via nano-coating of Cr2O3 and Mn2O3 to barium titanate powder system for MLCCs. From preliminary experiments, the optimal solution reaction condition employing using KMnO4, K2Cr2O4 and sulfur was established. Not only powders of Cr2O3 and Mn2O3 were synthesized but also their coating on BaTiO3 powders were peformed under the same reaction condition. The coating was carried out in two ways, one-step and two-step, and its results were characterized for comparison. Conclusively speaking, two oxide additives were coated onto the BaTiO3 powder surface with high quality and excellent reaction yield even under mild condition, which indicates that the contents as well as the properties of additive shell layer can be precisely controlled with rather ease.

LOCAL ANESTHESIA IN CHILDREN USING JET INJECTION INSTRUMENT (분사식 주사기를 이용한 소아환자의 국소마취)

  • Lee, Jae-Chun;Kim, Dae-Eop;Lee, Kwang-Hee;Kim, Seong-Hyeong;Yang, Kye-Sik
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.4
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    • pp.633-637
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    • 2001
  • Local anesthesia procedure in pediatric dentistry using needle-tipped syringes is stressful and painful for the child patients The Syrijet Mark II (Mizzy Inc. USA) is a jet injection instrument, which uses high pressure to propel fluids into soft tissue without the use of a hollow neeldle, so it seems to be able to reduce the injection phobia of the child patients. The authors compared the Syrijet with the conventional syringe by assessing the pain level after local anesthetic procedures using CAS(color analogue scale) which was developed from VAS(visual analogue scale). The result showed that the pain was reduced by the use of syrijet. The advantages of syrijet were no use of neeldes, the reuse of the anesthetic cartridge, and the safety to nerves and vessels. The disadvantages were the large size, the high price, and the need of skill to use.

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Preparation and Adhesion of One Part Room Temperature Curable Alkoxy Type Silicone Sealant (일액형 알코올형 실리콘 실란트의 제조 및 접착 물성)

  • Kim, Dae-Jun;Park, Young-Jun;Kim, Hyun-Joong;Lee, Bong Woo;Han, Jae Chul
    • Journal of Adhesion and Interface
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    • v.2 no.4
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    • pp.1-9
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    • 2001
  • Silicone sealants are composed of polymer, plasticizer, crosslinker, catalyst and filler. Types and compositions of components are effected on sealant performances. In recent, use of alkoxy type silicone sealant increased due to environmental advantage. In this study, we investigated effects of component types and ratios on one-part room temperature curable alkoxy type silicone sealant preparation and adhesion properties. Alkoxy type silicone sealants were prepared with various PDMS (polydimethylsiloxane) viscosities. In addition, the effect of plasticizer, crosslinkers, and catalyst on sealant obtained from by mixture of PDMS viscosities of 20000 and 80000 was investigated. Reaction temperature on change of mixing time was observed, and then proper crosslinking systems were found. Adhesion (properties) of silicone sealants were measured. In the sealants preparation, stable reaction was achieved by adjusting composition variance ratio in the sealant mixture temperature below 40C. The adhesion properties of sealant differ from substrate composition. The order of adhesion strength was glass/glass > glass/aluminum > aluminum/aluminum system. The elongation of sealant was increased as polymer viscosity and plasticizer content increased. The strength was increased as crosslinker and plasticizer decreased, while catalyst increased.

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Anticancer Activities by Combined Treatment of Red Ginseng Acidic Polysaccharide (RGAP) and Anticancer Agents (홍삼산성다당체 (RGAP)와 항암제의 병용투여에 의한 항암시너지 효과)

