섬유상활성탄에 의한 수용액중 페놀류의 흡착특성

정경락,장경환 全北大學校 1992 論文集 Vol.34 No.-

The adsorption characteristics of phenols by the surface-modified activated carbon fibers from its aqueous solution was examined. Cellulose activated carbon fiber(toyobo Co. KF-1500) was used as an adsorbent, and it was treated with heat, air and helium. Pore-size distribution, BET surface area and surfce acidity were measured. The adsorption isotherms were found to conform with the Freundlich equation and its k values were ranged from 1.5381 to 3.6076 mmol/ g and its 1/ n values were ranged from 0.1798 to 0.3144. The affinity of each adsorbate on activated carbon fiber increased in the order ; Phenol <PCP<PNP. The adsorption capacity decreased when oxidized carbon was used, while it increased when redused carbon was used. The adsorption capacity increased when its surface area increased. It is concluded that the adsorption capacity changes in relation with the surface oxides and the surface area of the activated carbon fiber.

우리나라 산업의 정밀측정기술 수준분석

안웅환,남경희,안병덕,박병선 한국생산성학회 2003 生産性論集 Vol.17 No.3

The precision measurement technology is the infrastructure of industry technology and thus it is the critical element in the quality and hi-tech products. Nevertheless, the precision measurement technology in Korean industry is the lower level of the advanced state. In this study, we survey the demand of precision measurement technology including instrument and technologies in Korean industry, and provide the objective data on the level of precision measurement technology based on the report "A Study on the Current Status of Precision Measurement in Korea(KRISS, 2001)" . We summarize contents on the precision measurement technology in Korean industry, provide the assessment model for the level of precision measurement technology, and analyze the results of these. The level of the precision measurement technology of National Standards Institution, MISS, approaches those of the advanced state, but levels of the precision measurement technology in Korean industry are 2-3 years behind levels of National Standards Institution. Analysis model and results are analyzed for the important index to compare the levels of the precision measurement technology in Korean industry. Therefore, it is expected to provide the development for precision measurement technology and improve the system of precision measuring instruments, level of precision and accuracy, calibration, technical manpower for measurement etc. in Korean industry.

아동기 스포츠경험이 여가 태도에 미치는 영향

손경환 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.6

Though the prediction that sports activity participation in childhood is likely to contribute to a positive leisure attitude is a possible truth, it has not been studied yet, so the necessity of this study is worth enough. On the basis of this recognition, this study was aimed to identify how the experience in childhood's sports participation affects adulthood's leisure attitude. The subjects of this study were D university students with experience in childhood's sports activities as of November, in 2003 and 700 samples were extracted using cluster random sampling. Among them 106 with improper response were excluded and finally 594 were used for data analysis. Structured questionnaires were used. The statistical methods utilized in this study for analyzing the collected data were frequencies analysis, ANOVA, correlation, and multiple regression. The findings were as follows: First, sports activity experience in childhood had an effect on an adulthood leisure attitude. Second, sports activity experience in childhood had an effect on an adulthood leisure attitude(acknowledgement). Third, sports activity experience in childhood had an effect on an adulthood leisure attitude(behavior).

건식 미분 분급장치의 특성에 관한 연구

장경환,김성종,정경락 全北大學校 1990 論文集 Vol.32 No.-

A new air classifier with cut size smaller than about 10㎛, which allowed rapid classification to avoid the disturbance of particles reagglomeration, was designed and manufactured. The characteristics of the air classifier for fine powders was experimentally investigated. The results of the experimentation could be summerized as follows. 1) As the velocity of laden air was increased, the entrainment of fine particles into the coarse side was impressed.. 2) When the velocity of clean air was equal to the velocity of laden air, the sharpness index was good. 3) By sucking a portion of clean air into the fine side, the entraintment of fine particles into the coarse side was effectively suppressed. 4) The cut size and the classification performance were not affected by feed concentration up to at least 0.3kg/㎥.

