• Title/Summary/Keyword: 1GR

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A Study on Immoblization of Pepsin (��프신의 고정화(固定化)에 관한 연구(硏究))

  • Park, Jong Lae
    • Current Research on Agriculture and Life Sciences
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    • v.3
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    • pp.166-173
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    • 1985
  • Several enzyme immobilization methods has been compared for immobilization of pepsin. Carboxymethyl cellulose and diethylaminoethyl cellulose were activated with Hcl and with NaOH, and were used for immobilization of pepsin. Sepharose-4B was activated cyanogen bromide, and was used for immobilization of pepsin. Porous glass beads were derivatized with 3-aminopropyitrlethoxysilane and with succinicanhydride, and were used for immobilization of pepsin. The results abtained were summarized as follow, 1. 10 mg/gr. dry bead and 15mg/gr. dry bead of pepsin were absorbed to CM-cellulose and DEAE-cellulose, 20 mg/gr. dry bead and 27 mg/gr. dry bead were coupled to CM-cellulose and DEAE-cellulose with glutaraldehyde respectively. Enzyme yields were 22% and 24% of soluble pepsin. 2. 16 mg/gr. dry bead of pepsin was attached to cyanogen bromide activated sepharose-4B, 19mg/gr. dry bead was cross linked to the activated bead with glutaraldehyde. Immobilized enzyme activity was 23% of soluble pepsin. 3. 40 mg/gr. dry bead of pepsin was conjugated to the derivatized glass beads. Immobilized enzyme activity was 45% of soluble pepsin.

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Development of welding process to rootpass for U-Groove without gap in pipe 1GR butt welding (파이프 1G 회전 맞대기 용접에서 갭 없는 U-그루브의 루트패스 용접공정 개발)

  • Son, Chang-Hui;Kim, Nam-Gyu;Cho, Sang-Myeong
    • Proceedings of the KWS Conference
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    • pp.40-40
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    • 2010
  • 산업현장에서는 파이프 또는 탱크류의 1GR용접에서 안정적인 이면비드를 가지는 루트패스 용접을 위해 2~3mm의 루트갭을 띄우고 용접봉 또는 필러와이어를 사용하는 TIG용접을 주로 한다. TIG용접은 고품질의 이면비드가 얻어지며, 용접인자의 제어가 쉽다는 장점이 있어 루트패스 용접에 많이 사용되고 있지만, 루트갭을 띄우면 이면비드는 잘 얻어지지만 용착금속량이 많아지게 되어 제작원가가 상승되고, 또한 소모성 와이어를 사용하는 GMAW에 비해 생산성이 낮다. 따라서, 안정적인 이면비드를 가지면서 생산성이 높은 1GR GMAW 루트패스 용접공정의 개발이 요구되지만, 이 경우도 루트갭이 2~3mm로 정해져 있으면 Fit-up공정에서 공수가 많이 필요하므로 근본적으로 루트갭이 없는 그루브에 대한 루트패스 용접이 더 바람직하다. 본 연구에서는 루트면 2.7mm를 가지는 U-그루브의 갭 없는 루트패스 용접에서 안정적인 이면비드가 형성되는 조건을 검토하기 위해 2.7t의 평판에 대하여 경사상진 각을 주고 기초 실험 후, U-그루브 맞대기 용접 실험을 진행하였다. 이 때, 경사상진 각은 용융금속이 중력으로 인해 아크 후방으로 밀리게 되고, 그로 인해 아크가 모재에 직접 닿게 되어 용입이 더 깊게되므로, 이면비드의 형성에 더 유리하다. 두께 2.7t의 연강 시편 2개를 갭 없는 I-그루브 맞대기 이음에서 Ǿ1.2 연강 솔리드 와이어를 사용하여 GMAW용접을 실시하였고, 용접전류, 용접속도, 경사상진 각, 위빙 폭, 위빙 주파수를 변경하여 각 조건에 대한 이면비드를 관찰하였다. 그 결과 경사상진 각 $25^{\circ}$, 전류 200A, 위빙폭 3mm, 위빙주파수 3Hz의 조건에서 안정적인 이면비드를 얻을 수 있었다. 또한, 현장에서 Fit-up중 발생할 수 있는 루트갭의 문제에 대하여 루트갭 1.2mm의 I-그루브 맞대기 용접에서 경사상진 각, 위빙 폭, 위빙 주파수는 갭 없이 실시한 실험에서 얻어진 가장 안정적인 결과를 사용하였고, 용접 전류, 용접 속도를 변경하여 이면비드를 관찰하였다, 그 결과 갭이 없을 때보다 약 80A 낮은 전류 조건인 120A에서 안정적인 이면비드를 얻을 수 있었다. 앞선 실험들을 기초로 하여 U-그루브 맞대기 용접을 실시 하였고, I-그루브 맞대기 용접에서 사용한 조건들과 유사한 용접 전류, 용접 속도에서 안정적인 이면비드를 얻을 수 있었다.

