• 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.

• The Journal of Korean Physical Therapy
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• v.19 no.1
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• pp.67-78
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• 2007

Purpose: The purpose of this study were to examine the anti-hyperalgesic effects of combination of electroacupuncture and microcurrent on anti-hyperalgesia in local hyperalgesia zone. Methods: It used 24 rats for experiment, divided them into control group, electroacupuncture group (EA group), microcurrent group (MC group), combination of electroacupuncture with microcurrent (EA+MC group), caused hyperalgesia by injecting ${\lambda}-carrageenan$ into hindpaw. Thickness of hindpaw, mechanical pain threshold (MPT), thermal pain threshold (TPT), noxious flexion withdrawal reflex (NFR) and somatosensory evoked potential (SEP) were measured immediately after induction, at 24 hours, 48 hours and 72 hours after induction. The electrical stimulation was given once a day for three days, 20min per session. Results: Change of thickness, MPT, and TPT showed significant difference in all groups compared to control group. In particular, there were remarkable difference in EA+ME group. In particular there were remarkable differences in EA group and EA+MC group. Change of NFR(% threshold, % reaction time, % RMS) and SEP showed mainly significant differences in EA group and EA+ME group compared to control group. In particular, there were remarkable difference in EA+ME group. Conclusion: The above results suggest that appropriate combination of microcurrent with electroacupuncture for pain control will be very desirable.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.3
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• pp.424-435
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• 2022

Aesthetic impression, structural stability, functionality during exercise, freedom of movement and physiological suitability should be considered when developing aquarobic wear for middle-aged women. We conducted a visual evaluation of the commercial aquarobic wear of the five brands (ARENA, TURN, RALLY, RENOMA and ELLE) with the highest market share and selected three items: one-piece type (OPT); two-piece type (TPT) and whole-body type (WBT). These are the most worn types of aquarobic wear for each brand. The G4 showed the best results in appearance evaluation of the shoulder strap width, front neckline, armhole line, side hip line and short pants length in the OPT category. The TPT had better ratings as the shoulder strap was located in the center of the shoulder, and the front and the back necklines were not too deep. The five items of WBT clothing received similar ratings for each element, so it is considered that the advantages are evenly distributed. No single design was a clear favorite. Based on the above results, continuous research on the development of aquarobic wear that is more suitable and preferable for middle-aged women should be conducted.

• Journal of the Korean Geotechnical Society
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• v.40 no.1
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• pp.55-63
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• 2024

In this study, a thermomechanical numerical model was developed to evaluate the stability of energy slabs. First, a wall-type energy slab was installed in a residential underground parking lot, and thermal performance tests were conducted. Based on the tests, a numerical thermohydraulics model of the energy slab was developed to accurately simulate the thermal behavior in thermal performance tests. Finally, utilizing the temperature data acquired using the developed model, a thermomechanical numerical model of the energy slab was established. The thermomechanical model was then used to simulate the thermal stresses induced by operating the energy slab. The results demonstrated a maximum thermal stress of 5,300 kPa, which highlights the need to utilize cement mortar with sufficient tensile strength to realize stable operation of the energy slab.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.767-771
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• 1999

Poly(ester-imide)(PEI) for the electrical insulation coating was synthesized and evaluated with one-step method as well as two-step method. For the synthesis of poly(ester-imide), imide repeat unit of N,N'-(4,4'-diphenylmethane) bistrimellitimide(DID) was initially made from trimellitic anhydride(TMA) and methylene dianiline(MDA), followed by the second stage reaction of esterification. One-step reaction was performed by reaction of TMA, MDA, dimethyl terephthalate(DMT), ethylene glycol(EG), and 1,3,5-tris-(2-hydroxy ethyl) isocyanurate(THEIC) in m-cresol solvent at a time. The synthesized poly(ester-imide) was cured with xylene, P-5030K(phenol-formaldehyde resin), TK-8(TDI type blocked polyisocyanate) and tetrapropyltitanate(TPT). It was found that the content of hydroxyl group, amount of DMT, and imide repeat unit played important role for the properties of electrical insulation coating film.

• Journal of Food Hygiene and Safety
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• v.17 no.3
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• pp.137-145
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• 2002

Tributyltin compounds have been increasingly used in the form of plastic stabilizers, catalytic agents, industrial agricultural biocides, antifouling paint, and pesticides. Among these organotin compounds, large amounts of tributyltin(TBT) and triphenyltin(TPT) have been used as antifouling agents because they have a superior ability to prevent marine organism from being encrusted on ship bottoms and in culturing nets. Environmental pollution by these organotin compounds in the aquatic environment were undertaken. The international maritime Organization's established a provisional tolerable daily intake(TDI) of 1.6[micro]g TBTO/kg/ B.W. The Food and Agiculture Organization (of the United Nations)/world Health Organization's (FAO/WHO) proposed a TDI of 0.5ug TPT/kg BW/d. This study is conducted monitoring of TBT on seafoods in Korea and risk assessment for exposure on TBT in seafoods. Total hazard index(using Reference Dose : 0.3 ug TBTO/kg B.W/day) of intake exposure on seafoods is 0.04 as the 50th percentile, 0.08 as the 95th percentile. This value is estimated by Monte-Carlo simulation using Crystal Ball(Decisioneering Co., 2001).

