化學技術情報에 대한 定期刊行物의 素引作業에 關한 硏究

鄭炅樂 全北大學校 1976 論文集 Vol.18 No.-

The uniterm card system and the termatrex card system, both based on the principle of coordinats indexing, have been analyed as specified below, along with the analysis of thesaurus as a term control descriptor. (1) The uniterm card system: merits: a. easy to use even without technical knowledge. b. inexpensive c. possible to store much information with few cards. d. mechanizable by the method of concept coordination. e. convenient as a means of storing and retrieving documents concerning single subjects. demerits: a. its user should have sufficient knowledge about the subject matters concerned to arrange various relations among uniterms and to modify word order and meanings. b. the system is complex and requires time and efforts in analyzing subject matter. c. it is difficult to store much information in smallsized cards. d. the retrieval process in complicated. (2) The termatrex card system: merits: a. the retrieval process is simple. b. information can be retrieved with little expense. c. it is easy to use. d. information retrieval takes little time. e. it is possible to select or add any indexing terms. demerits: a. the amount of information storage is limited to 100,000 items, due to the design of cards. b. The installation of input machines costs much. c. Input processes require much efforts. d. Materials cannot be retrieved directly: only their code numbers are retrieved. e. it is difficult to revise information file. f. the functions of storage and retrieval are not interrelated. (3) These systems are applicable to: a. retrieval of pattern information. b. management of research reports. c. management of (architectrual) desingns. d. management of medical research material. e. personnel management. f. management of properties and lands. g. management of information on chemical products. h. development of ready-made articles. (4) In thesaurus, the meaning, hierarchy, and connotation of terms are well specified and controlled, so the thesaurus can be valuable for the classification, storage, retrieval, and distribution of information. On the other hand, the descrpitor should be used only by those who sufficiently know how to use it, because it is too restricted to accommodate natural language. Since the uniterm card system and termatrex card system are simple, inexpensive, and practical methods of information storage and retrieval, they can be usefully adopted as means of pre-computer analysis of technical and scientific information.

陽이온交換樹脂의 分理性能에 關한 硏究

鄭炅樂 全北大學校 1973 論文集 Vol.15 No.-

The quantitative separation of five metals-Sodium, Karium, Lithium, Calcium, Aluminium by Amberlite IR-120 resin has been described as the following: 1. Mixing the same amount of O.IN HCI as sample metals solution, Amberlite IR-120 resin has the highest adsorption capacity for Sodium and Karium. 2. In neutral solution, Amberlite IR-120 resin has the highest adsorption capacity for Lithium. 3. When each Calcium, Aluminium sample solution has PH=2.0, PH=2.5, Amberlite IR-120 resin has the highest adsorption capacity for Calcium and Aluminium. 4. Amberlite IR-120 resin has the highest adsorption capacity for Calcium among five metals. Therefor Calcium should be adsorped selectively by Amberlite IR-120 resin.

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.

乾式遠心力 集塵裝置에 關한 硏究

鄭炅樂 全北大學校 1982 論文集 Vol.24 No.-

The performances of Micro-cyclone and Multi-microcyclone were examined with various experimental conditions-changing the inlet velocities for their collection efficiency and pressure drop and the inclined angles of Micro-cyclone, such as 0˚, 30˚, 60˚, 75˚, 80˚ and 90˚. The following results were obtained. (1) Micro-cyclone and Muti-microcyclone were so called the air centrifugal type dust collector. (2) The limited particle size of collection of Micro-cyclone and Multi-microcyclone was about 1㎛ and their collection efficiency was above 98 percentage. (3) Micro-cyclone and Multi-microcyclone were simple and have not a movable part. Therefore they have no trouble. (4) The influence of collection efficiency on the inclined angle of Micro-cyclone was not significant. For 90˚ inclined angle of Micro-cyclone, its collection efficiency decreased about 2.3 percentage. (5) For the inlet velocities from 15m/s to 20m/s, Micro-cyclone had the pressure drops from 75mn H_2O to 140mmH_2O. (6) Because the other substances could not be added in collection particles, they also could be used for the recovery apparatus.

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/㎥.

Table Feeder의 連續定量 供給 (Ⅰ)

鄭炅樂,崔東珪,金起柱 全北大學校 1979 論文集 Vol.21 No.-

A Continuous Uniform Feeding method is studied with a modified table feeder. The table feeder examined has either two or three scrapers. Powders used in the experiment are quartz sand, talc and calcium carbonate covering a wide range of flowability. With respect to testing methods of a feeder, the effect of sampling period on the precision is studied both experimentally and thearetically. As a result, variation of precision with sampling period becomes clear even when the powder flow rate has a periodic fluctuation.

Table Feeder의 連續定量供給에 關하여 (Ⅱ)

崔東珪,鄭炅樂,金起柱 全北大學校 1980 論文集 Vol.22 No.-

A Continuous Uniform Feeding method is studied with a modified table feeder. The table feeder examined has either two or three scrapers. Powders used in the experiment are talc, calcium carbonate, and quartzsand covering a wide range of flow ability. Precision of feeding is tested with particular attention to characteristics of the feeder and properties of powders discharged. Furthermore, with respect to testing methods of feeder, the effect of characteristics of the feeder and properties of powders discharged on the precision is studied both experimentally and theoretically. As a result, variation of precision with characteristics of the feeder and properties of powders discharged becomes clear even when the powder flow rate has a periodic fluctuation.

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.

內燃機關用 사이클론形 空氣淸淨器의 開發에 關한 硏究 : 第1報 小型 自動車用 內燃機關에 對하여 1st Report, For Internal Combustion Engine as Applied to Small-size Motorcar

崔東珪,鄭炅樂,金起柱 全北大學校 1979 論文集 Vol.21 No.-

The dust collection efficiency and pressure loss of a cyclone type air cleaner (Multi microcyclone described in this report) as applied to a four-cylinder four-stroke internal combustion engine and the effect of this aircleaner on the volumetric efficiency of the engine were researched in a series of engine motoring tests. The test results were compared with those obtained in a series of tests by using a blower. The performances of a paper filter were also tested by the same methods. The experimental results are summarized as follows; In the engine test, the dust collection efficiency of the multi microcyclone was about 98% at 3,500 r.p.m. and about 96% at 700 r.p.m. The efficiency of the paper filter was 98~99% at low speed but decreased to 86% at 3,500.r.p.m of engine. The multi micro-cyclone had a little air flow resistance. The test engine with the above cyclone showed rather a higher volumetric efficiency by about 8% than one without any air cleaner at the engine speed of the maximum volumetric efficiency.

혈관 내 폐보조장치에서의 압력손실 예측

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

The purpose of this study was making a equation to predict relationship between pressure drop and frontal area in 40% glycerol solution at 37 ℃. Before using whole blood, we estimated pressure drop with experimental equation, and compared the results with experimental results. Also, we tried to make module design that contained the maximum number of hollow fiber membranes in 3㎝diameter tube. We have observed pressure drop of 40% glycerol solution flow rate in each modules that have been changed by the number of the hollow fibers, and studied about the equation related between flow rate and pressure drop, friction factor and Reynolds number. The results showed that the pressure drop which was calculated with the various frontal area was similar to the pressure drop of using the equation obtained from the experimental. Also, the maximum number of hollow fiber is 675, which can be inserted in 3㎝diameter tube when the out side of diameter was 380㎛. It satisfied pressure drop(<15㎜Hg).