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Recovery of Copper from Spent Copper Solution of Printed Circuit Board Process by Solvent Extraction Method (인쇄회로기판 제조과정에서 발생되는 동폐액의 용매추출에 의한 재활용)

  • Moon, Young-Hwan
    • Clean Technology
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    • v.2 no.1
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    • pp.47-52
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    • 1996
  • The solvent extraction method was applied on a spent solution containing copper, which was produced in a printed circuit board process, to recover copper and to reuse the etching solution. Lix 64 N ($\alpha$-Hydroxyoxime + $\beta$-Hydroxybenzophenone Oxime) was used as a solvent. The acidic spent copper solution was mixed with and alkaline copper solution to pH=2. The solvent including 30 volume% of Lix 64 N extracted 17.1gr/l of copper from the mixed spent copper solution. In the continuous bench scale experiment, 4 stages for extraction, 2 stages for stripping and 4 stages for washing were used. Recovered copper was recycled as copper sulfate and the raffinate was reused as copper etchant. The percentage of copper recovery and the purity of copper sulfate were higher than 99.9%, respectively.

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A Study on the Chemical Characteristics of High and Low Productive Paddy Soil (고수확답(高收穫畓)과 저수확답(低收穫畓) 토양(土壤)의 화학적(化學的) 성질(性質) 비교(比較))

  • Oh, W.K.;Park, Y.S.;Chung, D.H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.1 no.1
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    • pp.7-11
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    • 1968
  • A high and low productive paddy soils were waterlogged at $30{\pm}2^{\circ}C$ for 35 days in the laboratory. The relation of pH and Eh changes, ferrous iron and ammonium nitrogen of these soils was studied. The results obtained are summarized as follows: 1. pH value has been increased for 13 days of incubation and after 13 th day, they maintain their pH value without marked change, and pH value of high productive soil is higher than that of low productive soil by 0.25-0.30. 2. Eh value has been decreased for 10 days of incubation and then they also maintain their Eh value without marked change. Eh value of high productive soil is lower than that of low productive soil by 50-70 mv. 3. In both soils ferrous iron formed under submerged condition increased steeply within 4-5 days of incubation and after that they maintain their content without marked change. The $Fe^{+{+}}$ content of high productive soil is higher than low productive soil by 1.0 mg/1 gr soil. 4. $NH_4{^{-N}}$ formed under submerged condition rapidly increased in the early period of incubation and after that decreased to a certain level and maintain their content, but its content of high productive soil is higher than that of low productive soil by $20-25{\gamma}/1\;gr$ at the early stage and lower at the latter period by $10-15{\gamma}/1\;gr$.

