고속방사에 의해 제조된 PEN 필라멘트의 특성 : 방사속도에 따른 영향 Effects of Take-up Velocities

지동선,손준식 단국대학교 2001 산업기술연구 Vol.2 No.-

Polyethylene 2,6-naphthalate(PEN) filament by high-speed melt spinning was prepared at the take-up velocities of 1∼7 ㎞/min. The changes of the structure and physical properties caused by various take-up velocities were studied by measuring density, birefringence, x-ray diffraction, DSC, and tensile behavior. The PEN filament at high take-up velocities were show very different structure formation and properties. The orientation, especially in crystalline phase, was developed with the increase of take-up velocity. The physical properties(i.e. density, crystallinity, birefringence melting temperature, heat of fusion, tensile strength, tensile modulus)of the PEN filaments were increased with increasing of take-up velocities. These increasing tendencies were markedly appeared at the take-up velocities of 4∼7 ㎞/min by conditions due to suddenly orientation of shin molecules. The existence of extended non-crystalline molecules in the PEN filaments was appeared at take-up velocity about 4∼7 ㎞/min. It was found that they formed crystal at take-up velocity 7 ㎞/min, and their crystal

반응표면분석에 의한 직물의 투습성 평가

智東宣 단국대학교 1992 論文集 Vol.26 No.-

One factor influencing the comfort of fabrics for clothing is their resistance to the passage of water vapor. In this evaluation on the water vapor permeability of woven fabrics by response surface analysis, the water vapor transfer resistance of woven fabrics is a dependent variable, and three parameters of fabrics(i.e. thickness, porosity, and open free area) are simultaneously independent variables. The second order regression model on the water vapor transfer resistance(R_F) can be fitted from the method of least squares by response surface analysis. And the estimated value of water vapor transfer resistance of worsted fabrics made of ring spun yarns was approximately 0.82cm at the stationary point.

편마비 환자의 정상측과 마비측의 비복근 운동점에서의 근육 두께 차이

김동건,도현경,김현동,황지선,정규영,정호중 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.1

Objective : To investigate any difference of muscle thickness in the motor points of the gastrocnemius between the paretic and non-paretic legs in hemiplegics. Method : Ultrasonography was used to assess in vivo the gastrocnemius muscle thickness at the motor points in the paretic and non-paretic legs of twenty-four patients with stroke. Results : Muscle thickness at the motor points were reduced in the paretic legs compared to the non-paretic legs (p<0.05). There was no correlation between muscle thickness and duration of hemiplegia, site of hemiplegia. However, it did not take regular pattern of the muscular atrophy in the paretic legs. Conclusion : The gastrocnemius muscle of the paretic leg had smaller thickness compared with the non-paretic leg. The present results indicate that paresis in hemiplegics may affect the accuracy of intramuscular injection of botulinum toxin A. Therefore, we recommend ultrasonography for visually controlled, anatomically precise injection of botulinum toxins.

황토를 이용한 모직물의 염색에 관한 연구

지동선,김현성 단국대학교 1999 산업기술연구 Vol.1 No.-

The optimum conditions of loess dyeing were investigated to improve the color fastness and antibacteria properties of wool fabric dyed with the loess at various conditions such as loess, H_2SO_4. Na_2SO_4, concentration, time and temperature. With the increase in concentrations of loess and H_2SO_4, the dyeing temperature, and the dyeing time, the K/S values of the samples increased. But with the increase in concentration of Na_2SO_4, used as a retarder, the K/S values of the samples decreased. It was found that the optimum conditions of loess dyeing in order to give the color fastness to dry cleaning were loess 3∼5 % o.w.f., H_2SO_4 2∼3 %(v/v), Na_2SO_4, 5 % o.w.f., dyeing temperature 90℃, and dyeing time over 35 minutes. The results of antibacteria tests suggested that the antibiosis of wool fabric dyed with the loess is better than that of the undyed.

