• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 추계학술대회
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• pp.175-177
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• 1994

The wear corrosion behaviour of a nitrogen ion implanted super stainless steel (S.S.S, 22Cr - 20Ni - 6Mo - 0.25N) was compared with those of S.S.S, 316L SS and TiN coated 316L SS. The Cr and Ni amounts won out from the materials were investigated using an electrothermal atomic absorption spectrometry. We observed that the Cr dissolution rate of the S.S.S was similar to that of 316L SS, however, the Ni release of the S.S.S was feater than 316L SS. The metal ions released from the nitrogen ion implanted S.S.S surface were significantly reduced. The wear corrosion behaviour of the stainless steels was not correlated with the results shown by a static metal ion release test.

• 한국운동역학회지
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• 제22권2호
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• pp.131-140
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• 2012

This study was to investigate the relationship between the distance and projection factors, angle factors of javelin in women's javelin throwing. The data were collected in the 2011 National Sports Festivals for 11 players. Three-Dimensional motion analysis using a system of 4 video cameras at a sampling frequency of 60 fields/s was performed for this study. The factors of release conditions calculated using Matlab 2009a program. The statical analysis on the records(n=42) included mean and standard deviation of the mean(SD), Pearson's product moment correlation coefficient(SPSS Version 16.0 for Windows). There was a statistically significant positive relationship between the records and release velocity(r=.866, p<.01), height(r=.433, p<.01) and height rate(r=.340, p<.05). The attitude angle, release angle, and attack angle showed not a statistically significant relationship between the records. The medial-lateral tilt angle of javelin showed not a statistically significant relationship between the records, but the yaw angle of javelin(r=.549, p<.01) showed a statistically significant positive relationship between the records.

• 폴리머
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• 제37권3호
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• pp.294-301
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• 2013

Polymersomes made of biodegradable triblock copolymers based on poly(fumaric acid-co-sebacoyl chloride)/PEG (PEG-co-P(FA/SC)-co-PEG) were prepared and studied in aqueous solutions. TEM confirmed the formation of vesicles in aqueous media. Aggregation behavior of the copolymers was studied by fluorescence spectroscopy of 8-anilino-1-naphthalenesulfonic acid, and the critical aggregation concentration (c.a.c.) of the copolymer was found to be ${\sim}26.2{\mu}M$ indicating desirable stability of the vesicles. Dynamic light scattering revealed that the size of the vesicles was distributed within the range of 170-270 nm. Turbidity measurements confirmed the relative short-term stability of the polymersomes. Carboxyfluorescein, a hydrophilic compound, was simply encapsulated in the vesicles during polymersome preparation. The release of encapsulant from the polymersomes at 25 and $37^{\circ}C$ lasted about 3 weeks, and the rate of release followed a first-order kinetics. The release is speculated to be primarily carried out through diffusion. These results confirm that these polymersomes are promising as controlled-release carriers of various drugs.

• Archives of Pharmacal Research
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• 제14권4호
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• pp.298-304
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• 1991

Isoprinosine, an antiviral agent with a bitter taste, has been clinically used up to a maximum of 4 g daily in 4-8 doses. In this investigation, isoprinosine was microencapsulated with ethylcellulose 22 cps, 50 cps and 100 cps by means of polymer deposition from cyclohexane through temperature change. Complete removal of cyclohexane from the microcapsules was necessary, since ethylcellulose-coated microcapsules obtained from cyclohexane medium were heavily solvated with cyclohexane and formed lumps even after drying. The displacement of cyclohexane by n-hexane during isolation of microcapsules (Method III) or the freezing of the anal-washed microcapsules before drying (Mothod II) provided the dried products which were more discrete microcapsules than those which were simply dried in the air overnight (Method I). Method III was especially the most effective procedure in preparing finer and more discrete microcapsules. The drug-release from microcapsules was influenced by the ratio of core to wall, the viscosity grade of ethylcellulose and the overall microcapsule size. The release rate was adequately fitted to both the first-order and the diffusion-controlled processes. It is therefore possible to design the release-controlled microcapsules with ethylcellulose of different viscosity along with various core to wall ratio.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1572-1582
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• 2003

