• 제목/요약/키워드: Paraffin

검색결과 989건 처리시간 0.026초

파라핀 슬러리를 사용한 다칩모듈의 냉각특성 (Cooling characteristics of the multichip module using paraffin slurry)

  • 조금남;최민구
    • 대한기계학회논문집B
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    • 제22권6호
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    • pp.888-898
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    • 1998
  • The present study investigated the effects of the experimental parameters on the cooling characteristics of the multichip module cooled by the indirect liquid cooling method using water and paraffin slurry. The experimental parameters are mass fraction of 2.5 ~ 7.5% for paraffin slurry, heat flux of 10 ~ 40 W/cm$^{2}$ for the simulated VLSI chips and Reynolds numbers of 5,300 ~ 15,900. The apparatus consisted of test section, paraffin slurry maker, pump, constant temperature baths, flowmeter, etc. The test section made of in-line, four-row array of 12 heat sources for simulating 4 * 3 multichip module which was flush mounted on the top wall of a horizontal rectangular channel with the aspect ratio of 0.2. The inlet temperature was 20 deg. C for all experiments. The size of paraffin slurry was constant as 10 ~ 40 .mu.m befor and after the experiment. The chip surface temperatures for paraffin slurry with the mass fraction of 7.5% showed lower by 16 deg. C than those for water when the heat flux is 40 W/cm$^{2}$. The local heat transfer coefficients for the paraffin slurry with the mass fraction of 7.5% were larger by 17 ~ 25% than those for water at the first and the fourth row. The local heat transfer coefficients reached to a row-number-independent, thermally fully developed value approximately after the third row. The local Nusselt numbers at the fourth row for paraffin slurry with the mass fraction of 7.5% were larger by 23 ~ 29% than those for water.

Paraffin wax/LDPE 혼합 연료의 연소 특성에 관한 연구 (A Study on the Combustion Characteristics of Paraffin wax/LDPE Blended fuel)

  • 김수종;조정태;이정표;문희장;성홍계;김진곤
    • 한국추진공학회지
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    • 제14권2호
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    • pp.29-38
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    • 2010
  • 하이브리드 로켓을 위한 파라핀 왁스/LDPE 혼합 연료에 관한 실험적 연구를 수행하였다. 혼합 연료 의 성능 평가를 위해 혼합 연료의 다양한 연소 특성을 순수 파라핀, HTPB, HDPE, SP-1a 연료와 비교하였다. 순수 파라핀의 후퇴율은 HDPE에 비해 large-scale과 lab-scale 모터에서 각각 10.2, 9.8배 증가 하였다. Lab-scale 혼합 연료의 후퇴율은 HDPE에 비해 3.4배 증가하여 HTPB, HDPE 연료보다는 높은 후퇴율을 나타냈으나 순수 파라핀, SP-1a에 비해서는 낮은 후퇴율을 나타냈다. 혼합 연료의 특성속도와 비추력은 순수 파라핀, HTPB, HDPE 보다 높았고 SP-1a 연료와 대등하였다. 이로부터 혼합 연료가 효과적인 하이브리드 로켓 연료가 될 수 있음을 확인하였다.

Enhanced In-situ Mobilization and Biodegradation of Phenanthrens from Soil by a Solvent/Surfactant System

  • Kim, Eun-Ki;Ahn, Ik-Sung;L.W.Lion;M.L.Shuler
    • Journal of Microbiology and Biotechnology
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    • 제11권4호
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    • pp.716-719
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    • 2001
  • The mobilization and biodegradation of phenanthrene in soil was enhanced by using paraffin oil, which was stabilized by the addition of a surfactant (Brji 30). The ratio of paraffin oil/Brij 30 was determined by measuring the change in the critical micelle concentration. When only surfactant was used, the stabilized paraffin oil emulsion could dissolve more phenanthrene in the water phase. Column experiment showed increased phenanthrene mobilization from the contaminated soil. The phenanthrene mobilized in the paraffine oil/Brij 30 emulsion was biodegraded faster than that in water phase or surfactant solution. This result indicates that a paraffin oil/surfactant system can be effectively used for the removal of PAH from contaminated soil.