실록실화 폴리프로필렌 섬유의 열적 거동 및 인장특성

지동선,윤철수 단국대학교 2001 산업기술연구 Vol.2 No.-

Siloxylated polypropylene fibers using two polymers of polypropylene and aluminosiloxane were prepared by melt blending. The effects of blending ratio on the thermal behaviors and tensile properties of siloxylated polypropylene fibers were study. The thermal behaviors, X-ray diffraction, and tensile properties of siloxylated polypropylene fibers were investigated be DSC, X-ray, and UTM analyses. It was found that the melting temperature of siloxylated polypropylene blend were not changes with increasing the aluminosiloxane contents. But heat of fusion of siloxylated polypropylene blend were decreased with aluminosiloxane contents. In addition, the peak intensity of siloxylated polypropylene blend in X-ray diffraction pattern was decreased with increasing the aluminosiloxane contents. After these blends were prepared as a fiber, ones tensile properties were measured. The tensile strength and the tensile modulus were decreased with increasing the contents of aluminosiloxane in the siloxylated polypropylene fibers. Also, the elongation at break was increased with increasing the contents of aluminosiloxane in the siloxylated polypropylene fibers. From these results, in case of introducing aluminosiloxane to polypropylene, the miscibility of polypropylene was improved.

열유도상분리법에 의한 미세다공성 폴리에틸렌 중공사막의 제조에 관한 연구

지동선,공용운 단국대학교 1999 산업기술연구 Vol.1 No.-

The solid-liquid phase separation of the high density polyethylene(HDPE) hollow fiber membrane prepared via thermally induced phase separation process was thermodynamically investigated. As the amount of liquid paraffin(LP) used as a diluent increased, the equilibrium melting temperature given Hoffman-Weeks plots decreased. The value of Flory-Huggins interaction parameter obtained from the melting point depression in the HDPE/LP blends was -0.43. The phase was not separated in the melt state since it had good miscibility. However, the solid-liquid phase separation occurred at lower temperatures. The temperatures of crystallization and phase separation decreased with increase in the cooling rate. As the amount of liquid paraffin and draft ratio increased, the flux of polyethylene hollow fiber membrane increased. It was found that the optimum blend ratio for microporous polyethylene hollow fiber membrane of HDPE/LP blends was determined to be 40/60. The flux of polyethylene glycol solution under the same applied pressure and time was less than that of pure water for HDPE/LP 40/60 and 50/50(wt%).

Steam Press에 의한 毛織物의 치수變化에 관한 연구

智東宣 단국대학교 대학원 1987 學術論叢 Vol.11 No.-

As the experimental results of a continuing and repeating steam press by closing and opening press method in woven wool fabrics of Tropical, Twill, Gabardine, and Doeskin, the conclusions were as follows : In sewing process, after we took into consideration enough to the essence of press and the properties of materials, we justified in selecting of sewing machine, needle, hook, bobbin, sewing thread, the other accessaries, and so on. Especially in woven wool fabrics, it is desirable for us to begin sewing after we obtained previously a necessary information from weaving compaines and examined it thoroughly.

초등학생의 성별 및 인지양식에 따른 협동학습에서 나타나는 생물 관찰 특성

김지혜,김동렬,김선숙,문두호 부산대학교 사범대학 과학교육연구소 2006 科學敎育硏究報 Vol.33 No.-

This study examined the effects of the gender and the cognitive style which contribute to cooperative learning of elementaiy school children's competence in the observation of living things. The purpose of this study was to provide a basis for the effident teaching and learning in cooperative learning of elementary school children through careful analyses of children's observation. Results showed characteristic patterns of cooperative observation according to the gender and the cognitive style of children. The findings indicated that the field-independent groups reported more kinds observation than the field-dependent groups. The findings indicated that the girl's groups reported more kinds observation than the boy's groups except on animals. The effects of the gender on the observation of animals was not significantly different. Results of the analysis on the degree of focused observation showed that the field-independent groups reported more the degree of focused observation than the field-dependent groups and the girl's groups reported more the degree of focused observation than the boy's groups. As a result, the cognitive style and the gender could be one of the factor involved in the observation oh living things, therefore the further research of teaching methods and learning strategies should be encouraged in relation to this factor.

