• Title/Summary/Keyword: TPT

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SAFT Equation of State for Vapor-liquid Phase Equilibria of Associating Fluid Mixtures (SAFT 상태 방정식과 회합성 유체 혼합물의 기액 상평형)

  • Chang, Jaeeon
    • Korean Chemical Engineering Research
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    • v.56 no.5
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    • pp.607-624
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    • 2018
  • We review SAFT equation of state (EOS) which is based on TPT theory and statistical-mechanical principles, and confirm that it can be used as a useful tool to predict vapor-liquid phase equilibria of associating fluid mixtures. We examine theoretical structure of PC-SAFT EOS in great detail, and then assess the applicability and performance of the EOS while applying it to various mixtures containing nonpolar components, polar components and associating components in a stage-wise manner. In contrast to the conventional engineering EOS, PC-SAFT EOS can accurately predict nonideal behaviors of those mixtures without using semi-empirical binary interaction parameter. This is because the SAFT theory is based on a rigorous theoretical framework at molecular level which effectively accounts for various intermolecular interactions, and it thus provides substantial benefits in applying the SAFT EOS to complex thermodynamic phenomena of multi-component mixtures.

Analysis of Organotin Compounds in Fish and Shellfish from Guryongpo Harbor (구룡포항 어패류에 함유된 유기주석화합물 분석)

  • Kim, Mee-Ra;Kim, Sung-Hong
    • Korean Journal of Human Ecology
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    • v.14 no.1
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    • pp.209-216
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    • 2005
  • The concentrations of organotin compounds in fish and shellfish from Guryongpo harbor were analyzed. The concentrations of TBT, DBT and MBT in fish were in the range of $15.68{\sim}52.93\;ng/g$(average 28.65 ng/g), $13.95{\sim}72.16\;ng/g$(average 26.99 ng/g) and $37.73{\sim}133.59\;ng/g$(average 85.18 ng/g), respectively. The BT compound concentrations in intestine of fish were higher than those in muscle. Overall ranges of TBT, DBT and MBT concentrations in shellfish were $42.15{\sim}56.13\;ng/g$(average 50.94 ng/g), $34.16{\sim}52.82\;ng/g$(average 42.79 ng/g) and $41.25-72.60\;ng/g$(average 53.71 ng/g), respectively. The BT compound concentrations of shellfish were higher than those of fish. The concentrations of TPT and DPT in fish were $0.47{\sim}3.90\;ng/g$(average 2.33 ng/g) and $ND{\sim}0.56\;ng/g$(average 0.15 ng/g), but MPT was not detected. The concentrations of TPT, DPT and MPT in shellfish were in the range of $10.24{\sim}21.67\;ng/g$(average 17.45 ng/g), $3.32{\sim}4.78\;ng/g$(average 3.91 ng/g) and $0.11{\sim}0.36\;ng/g$(average 0.25 ng/g), respectively. In addition, the MBT ratio was highest among BT compounds, but the TPT ratio was the highest among PT compounds. Taken together, the concentrations of organotin compounds in fish and shellfish from Guryongpo harbor was not higher than those from other harbors in Korea.

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Comparison of Cognitive Task-Directed Motor Control Ability in Younger and Older Subjects (인지적 요소가 포함된 과제 수행 시 젊은 성인과 노인의 동작 조절 비교)

  • Lee, Soo-A;Choi, Jong-Duk
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.1
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    • pp.51-59
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    • 2017
  • PURPOSE: This study compared cognitive task-directed functional motor control ability for reaching and kicking movements in younger and older adults. METHODS: Subjects were divided into two groups of younger and older adults, with 13 subjects in each group. Subjects were required to perform a dual task combining a functional movement and cognitive component. The task consisted of reaching and kicking movements. Participants performed indicated movements when a target appeared on a monitor. The target randomly appeared on the monitor every 10 seconds. The total performance time (TPT), joint angular velocity (JAV), and muscle activation time were used to evaluate motor control ability. RESULTS: There were significant differences in all evaluation factors in a comparison of younger and older adults (p<.05). TPT was significantly shorter in older adults, and JAV and muscle activation time were significantly slower than that in the younger adult group. Although the results for older adults were within the normal range for functional assessment, their motor control abilities were significantly worse for cognitive tasks compared with those of younger adults. CONCLUSION: The results of this study indicated that a motor control assessment tool using a cognitive task would be helpful in assessment of motor control ability in healthy older adults.

Evaluation of Applicability of Steel-pipe Energy Piles Through Thermal Performance Test (TPT) (현장 열성능 평가시험을 통한 강관 에너지파일의 적용성 평가)

  • Lee, Seokjae;Choi, Hangseok
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.18 no.2
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    • pp.1-9
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    • 2022
  • A novel steel-pipe energy pile is introduced, in which the deformed rebars for main reinforcing are replaced with steel pipes in a large diameter cast-in-place energy pile. Here, the steel pipes act as not only reinforcements but also heat exchangers by circulating the working fluid through the hollow hole in the steel pipes. Under this concept, the steel-pipe energy pile can serve a role of supporting main structures and exchanging heat with surrounding mediums without installing additional heat exchange pipes. In this study, the steel-pipe energy pile was constructed in a test bed considering the material properties of steel pipes and the subsoil investigation. Then, the thermal performance test (TPT) in cooling condition was conducted in the constructed energy pile to investigate thermal performance. In addition, the thermal performance of the steel-pipe energy pile was compared with that of the conventional large diameter cast-in-place energy pile to evaluate its applicability. As a result, the steel-pipe energy pile showed 11% higher thermal performance than the conventional energy pile along with much simpler construction processes.