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진동분광실험을 이용한 n-Paraffin혼합물의 결정화에 관한 연구 (Vibrational Spectroscopic Studies of Crystallization in Mixed n-Paraffins)

  • 김도균;임현주;최선남;김성수;송기국
    • 폴리머
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    • 제26권6호
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    • pp.752-758
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    • 2002
  • 사슬길이가 서로 다른 두 종류의 n-paraffin 혼합물이 결정을 형성할 때 사슬의 움직임과 형성된 라멜라의 구조를 조사하기 위하여 FTIR, FT-Raman, XRD 실험방법을 이용하였다. FTIR crystal field splitting, Raman longitudinal acoustic mode, 그리고 SAXS long period 측정 결과들을 비교하여 사슬길이가 다른 두 n-paraffin 사슬이 혼합되어 하나의 라멜라를 형성하거나 분리되어 각각의 라멜라를 형성하는 과정을 연구하였다.

IRB review points for studies utilizing paraffin blocks archived in the pathology laboratory

  • Kim, Yong-Jin;Jeong, Chang Rok;Park, Jeong Sik
    • Journal of Yeungnam Medical Science
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    • 제35권1호
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    • pp.36-39
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    • 2018
  • In the personalized medicine era, utilizing paraffin blocks in pathology archives for investigating human diseases has come into the limelight. This archived material with clinical data will reduce the research time and could prevent new patient recruitment to obtain tissue for research. However, the clause indicating the necessity of consent from human material providers in the Korean Bioethics and Safety Act has made the Institutional Review Board (IRB) deny permission to use paraffin blocks for research without consent, and alternatively to get the same before starting an experiment. Written consent may be waived off in studies using paraffin blocks with anonymous status or conditions not linked to personal information by applying the paragraph 3, article 16 of the current Bioethics and Safety Act. Also, the IRB should recommend researchers to preserve the blocks as medical records of patients in long-term archives.

시멘트-모래-파라핀 왁스 혼합물을 이용한 축열에 관한 연구 (A Study on the Latent Heat Storage Unit Using Cement-Sand_Paraffin Wax Mixture)

  • 유호선;노승탁
    • 대한설비공학회지:설비저널
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    • 제9권3호
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    • pp.161-169
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    • 1980
  • In order to enhance the thermal energy storage capacity of cement mortar and to improve the effective thermal conductivity of paraffin waxes, cement- sand- paraffin wax mixture was investigated. By means of finite difference method, the transient temperature distribution in a hollow cylinder with phase change using average composite properties was obtained, and compared with experimental results. It was shown that the heat absorbed by mixture with $25\%$ paraffin fraction was as much as $50\%$ more than either a concrete mortar or pure paraffin wax in the case of ${\Delta}T=\;18.25^{\circ}C$.

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보존된 파라핀 블록에서 핵산 추출기법에 관한 연구 (he Study of Nucleic Acid Extraction Method from Archival Paraffin Blocks)

  • 주경웅
    • 대한임상검사과학회지
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    • 제40권2호
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    • pp.113-117
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    • 2008
  • It designed a study to examine the efficiency of DNA and RNA extraction from archival formalin-fixed, paraffin-embedded tissues using an non-heating and heating method. Archival paraffin blocks of liver, kidney, colon were randomly selected. Each paraffin block was prepared in 20 microtubes. For each paraffin blocks were tested non-heating DNA extraction to 10 microtubes and heating protocol under pH 7.0 and $100^{\circ}C$ to 10 microtubes. Evaluation of the results of DNA extraction was carried out by measuring concentration by UV spectrophotometry and then PCR amplification. DNA extraction content that non-heating method was liver $5{\pm}0.7{\mu}g/mL$, kidney $2{\pm}0.3{\mu}g/mL$, colon $6{\pm}0.4{\mu}g/mL$ and heating method was liver $12{\pm}0.6{\mu}g/mL$, kidney $7{\pm}0.5{\mu}g/mL$, colon $10.{\pm}0.3{\mu}g/mL$. Successful RNA extraction was observed, by ${\beta}$-actin amplification, in 46.7% sections for samples treated by the heating method versus 30.0% using non-heating DNA extraction. The extracted nucleic acid showed better values for samples heated at $100^{\circ}C$. Therefore heating extraction of nucleic acid is reliable, quick and efficiency.