지하수 중 자연방사성물질의 위해성 관리에 대한 고찰

신동천,김예신,문지영,박화성,김진용,박선구 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.4

At present, the health risks associated with the natural radionuclides of ground water have become a concern as potential social problems. However, there are no regulatory actions or control strategies for such risks. Therefore, we have investigated and discussed the risks and associated management strategies for radionuclides in other countries. US EPA has proposed MCL (300 pCi/L) and AMCL (4,000 pCi/L) for radon, and 30 ppb for uranium, 15 pCi/L for gross-alpha and 5 pCi/L for radium as final MCLs. Also, Canada, WHO and European countries have their inherent management levels. Finally, we suggested several criteria for setting guidelines in our countries including exposure related criteria such as geological distribution, occurrence, exposure probability distribution, exposure population and multimedia exposure assessment, acceptable risk, and cost-benefit analysis. The national-scale exposure and risk assessment, and economic analysis should be conducted for producing and aggregating the representative information on these criteria.

알부민이 첨가된 시험관내 약역학 감염모델을 이용한 폐렴알균 치료에서 Ceftriaxone 일일 1회 요법

허지안,전혜선,박선희,최수미,김시현,이동건,최정현,유진홍,신완식 대한감염학회 2006 감염과 화학요법 Vol.38 No.6

배경 : Penicillin 내성 폐렴알균이 증가하는 지역에서 대안 중의 하나로 사용되는 ceftriaxone (CTR)의 적절한 용법, 용량을 파악하는 것이 중요하다. 본 연구는 임상에서 분리된 폐렴알균을 대상으로 시험관내 약역학 감염모델을 이용하여 알부민이 첨가된 경우와 첨가되지 않은 경우 CTR의 일일 1회 요법의 효과를 비교해 보고자 하였다. 재료 및 방법 : Penicillin 감수성(SM24), 중간내성(SM47), 내성(SM60)주를 대상으로 2-구획 시험관내 약역학 감염모델을 적용하였다. CTR 주입은 2 g씩 24시간마다로 사람의 약동학을 모의하였다. 알부민은 모델에서 4g/ dL가 유지되도록 하였다. 살균효과는 0, 2, 4, 6, 24, 30, 48시간째 집락수 변화로 측정하였다. 결과 : 모든 균주에서 알부민이 첨가되지 않은 경우 6시간 이내에 살균력이 관찰되었다. 최저억제농도 및 알부민 첨가유무에 관계없이 3주 모두 24시간째 살균력이 관찰되었고, 48시간째는 모두 측정한계 이하의 집락수로 감소하였다. 전 실험과정에서 CTR에 대한 내성주는 출현하지 않았다. 결론 : CTR의 일일 1회 요법은 알부민이 첨가되었을 때, 감수성, 중간내성, 내성주 모두에서 살균력 발현이 지연되었으나 최종효과는 알부민이 없을 때와 다르지 않았다. 앞으로 알부민 결합효과와 관련된 기초적인 추가 연구가 필요할 것으로 생각된다. Background : During the era of increasing penicillin resistant Streptococcus pneumoniae, it is important to have knowledge about adequate dosage and dosing interval of ceftriaxone (CTR). We examined efficacies of once-daily CTR and compared results in an in vitro pharmacodynamic infection model (IVPDIM) supplemented with albumin and those without albumin. Methods : Using three clinically isolated S. pneumoniae that were susceptible (SM24), intermediate (SM47) and resistant (SM60) against CTR, we utilized a two-compartment IVPDIM. CTR 2 g was administered intravenously every 24 h. Human albumin was added with concentration of 4 g/dL. Samples were removed at multiple time points over a 48-h period to determine the colony counts. Results : In SM24 and SM60, bactericidal effects were observed within 6 hours in groups without albumin. The number of colonies during 1st 6 hours were more decreased in albumin-free groups than in albumin-supplemented groups (P<0.05). In SM47, similar results were found during 1st 6 hours (P=0.03). But, regrowth was observed in albumin supplemented group at 30 h. Irrespective of results of minimal inhibitory concentrations and albumin supplementation, bactericidal effects were shown at 24 h in all 3 strains. All groups were decreased below the detection limit at 48 h. Development of resistance was not detected throughout the entire study period in either strain. Conclusions : Although extents of killing in albumin supplemented broth of once-daily CTR dosing were delayed in all 3 strains compared with those of albumin free broth, final efficacies were not different between the two groups.