• The Korean Journal of Malacology
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• v.12 no.2
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• pp.123-131
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• 1996

진해만 바위해안 조간대에 서식하는 뿔소라과 2종, 대수리(Thais clavigera)와 뿔두드럭고둥(T. luteostoma), 에서 수컷의 성징이 암컷에게서 발현되는 임포섹스 현상을 조사하였다. 임포섹스는 전 조사정점에서 100% 나타나고 있었으므로 본 조사에서 수컷의 성징을 보이지 않은 암컷은 발견할 수 없었다. 임포섹스의 강도를 나타내는 상대 성기 길이 지수(relative penislength index: RPL)는 34.7%에서 81.1%의 범위에 있었다. 특히 마산만 안쪽의 조사정점에서는 암컷의 구성비가 크게 감소하고 어린 개체를 거의 발견할 수 없는 등 개체군이 임포섹스의 영향을 받고 있음을 알 수 있었다. 두 종의 체내에 함유된 트리부틸주석(TBT)과 트리페닐주석(TPT)의 농도를 분석한 결과 각각 0.18-1.45 $\mu\textrm{g}$/g, 0.42-6.30 $\mu\textrm{g}$/g의 범위에 있었으며, 임포섹스의 정도는 트리부틸주석과 트리페닐주석의 체내 농도와 밀접한 관계를 보였다. s 대수리와 뿔두드럭고등의 임포섹스는 우리 나라에서 유기주석 화합물의 오염을 나타내는 좋은 지표로 사용될 수 있으며, TBT의 사용 규제이후 그 효과를 감시하기 위한 용도로도 유용하게 사용될 수 있다.

• Smart Structures and Systems
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• v.16 no.4
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• pp.743-758
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• 2015

This paper presents an advanced life cycle cost (LCC) analysis of a ground source heat pump (GSHP) system and suggests a smart operation mode with a thermal performance test (TPT) and an energy pile system constructed on the site of the Incheon International Airport (IIA). First, an economic analysis of the GSHP system was conducted for the second passenger terminal of the IIA considering actual influencing factors such as government support and the residual value of the equipment. The analysis results showed that the economic efficiency of the GSHP system could be increased owing to several influential factors. Second, a multiple regression analysis was conducted using different independent variables in order to analyze the influence indices with regard to the LCC results. Every independent index, in this case the initial construction cost, lifespan of the equipment, discount rate and the amount of price inflation can affect the LCC results. Third, a GSHP system using an energy pile was installed on the site of the construction laboratory institute of the IIA. TPTs of W-shape and spiral-coil-type GHEs were conducted in continuous and intermittent operation modes, respectively, prior to system operation of the energy pile. A cooling GSHP system in the energy pile was operated in both the continuous and intermittent modes, and the LCC was calculated. Furthermore, the smart operation mode and LCC were analyzed considering the application of a thermal storage tank.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.10 no.2
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• pp.1-6
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• 2012

Purpose : This study is to investigate the modulatory effects to the ultraviolet induced erythema of pain processing system. Methods : Thirty six healthy volunteers were divided into none treatment group (n=6), indomethacine group (n=6), subsensory level electrical stimulation group (n=6), sensory level electrical stimulation group (n=6), motor level electrical stimulation group (n=6), noxious level electrical stimulation group (n=6). Subjects were induced erythema for three times minimal erythema dose (MED) at upper arm of dermatome C6 level. Each experimental group had mechanical pain threshold (MPT), electrical pain threshold (EPT), thermal pain threshold (TPT). Results : This study revealed that we observed that pain thresholds were significantly correlated with each other in pain processing system. The effect of electrical stimulation levels evaluates were shown to be significant differences pain control effect in electrical stimulation group (sensory, motor level electrical stimulation groups) more than indomethacine group, subsensory level and control group. Conclusion : In this study, it was found that the effect of ultraviolet induced erythema of pain control by modulatory electrical stimulation.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.1
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• pp.14-19
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• 2014

This paper presents a preliminary experimental and computational study on the evaluation of thermal performance and initial cost of U, W and coil type ground heat exchangers (GHEs). Heat exchange rate of the individual GHE was evaluated from the thermal resperformance test (TPT) results, and the construction cost was also calculated. For more information, GLD (ground loop design) simulations of various piping size are carried out. From simulation results, the optimized GHE was suggested based on the thermal performance and construction cost as well. Besides, the required borehole length of U and W type GHEs was calculated considering a real construction condition using GLD program.