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A Study on the Underground Movement of Radionuclides(I) (방사성핵종의 지하이동 연구)

  • Hun Hwee Park;Kyong Won Han;Nak June Sung;Chul Soo Kim
    • Nuclear Engineering and Technology
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    • v.16 no.2
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    • pp.64-69
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    • 1984
  • With regard to the radioactive waste disposal, adsorption properties and migration rates have been evaluated for Cs-137 and Sr-90 with the domestic clay sampled from Cnyang, Sanchong and Mooan. Sorption coefficients (Ksorp) were determined by batch experiments. The measured values of Ksorp were ranged from 8000 to 17,000 ml/gr for Cs-137 of 0.1$\mu$Ci/ml, and from 10,000 to 15,000m1/gr for Sr-90 of 0.l$\mu$Ci/ml. Remarkably, Mooan clay showed lower values of Ksorp than those of the others. This could be explained by the poor soprtion capacity of the quartz found only in the Mooan clay. For the quantitative analysis, sorption isotherm equations of Freundlich type were made with the obtained values of Ksorp. $C_{R}$=18.0 $C_{A}$$^{0.74}$ : Cs-137, $C_{R}$=0.84 $C_{A}$$^{0.45}$ : Sr-90. By introducing the BOX model combined with the above relationships, simulation of underground nuclide movement was carried out. The results showed that the domestic clays could be the effective backfill material for repositories.itories.ies.

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Study of UV-cut Effect by Luminance and Size of pupil in lens (Luminance와 동공크기 변화에 따른 렌즈에서 UV 차단효과 연구)

  • Kim, Yong-Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.2
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    • pp.17-21
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    • 2001
  • We analyzed the luminance in the visual light region and the size of pupil by the luminance to estimate an UV-A line cut efficiency in the lens. The size of pupil by the luminance(L) was given by ${\Phi}=d-e{\cdot}tanh(f{\cdot}logL)$ and the transmittance efficiency value of a size of pupil was given by $T_r(r)=1-gr^2+hr^4$. We derived the absolute cut efficiency value ${\alpha}$ and the exclusion index $b=(1-{\alpha}){\times}100%$ about the UV-A in the $320{\sim}400nm$ regions. The ${\alpha}$ and b values were obtained respectively 0.018, 0.31, 0.273, 0.153 and 98, 69, 72, 85% of Uv-cut Lens, CR-39, red color and blue color.

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Mixed convection heat transfer from vertically parallel and misaligned plates (수직 평판의 평행배열과 엇갈린 배열에서 혼합대류 열전달)

  • 김상영;정한식;권순석
    • Journal of the korean Society of Automotive Engineers
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    • v.15 no.3
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    • pp.68-74
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    • 1993
  • The mixed convection heat transfer has been studied numerically for misaligned and parrallel arrays of two flat plates at 100.leg.Re.leg.700, 0.1.leg.B.leg.1.0, 0.2.leg.leg.PHI.$_{R}$.leg.1Gr=10$^{4}$ and Pr=0.71. For misaligned plates and parallel plates, the optimum plate spacings move to the narrow spacing as Reynolds number and .PHI.$_{R}$ increase and can be expressed by the correlation equations at Gr=10$^{4}$. The optimum plate spacings for parallel plates sharply move to the narrow spacing compared with misaligned plates. The maximum mean Nusselt number of parallel plates shows higher value than that of misaligned plates and can be expressed by the correlation equations at Gr=10$^{4}$.EX>.

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옥외 LED 조명을 위한 넓은 출력 전력 범위을 갖는 인터리빙 방식의 단일 전력 Flyback AC-DC Converter

  • Mun, Sang-Cheol;Gu, Gwan-Bon;Mun, Geon-U
    • Proceedings of the KIPE Conference
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    • pp.191-192
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    • 2012
  • 옥외 LED 조명은 수 많은 응용 분야가 있고, 출력 전력 크기에 따라 전력단이 single-stage 와 two-stage 구조로 나뉜다. Single-stage 구조는 낮은 전력 LED 조명에 적합하지만, 60~70W 이상에서는 효율이 떨어지고 변압기의 크기가 커져서 적용하기가 힘들다. 반면에 two-stage 구조는 보통 큰 전력이 필요한 응용분야에 사용되지만, 낮은 부하에서 낮은 역율을 나타내므로 넓은 출력전력 범위를 갖는 분야에 사용되기 어렵다. 이 문제를 해결하기 위하여 본 논문은 pulse duty cycle, pulse frequency modulation 제어 방법을 갖는 interleaved single-stage flyback AC-DC converter 를 제안한다. 제안된 컨버터는 입력 전압이 낮고 부하가 큰 경우 높은 효율을 보이고, 입력 전압이 높고 부하가 아주 작은 경우에도 높은 역율과 낮은 전류 왜곡을 보인다. 그 결과 하나의 AC-DC 컨버터를 넓은 출력전력 범위를 갖는 LED 조명분야 적용시킬 수 있다. 제안된 컨버터의 타당성을 검증하기 위하여 81W prototype을 가지고 실험하였다.