  • Kwak, Yi-Seong;Kim, Young-Sook;Shin, Han-Jae;Song, Yong-Bum;Park, Jong-Dae
    • Journal of Ginseng Research
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    • v.27 no.2
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    • pp.47-51
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    • 2003
  • Synergistic anticancer activities of red ginseng acidic polysaccharide (RGAS) showing immunomodulatory activity were evaluated by combined treatment with anticancer agents such as Cyclophosphamide (CY) or 5-Fluorouracil (5-FU) in experimental tumor models. The combined treatment of RGAP (100 mg/kg) and CY (3 mg/kg) exhibited 71% of survival rate in lift span of sarcoma 180-bearing mice, while single treatment of RGAP (100 mg/kg) and CY (3 or 10 mg/kg) exhibited 43, 14 and 43% of survival rates, respectively. In addition, when RGAP (100 mg/kg) was administered in combination with 5-FU (2.5 mg/kg) to sarcoma 180 tumor-bearing mice, higher survival rate was found when compared with RGAP or 5-FU treatment alone. Moreover, tumor weights in LL/2 lung carcinoma-bearing mice treated combined with RGAP (100 mg/kg) and 5-FU (5 or 10 mg/kg) was obviously decreased when compared with 5-FU alone. These results suggest that clinical trials of RGAP as an adjuvant in cancer chemotheraphy can be higly feasible.

Changes in Phosphatase Activity of the Mouse Uterus during the Estrous Cycle (發情週期에 EK른 생쥐子宮의 Phosphatase 活性의 變化에 관하여)

  • Kim, Moon-Kyoo;Kim, Sung-Rye;Cho, Wan-Kyoo
    • The Korean Journal of Zoology
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    • v.23 no.2
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    • pp.61-68
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    • 1980
  • Quantitative analysis of the activities of transport ATPases as well as alkaline phosphatase of the mouse uterus was carried out during the estrous cycle. Even though the proportional patterns of the enzyme activities were similar each another between the stages of estrous cycle, the absolute activities of the enzymes except K+-dependent and Na+, K+-activated ATPases at the time of estrus were significantly (p<0.025) higher than that at any other time of the estrous cycle. That is, the activities of K+-dependent and Na+, K+-activated ATPases were negligible during the period of time from diestrus to estrus while the little activities (0.04 sim 0.05muM/mg protein/hr in average, 6sim7% of the total enzyme activity) of these enzymes appeared at the time of metaestrus. On the other hand, at the time of estrus, the activities of Mg++-dependent phosphatase, transport ATPase and alkaline phosphatase were rapidly and tremendously increased to be 0.69 (35%), 0.42 (21%) and 1.58 (79%), respectively. The activity of alkaline phosphatase was in the range of 0.60 sim 1.58 (79 sim 90%) and predominant throughout the estrous cycle. The activity of Mg++-dependent alkaline phosphatase was estimated as 12 sim 16% of the total enzyme activity. Therefore, it is assumed likely that K+-dependent and Na+, K+-activated ATPases are not the main factors to control the fluid accumulation at the time of estrus, but may be the factors to reabsorb the luminal fluid into the uterine epithelium at the time of metaestrus, and that Mg++-dependent phosphatase, transport ATPase and alkaline phosphatase must be closely involved in the secretion of luminal fluid from the epithelial cells of the mouse uterus.

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Biological Activity of Recombinant Human Thrombopoietin (유전자 재조합 인간의 Thrombopoietin의 생리활성)

  • Kim, Boing-Soon;Naidansuren, Purevjargal;Min, Kwan-Sik
    • Journal of Life Science
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    • v.17 no.11
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    • pp.1497-1504
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    • 2007
  • To investigate the function and secretion of human thrombopoietin (TPO) in mammalian cells, hTPO cDNA was cloned using human liver cDNA, and recombinant hTPO (rec-hTPO) was produced in CHO cell lines. In addition, six N-linked glycosylation sites were substituted for Ala to elucidate the role of each carbohydrate chain. To analyze the biological activity, rec-hTPO protein was injected subcutaneously. Blood was withdrawn for platelet determination. The metabolic clearance rate (MCR) was also analyzed at the 1, 4, 10 and 24 hr after tail vein injection. Wild-type TPO (WT) was efficiently secreted into the medium. However, a hTPO mutant with 116 deleted nucleotides detected by PCR cloning was not secreted. The N-linked glycosylation sites had nearly the same expression quantity as rec-hTPO WT apart from mutants 3 and 4. The glycosylation site of mutant 4 appeared to be an indispensable site for hTPO secretion. Also characterized was the biological activity through an injection with rec-hTPO (10 ng) to ICR mice (7 weeks). The result of the blood analysis showed a considerable increase in the platelet number six days after He injection. To analyze the pharmacokinetics, rec-hTPO was injected into the tail vein (5 ng). The result was 200 pg/ml 1hr after this injection. Following this, it dramatically decreased and virtually disappeared 10 hours after the injection. Thus, rec-hTPO may be a treatment for thrombopenia by the production of the high active rec-hTPO. In addition, hTPO can permit the development of potent new analogues that stimulate the platelet value.