안료 혼합비가 도고액과 도공지 물성에 미치는 영향

김경동,박종열,김철환 경상대학교 농업생명과학연구원 2002 농업생명과학연구 Vol.36 No.2

본 연구는 도공액 설계에 있어서 안료의 종류를 달리한 도공액에서 클레이와 중질탄산칼슘의 혼합비가 도공액 및 도공지 물성에 미치는 영향을 분석하였다. 안료입자의 비표면적이 클수록 동일한 도공층 강도를 유지하기 위해서는 접착제 소요량이 많았으며 중질 탄산칼슘보다는 클레이가 접착제를 더 많이 요구되었다. 접착제의 혼합비율이 증가함에 따라 No.1 Clay의 고전단 점도는 증가한 반면 No.2 Clay는 감소하였고 GCC-95는 증가하는 경향이 있었지만 큰 변화를 보이지 않았다. 백지광택과 K&N 잉크 흡수성은 감소하는 경향을 나타내었으나 백색도는 아무런 변화를 보이지 않았다. Clay와 GCC-95가 혼합된 도공지의 물성은 중질 탄산칼슘 비율이 증가함에 따라 투기도, 백색도 와 K&N ink 흡수성은 증가한 반면 백지광택과 인쇄광택은 감소하였다. This study was carried out to investigate the effect of different kinds of coating pigments on the properties of coating colors and coated paper. The pigment with greater specific area consumed more binders in order to maintain the stable structure of a coated layer, and GCC required more binders than clay. While increased addition of coating binder with No.1 clay made a high shear viscosity raised, a high shear viscosity of No.2 clay was decreased and that of GCC-95 was rarely changed. Paper gloss and K&N ink receptivity were decreased and brightness was little changed. Brightness and K&N ink receptivity of paper coated with mixed coating color of clay and GCC-95 were improved but paper gloss and print gloss were decreased.

접착제 첨가량이 도공액과 도공지 물성에 미치는 영향

김경동,박종열,김철환 경상대학교 농업생명과학연구원 2002 농업생명과학연구 Vol.36 No.1

본 연구는 도공액 설계에 있어서 접착제가 도공액 및 도공지 물성에 미치는 영향과 3종류의 안료를 사용한 도공액에서 클레이와 중질 탄산칼슘의 혼합비가 도공액 및 도공지 물성에 미치는 영향을 분석하였으며 그 결과는 다음과 같다. 안료입자의 비표면적이 클수록 동일한 도공층 강도를 유지하기 위해서는 접착제 소요량이 많았으며 중질 탄산칼슘보다는 클레이가 접착제를 더 많이 필요로 하였다.접착제의 혼합비율이 증가함에 따라 No.1 Clay의 고전단 점도는 증가한 반면 No.2 Clay는 감소하였고 GCC-95는 증가하는 경향이나 큰 변화를 보이지 않았다. 백지광택과 K&N ink 흡수성은 감소하는 경향이나 백색도의 변화는 보이지 않았다. Clay와 GCC-95가 혼합된 도공지의 물성은 중질 탄산칼슘 비율이 증가함에 따라 투기도, 백색도와 K&N ink 흡수성은 증가한 반면 백지광택과 인쇄광택은 감소하였다. In this study, the effect of latex on coating colors and coated paper properties was investigated. Also the optimum dosage of latex for commercial coated paper was carried out using three kinds of pigment. The effect of the ratio of clay and ground calcium carbonate on coating colors and coated paper properties was studied with triangular coordinates. From the result, it can be said ; More latex was needed to get the good coating strength in case of higher specific surface area. And the clay required more latex than the ground calcium carbonate. The high shear viscosity was increased for No.1 clay when the amount of latex was increased, but it was decreased for No.2 clay. However, it was almost the same as ground calcium cafbonate. Paper gloss and K&N ink receptivity were decreased with the increase of latex content, but brightness showed no difference. Compared to control coating color(No.1 clay : No.2 clay : GCC-95 = 15 : 25 : 60), latex was needed 14.0, 13.0, and 10.5 pph for No.1 clay, No.2 clay and GCC-95, respectively, to keep the same pick strength with control. In the case of using clay and ground calcium carbonate, the porosity, brightness and K&L ink receptivity were increased, but paper gloss and print gloss were decreased with the increase of ground calcium carbonate. It can be said that the pigment ratios of 0-40% for No.1 clay, 10-50% for No2 clay and 50-60% for GCC-95 are needed to get properties of 85-86% for brightness, 73-76% for paper gloss and 90-91% print gloss. Estimated brightness, paper gloss and print gloss were similar to predicted values with triangular coordinates for control coating color(No.1 clay : No.2 clay : GCC-95 = 15 : 25 : 60).