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가미귀용탕(加味歸茸湯) 및 육미지황탕(六味地黃湯) 약침(藥鍼)이 생쥐의 성장(成長)에 미치는 영향(影響)

  • Kim, Min-Jung;Hong, Kwon-Eui
    • Journal of Pharmacopuncture
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    • v.9 no.3
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    • pp.105-116
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    • 2006
  • Objectives : To investigate the effect of Ga-mee-Gwui-ryong-tang herbal acupuncture(GR-HA) at GB39 and ST36 and the effect of Yuk-mee-ji-hwang-tang herbal acupuncture(YM-HA) at GB39 and KI10 on growth in mice. Methods : Mice were divided into 7 group(n=10) ; saline-ST36, saline-GB39 and KI10, GR-HA-ST36 group treated with GR-HA at right ST36, GR-HA-GB39 group treated with GR-HA at right GB39, YM-HA-GB39 group treated with YM-HA at right GB39, YM-HA-KI10 group treated with YM-HA at right KI10. Saline-ST36 group, saline-GB39 group and saline-KI10 group were injected with saline at right ST36, GB39, KI10 respectively. Saline injection and HA were performed 3 times a week for 18 days. The length(total height, body length and tail length), weight and the protein efficiency ratio were measured as well as IGF-1 level in serum. Results : 1. GR-HA at GB39 and GR-HA at ST36 promoted growth in weight, tail length and total height but there was no statistical significance. 2. GR-HA at GB39 significantly promoted protein efficiency on the 14th day and GR-HA at ST36 on the 3rd day. 3. GR-HA at GB39 significantly increased serum IGF-1. GR-HA at ST36 increased IGF-1 slightly but with no statistical significance. 4. YM-HA at GB39 and YM-HA at KI10 promoted growth in weight, height, tail length and total height but there was no statistical relevance. 5. YM-HA at GB39 and YM-HA at KI10 significantly promoted protein efficiency on the 14th day. 6. YM-HA at GB39 and YM-HA at KI10 significantly increased serum IGF-1. Serum IGF-1 level of YM-HA-KI10 group was significantly higher than that of YM-HA-GB39 group. 7. Serum IGF-1 level of GR-HA-GB39 group was significantly higher than that of YM-HA-GB39 group. Conclusions : GR-HA and YM-HA both may promote growth. This study suggests that herbal acupuncture at GB39 is more effective with Gwui-ryong-tang than Yuk-mee ji-hwang-tang to promote growth. It also suggests that Yuk-mee ji-hwang-tang herbal acupuncture is more effective at KI10 than at GB39.

I. Morphological Studies on the Ear Characters of Korean Indigenous Corn Lines (재래종 옥수수 수집종에 대한 특성조사)

  • Bong-Ho Choe;In-Sup Lee;Ja-Sung Cho;Jong-Sung Park
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.23 no.1
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    • pp.36-43
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    • 1978
  • Ears collected from 500 regions were phenotypically observed for their ear and kernel characters. Characters studied included ear shape, kernel color, kernel density, ear row number, starch quality, pop corn and waxy corn, ear length, ear diameter, kernel length, kernel width, kernel weight, ear weight, and 100 kernel weight. The Korean local corn collected were mostly flint type and were very diverse in all the characters studied. The collected local corn would be very promising for providing good germplasm for corn breeding in the future.

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