Hybrid rocket combustion has a manifestation of stable response to the perturbations compared to solid propellant combustion. Recently, it has revealed that the low frequency combustion instability about 10 Hz was occurred mainly due to thermal inertia of solid fuel. In this paper, the combustion response function was theoretically derived by use of ZN (Zeldovich-Novozhilov) method. The result with HTPB/LOX combination showed a quite good agreement in response function with previous works and could predict the low frequency oscillations with a peak around 10 Hz which was observed experimentally. Also, it was found that the amplification region in the frequency domain is independent of the regression rate exponent n but showed the dependence of activation energy. Moreover, the response function has shown that the hybrid combustion system was stable due to negative heat release of solid fuel for vaporization, even though the addition of energetic ingredients such as AP and Al could lead to increase heat release at the fuel surface.

• 한국환경농학회지
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• 제26권3호
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• pp.228-232
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• 2007

고추작물의 생육기간 중 양분요구특성에 부합하는 새로운 완효성 복합비료를 개발하기 위해 질소 용출율이 110일과 150일로 조절된 완효성 복합비료 110T와 150T을 제조하여 포장 조건에서 질소용출특성을 조사하였다. 그리고 고추에 대한 관행시비량 기준으로 60%의 완효성 복합비료 110T, 150T와 40%의 속효성 비료를 혼합하여 제조한 원예용 완효성 복합비료 CF110과 CF150의 토양 내 질소 용출 특성과 고추의 생육 및 수량에 미치는 영향을 관행처리(NPK)와 비교하여 다음과 같은 결과를 얻었다. 밭 토양조건에서 완효성 질소비료 110T와 150T의 질소 용출율은 시용 8주경과 후 각각 63%, 53%가 용출되어 원예작물인 고추재배에 적용성이 높을 것으로 평가되었다. 원예용 복합비료 CF110과 CF150을 전량 기비로 시용하여 고추를 재배하였다. 고추의 전 생육기간 동안 토양 내 무기태 질소($NH_4^+-N$과 $NO_3^--N$) 함량은 원예용 완효성 복합비료 CF110 처리구에서 NPK 처리구에 비해 높았다. 그러나 CF150 처리구에서 토양 중 무기태 질소 함량은 정식 후 8주까지 NPK 처리구에 비해 낮았다. 원예용 완효성 복합비료 CF110 처리구와 NPK 처리구사이의 고추 생육과 무기성분 함량은 뚜렷한 차이가 없었지만, 수량은 CF110 처리구에서 NPK 처리구에 비해 4% 증수 되었다. 그러나 원예용 완효성 복합비료 CF150 처리구는 NPK 처리구에 비해 수확 후 엽중 질소함량이 낮았으며, 수량도 2% 감소되었다. 따라서 고추재배를 위한 적합한 완효성 복합비료는 CF150 보다는 CF110이었다.

• 유기물자원화
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• 제27권1호
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• pp.49-56
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• 2019

본 연구의 목적은 배추재배 시 바이오차 펠렛 완효성 비료의 적정 시용량 구명을 위해 수행하였다. 바이오차 팰릿 완효성 비료는 돈분과 바이오차 혼합비(6 : 4)로 조제한 후 N : P : K 용액을 추가하여 총 질소 함량이 약 9%가 되도록 조제하였다. 본 시험의 처리는 대조구, 추천 질소 시비량의 바이오차 펠렛 완효성 비료 질소기준 40%(N 40%), 바이오차 펠렛 완효성 비료 질소기준 40% + 0.07M MgO(N 40% + 0.07M MgO)와 바이오차 펠렛 완효성 비료 질소기준 60%(N 60%) 시용구로 구성되어있다. 배추의 생육기간동안 토양 중 $NH_4-N$, $NO_3-N$, $P_2O_5$, $K_2O$의 농도 변화를 분석하였다. 실험 결과로서 토양중의 $NH_4-N$, $NO_3-N$, $K_2O$ 함량은 대조구와 비교하여 N 40%처리구가 유의차를 보였다. 토양 중의 $P_2O_5$농도는 바이오차 팰릿 완효성 비료의 처리구들 중 N 40%가 가장 높았다. 배추의 생체중은 N 40% 처리구는 대조구와 비교하여 유의적인 차이가 나지 않았으며(p>0.05), N 40% + 0.07M MgO 처리구와 N 60% 처리구는 대조구에 비해 감소하였다. 농경지에서 배추재배 시 추천 질소 시비량 기준의 N 40%가 적정 시용량이라 판단된다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권2호
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• pp.147-154
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• 1998