수용액중에서 분산제가 초미립자의 분산과 응집에 미치는 영향

황성태,장경환,정경락 全北大學校 1996 論文集 Vol.42 No.-

The dispersibility of ultrafine particles is affected by the kinds and amount of dispersants. The optimum dispersive condition for ultrafine particles was determined from the measurement of the zeta-potential and particle size distribution at concentrations. The zeta-potential and the particle size distribution of dilute suspension was measured using the light scattering method. Also, the influence of kinds and amount of diapersants on the dispersion of TiO_2 fine particle in water is discussed by the DLVO theory. In particular it is shown that the optimum concentration of a dispersant obtained experimentally is approximately in accordance with the concentration of the dispersant showing the maximum total potential energy(V_Tmax) calculated from the DLVO theory which is coincident with the one showing the maximum zeta-potential.

혈관 내 폐 보조장치에서 적혈구의 microencapsulation에 의한 산소전달속도의 향상

박재관,김기범,정경락,장경환 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

In this study, we tried to improve oxygen transfer rate and reduce pressure drop on intravascular lung assist device with microencapsulation of red blood cells, because microcapsulation of red cells reduce blood hemolysis. Hemoglobin was purified from outdated human red blood cells used. Phospholipid was purified from egg yolk. The hemosome was prepared by encapsulation of hemoglobin with phospholipid multilayer, using rotary vacuum evaporator. The function of hemosome was tested by measuring oxygen dissociation curve using blood gas analyzer. Oxygen dissociation curve of hemosome showed the same figure as the curve of normal red blood cells. Pressure drop showed lower use of hemosome rather than normal blood, because viscosity of hemosome are lower than that of normal blood. Also, oxygen transfer rate showed lower use of hemosome rather than normal blood at 2 hour, but it showed higher use of hemosome rather than normal blood after 2 hour. Because microencapsulation of normal red blood cells prevent hemolysis of normal red blood cells.

하악골 절제술후 재이식된 돌결자가골 재이식 : 치험 3례

김 식,김수관,김운규,김수민,류종희,이준길,조경안,김수흥,정태영,여환호 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.2

We described three cases of immediate reimplantation of a frozen-thawed autogenous mandible composed of a mixture of iliac bone, marrow, and particulate hydroxyapatite in tumors of the mandible. Acceptable outcomes were obtained in three patients who underwent immediate autogenous mandibular graft reconstruction. The conditions leading to successful outcome of the procedure are also discussed. Reimplantation of frozen autogenous lesioned mandible was performed in three patients with mandibular tumors. Two reimplanted grafts survived without complications following surgery. One case had postoperative infection that resolved with appropriate antibiotic treatment. There were no recurrences of the primary lesions. Satisfactory facial contour after surgery was achieved. These results are most promising, and we believe that, with further refinement, this technique will offer a new and acceptable modality for facial reconstruction in patients with cancer.

Comparison of Anti-oxidant and Anti-inflammatory Effect of Herbal Extracts by Extraction solvent

Gyeong Hwan Lee,Yun Geun Kim,Keon Hee Ko,Hyeong-Hwan Lee,Seon Jeong Kim 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10