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파라핀계 하이브리드 로켓 연료의 연소 특성 (Combustion Characteristics of the Paraffin-Based Hybrid Rocket Fuel)

  • 김수종;조정태;김기훈;김학철;우경진;이정표;문희장;성홍계;김진곤
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2009년도 춘계학술대회 논문집
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    • pp.225-228
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    • 2009
  • 하이브리드 로켓에서 파라핀계 연료의 연소 특성을 HDPE 연료와 비교하였다. 순수 파라핀 왁스를 사용한 경우 후퇴율은 HDPE에 비해 12.1배로 매우 빠른 후퇴율을 보였으나 특성 속도는 매우 낮았다. 순수 파라핀에 10 wt%의 LDPE를 블렌딩한 연료의 경우 순수 파라핀에 비해 후퇴율이 감소한 반면 HDPE에 비해서는 3.5배로 빠른 후퇴율을 보이면서도 특성속도는 증가되었다. 이를 통해 순수 파라핀에 폴리머계 연료를 블렌딩함으로써 연소 효율을 개선할 수 있음을 확인하였다.

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The Effect of Paraffin Treatment with Exercise on Muscle Strength and Fatigue of the Hand According to the Use of Smartphone

  • Kim, Su-Hyon
    • The Journal of Korean Physical Therapy
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    • 제32권4호
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    • pp.198-202
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    • 2020
  • Purpose: This study examined the effects of a paraffin treatment with exercise on the muscle strength and fatigue of the hand according to the use of smartphones. Methods: The measurement subjects were 30 healthy males in their 20s who were divided randomly into the control and paraffin treatment groups. A typing exercise using a smartphone was performed. The pinch grip force was measured to evaluate the muscle strength of the thumb, and muscle fatigue analysis using electromyography was performed to analyze muscle fatigue. Results: The functional changes to the arm and the fatigue of the hand through the use of a smartphone were examined to determine the effects of the paraffin treatment. The dominant hand-pinch grip force test did not show a significant difference, but the non-dominant hand-pinch grip force test showed a significant difference between the groups (p=0.030). In the dominant hand fatigue test, there was a significant difference between the groups (p=0.037). In the non-dominant hand, there was a significant difference between time (p=0.012) and the groups (p<0.001). Conclusion: The effects of paraffin intervention on the hand muscle strength and fatigue due to repeated use of the smartphone were confirmed. These results can be used as a basis for clinical use and can be a guide for the correct use of smartphones, which are essential in modern life.

파라핀조직을 이용한 미토콘드리아 DNA 돌연변이 확인 (Identification of a Mitochondrial DNA Mutation in Paraffin-Embedded Muscle Tissues)

  • 김상호;유석호
    • 생명과학회지
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    • 제14권2호
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    • pp.296-300
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    • 2004
  • 환자의 생조직, 얼린 조직 혹은 혈액이 없는 경우에, formalin으로 고정된 파라핀조직을 이용하여 미토콘드리아 돌연변이를 확인할 수 있는지를 조사하였다. MELAS 환자 4명의 파라핀조직을 택해 이들 조직으로부터 DNA를 추출하여 대부분의 MELAS 환자 미토콘드리아 DNA의 tRN $A^{Leu(UUR)}$ gene의 3243지역에서 발견되는 Adenine의 Cuanine으로의 염기치환을 확인하고자 하였다. 실험결과 3명의 환자에게서 이 점 돌연변이를 확인할 수 있어 이들 파라핀조직의 상태가 좋은 것으로 여겨져 미토콘드리아 DNA 돌연변이 연구에 파라핀조직을 활용할 수 있을 것으로 보인다.다.