찰가자미(Microstomu sachne)의 알과 난황 자어의 생존율에 미치는 유기주석화합물의 독성

  • 전미정;이미희;임한규;이종관;이수형;전중균
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.10a
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    • pp.154-155
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    • 2000
  • 해양생물들의 부착방지를 위해 선박 또는 어망에 사용되는 유기주석화합물(organotin compounds: OTC)의 하나인 TBT (tributyltin)는 환경적으로 영향을 주는 농도에서 여러 수중 생물의 발생단계와 자어기와 같은 어류의 초기생활사에 영향을 끼치기 쉽다 (Bryan and Gibbs, 1991). 또한, TBT와 함께 사용되는 TPT (triphenlyti)는 수중에서 수산생물의 체내에 빠르게 축적되는 반면에 배출은 천천히 일어난다(Jarvinen et al., 1988). (중략)

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Tributyltin chloride(TBTC)와 Triphenyltin chloride(TPTC)에 노출된 넙치(Paralichthys olivaceus) 치어에 있어서의 RT-PCR에 의한 유전자 증폭반응

  • 최윤실;함승협;진덕희;전중균
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.373-374
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    • 2000
  • Tributylin(TBT)과 Triphenyltin(TPT) 같은 유기주석화합물은 선박, 어망, 어구등 방오도료의 소재로 사용되어 왔으나 최근 해양생물에게 미치는 독성 때문에 세계 각 국에서도 그 사용을 금지하고 있다. 우리 나라의 경우, 한국 해양연구소가 내분비 교란물질(환경호르몬)의 농도를 조사한 결과 다른 지역에 비해 내만 지역에서의 오염도가 다소 높다고 보고되어 있다. 내만지역의 경우는 파도가 약하여 양식장이 많으므로 양식어류가 TBT와 같은 유기주석 화합물에 노출될 가능성은 매우 높다. (중략)

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Effect of Alternate Bias Stress on p-channel poly-Si TFT's (P-채널 poly-Si TFT's의 Alternate Bias 스트레스 효과)

  • 이제혁;변문기;임동규;정주용;이진민
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.489-492
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    • 1999
  • The effects of alternate bias stress on p-channel poly-Si TPT's has been systematically investigated. It has been shown that the application of alternate bias stress affects device degradation for the negative bias stress as well as device improvement for the positive bias stress. This effects have been related to the hot carrier injection into the gate oxide rather than the generation of defect states within the poly-Si/SiO$_2$ under bias stress.

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In vitro and in vivo Responses of MFO Systems in Olive Flounder (Paralichthys olivaceus) Exposed to TBT and TPT for Short-term Period (유기주석화합물에 단기간 노출시킨 넙치 간장 약물대사효소의 in vivo 및 in vitro 반응)

  • 전중균;이지선;전미정;심원준;임한규
    • Korean Journal of Environmental Biology
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    • v.22 no.1
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    • pp.177-183
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    • 2004
  • Cytochrome P45O (CYP) contents and 7-ethoxyresorufin-O-deethylase (EROD) activity were determined in hepatic microsome of olive flounder (Paralichthys olivaceus) exposed to tributyltin chloride (TBTC), tributyltin oxide (TBTO), and triphenyltin chloride (TPTC). In addition, effects of in vivo (intraperitoneal injection of 7.5 mg $kg^{-1}$ BW) exposure of flounder to TPTC on CYP, NADPH cytochrome c reductase, NADH cytochrome b5 yeductase and EROD levels were measured. In in vitro exposure of hepatic microsome to organotins, TBTC, TBTO and TPTC reduced CYP contents and inhibited EROD activity. The TPTC was the strongest inhibitor, which is followed by TBTO and TBTC. The degree of inhibition, especially EROD acitivity, depended on the exposure duration. In addition, all the target enzymes in flounder were inhibited by TPTC with the in vivo exposure to TPTC. As EROD activity was the most sensitive to the inhibitions and demonstrated good reproducibility of the results, it could be used as a helpful tool toy monitor effects of organotin compounds on mixed funciton oxygenase system in marine fish.

Toxicity of TBT and TPT Compounds on the Survival of Rotifer (Brachionus plicatilis) (Rotifer(Brachionus plicatilis)의 생존율에 미치는 tributyltin (TBT)과 triphenyltin (TPT)의 독성)

  • 전중균;이미희;이지선;이경선;심원준;신영범;이수형
    • Korean Journal of Environmental Biology
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    • v.21 no.2
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    • pp.158-163
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    • 2003
  • This study was conducted te evaluate the effect of organotin compounds on rotifer(Brachionus plicatilis), which is important as food organism of aqua-cultured fish and shellfish. To evaluate the texicities of tributyltin compounds such as tributyltin chloride (TBTC), tributyltin oxide (TBTO), tributyltin acetate (TBTA) and tributyltin benzoate (TBTB), and triphenyltin compounds such as triphenyltin chloride (TPTC), triphenyltin fluoride (TPTF), triphenyltin hydroxide (TPTB), the survival rates of rotifer exposed to these compounds were measured as the 96 hr-$LC_{50}$. Exposed concentrations Were from 0.5 to 8 bbp depending on compounds. Based on 96 hr-$LC_{50}$ Value, the Order of toxicity in TBTs was TBTA(1.1 ppb)>TBTC (2.0)>TBTB (3.3)>TBTO(5.6), and that in TPTs was TPTF (1.0)$\geq$TPTC(1.1)>TPTH(1.6). Triphenyltin compounds were slightly higher toxic than tributyltins. The toxicity is likely to depend on alkyl or aryl group other than halogen or the other substituted radicals.