Cloning and Functional Analysis of Gene Coding for S-Adenosyl-L-Methionine Synthetase from Streptomyces natalensis (Streptomyces natalensis로부터 S-adenosyl-L-methionine synthetase 유전자의 클로닝 및 기능분석)

  • Yoo, Dong-Min;Hwang, Yong-Il;Choi, Sun-Uk
    • Journal of Life Science
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    • v.21 no.1
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    • pp.96-101
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    • 2011
  • S-Adenosyl-L-methionine synthtase (SAM-s) catalyzes the biosynthesis of SAM from ATP and L-methionine. SAM plays important roles in the primary and secondary metabolism of cells. A metK encoding a SAM-s was searched from Streptomyces natalensis producing natamycin, a predominantly a strong antifungal agent, inhibiting the growth of both yeasts and molds and preventing the formation of aflatoxin in filamentous fungi. To obtain the metK of S. natalensis, PCR using primers designed from the two highly conserved regions for metK genes of Streptomyces strains was carried out, and an intact 1.2-kb metK gene of S. natalensis was cloned by genomic Southern hybridization with PCR product as a probe. To identify the function of the cloned metK gene, it was inserted into pSET152ET for its high expression in the Streptomyces strain, and then introduced into S. lividans TK24 as a host by transconjugation using E. coli ET12567(pUZ8002). The high expression of metK in S. lividans TK24 induced actinorhodin production on R5 solid medium, and its amount in R4 liquid medium was 10-fold higher than that by exconjugant including only pSET152ET.

Kinematic analysis of scapular movements during flat first serve depending on tape application (테니스 플랫서브시 키네시올로지 테이핑 적용에 따른 어깨뼈의 운동학적 분석)

  • Kim, Taegyu;Choi, Hokyung
    • Journal of the Korea Convergence Society
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    • v.11 no.9
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    • pp.325-332
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    • 2020
  • This study aimed to identify the difference of scapular movements between tennis players with and without shoulder impingement syndrome(SIS) and to verify the effect of kinesiology taping applied to scapular. A total of 15 players were categorized in SIS group(n=7) and control(CON) group(n=8). The scapular movements evaluated using 3-dimensional motion analysis in the 5 events of the flat first serve before and after the application of taping. The male of SIS group(-7.31±1.19° and -5.28±1.08°, respectively) had tilted scapular more anteriorly compared to CON group(-0.98±5.38° and -0.44±3.52°, respectively) at the maximally humeral external rotation and the impact(Z=-2.309, p=.021 and Z=-2.309, p=.021, respectively). The scapular(-8.11±2.57°) of female in SIS group tilted more anteriorly than that of CON(-0.97±3.31°) group at the maximally humeral external rotation(Z=-2.121, p=.034). But the scapular movements had no statistical differences between before and after the application of taping.

The Study on Automatic Temperature Transmission System for the Heating pipe at Home (가정식난방배수관내의자동온도송신장치에대한연구)

  • Park, Chul-Min;Jo, Heung-Kuk;Lee, Hoon-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2641-2646
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    • 2009
  • The more growing on home automation system at automatic control, the more efficiency required for energy consumption and for recycling energy in near future. Heating is essential in general apartment. Heating method is two types in apartment. One uses electricity, and other one uses warm water. If use electricity, is not efficient by rise of electric charges. But, It can reduce much in expense aspect, if use warm water. When use warm water, temperature of warm water is not equal from all pipe parts. Therefore, indoor tempera can be unequal with set point. Solution of these problems is as following. Temperature sensor in warm water attach pipe. The measured temperature transmits by real time. Temperature of warm water controls in receiver side. In this paper, we propose an automatic temperature transmission system for the heating pipe at home, that is a low-power based, and supply the energy source from a small AC motor resided in bottom cement mortal. The proposed system is used in power mechanism from a collision process of water-jet using propeller water-difference and also designed a CPU module by Atmega8 at ATMEL co., Inc. and a communication module by CC1020 at Chipcon co., Inc.