It was attempted to clarify the participation of $K^+-channels$ in the post-receptor mechanisms of the muscarinic and $A_1-adenosine$ receptor- mediated control of acetylcholine (ACh) release in the present study. Slices from the rat hippocampus were equilibrated with $[^3H]$choline and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 V/cm, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium-outflow was investigated. Oxotremorine (Oxo, $0.1{\sim}10\;{\mu}M$), a muscarinic agonist, and $N^6-cyclopentyladenosine$ (CPA, $1{\sim}30\;{\mu}M$), a specific $A_1-adenosine$ agonist, decreased the ACh release in a dose-dependent manner, without affecting the basal rate of release. 4-aminopyridine (4AP), a specific A-type $K^+-channel$ blocker ($1{\sim}100\;{\mu}M$), increased the evoked ACh release in a dose-related fashion, and the basal rate of release is increased by 3 and $100\;{\mu}M$. Tetraethylammonium (TEA), a non-specific $K^+-channel$ blocker ($0.1{\sim}10\;{\mu}M$), increased the evoked ACh release in a dose-dependent manner without affecting the basal release. The effects of Oxo and CPA were not affected by $3\;{\mu}M$ 4AP co-treatment, but 10 mM TEA significantly inhibited the effects of Oxo and CPA. 4AP ($10\;{\mu}M$)- and TEA (10 mM)-induced increments of evoked ACh release were completely abolished in Ca^{2+}-free$ medium, but these were recoverd in low Ca^{2+}$ medium. And the effects of $K^+-channel$ blockers in low Ca^{2+}$ medium were inhibited by $Mg^{2+}$ (4 mM) and abolished by $0.3\;{\mu}M$ tetrodotoxin (TTX). These results suggest that the changes in TEA-sensitive potassium channel permeability and the consequent limitation of Ca^{2+}$ influx are partly involved in the presynaptic modulation of the evoked ACh-release by muscarinic and $A_1-adenosine$ receptors of the rat hippocampus.

• 한국토양비료학회지
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• 제20권2호
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• pp.97-100
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• 1987

비닐멀칭 재배용 복비(複肥)는 요소(尿素), DAP, 염화가리(鹽化加里)를 원료비료(原料肥料)로, 제오라이트, 부생석고(副生石膏) 및 분뇨잔사(糞尿殘渣)를 증량제(增量劑)로 하여 아미노산폐액(酸廢液)을 이용(利用) 조립(造粒) 제조(製造)하였다. 시제품(試製品)의 NPK성분함량(成分含量)은 고추비료(肥料), 12-10-11, 5, 참깨비료(肥料) 8-8-6, 땅콩비료(肥料) 4-19-14이었고 시제품(試製品)의 수중(水中)N용출량(溶出量)은 비교적(比較的) 낮아 고추비료(肥料)에서 80%, 참깨비료(肥料) 55%, 땅콩비료(肥料) 70%로 비료지효화(肥料遲效化) 기준치(基準値) 50%에 근사(近似)하여 비닐멀칭재배시(栽培時) 전량기비시용(全量基肥施用)이 가능(可能)할 것이다.

• 한국환경보건학회지
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• 제32권1호
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• pp.27-35
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• 2006

This study was carried out to investigate the removal of nitrogen and phosphorus in municipal sewage depending on existence of biological coated media in BCM reactor. The reactor with biological coated media is the process combining $A_2/O$ process. The removal efficiencies for $COD_{Mn},\; BOD_5,\;SS$, T-N and T-P were $78\%,\;90.5\%,\;92.3\%,\;61.9\%,\;60.2\%$, respectively. The specific nitrification rate$(mgNO_3-N/gMLSS{\cdot}d)$ of Contact aeration basin was 52.2 and the specific denitrification rate$(mgNO_3N/gMLSS{\cdot}d)$ in anoxic basin was 95.1. Also, phosphorus release$(mgPO_4-P/gMLSS{\cdot}d)$ in Anaerobic basin was 71.8 and Phosphorus uptake$(mgPO_4-P/gMLSS{\cdot}d)$ in contact aeration was 27.1.