• Title/Summary/Keyword: WAF

Search Result 179, Processing Time 0.023 seconds

Application of Well Allocation Factor for Injection Optimization of Waterflooding (수공법 주입량 최적설계를 위한 Well Allocation Factor 적용 연구)

  • Yoon, Su-Jin;Kang, Pan-Sang;Lim, Jong-Se
    • Journal of Energy Engineering
    • /
    • v.24 no.4
    • /
    • pp.1-10
    • /
    • 2015
  • For successful operation of waterflooding which is one of secondary recovery methods, suitable water injection allocation is important to increase oil recovery. Well allocation factor(WAF) which is one way to quantify the injector and producer connectivity, is utilized to allocate water injection of waterflooding. Static WAF cannot represent the field condition and can induce incorrect value. To compensate for limitation of static WAF, modified WAF which includes several parameters that affect patterns including well radius, distance between wells, and injection rates is proposed. In this study, static and modified WAFs were applied to injection optimization of waterflooding and results by each WAF were compared. In case of modified WAFs, produced water were less and produced oil were more than case of static WAF especially in big change of distance between producer and injector. Therefore, modified WAFs can allocate water injection more efficiently than static WAF.

Asiatic Acid Promotes p21WAF1/CIP1 Protein Stability through Attenuation of NDR1/2 Dependent Phosphorylation of p21WAF1/CIP1 in HepG2 Human Hepatoma Cells

  • Chen, Jin-Yuan;Xu, Qing-Wen;Xu, Hong;Huang, Zong-Hai
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.2
    • /
    • pp.963-967
    • /
    • 2014
  • Previous studies have suggested anti-tumor effects of asiatic acid in some human cancer cell lines. This agent is reported to increase the levels of $p21^{WAF1/CIP1}$ in human breast cancer cell lines. However, the molecular mechanisms have not been established. Here we report that asiatic acid up-regulates $p21^{WAF1/CIP1}$ protein expression but not the level of $p21^{WAF1/CIP1}$ mRNA in HepG2 human hepatoma cells. Furthermore, we found that the asiatic acid induced increase of $p21^{WAF1/CIP1}$ protein was associated with decreased phosphorylation (ser-146) of $p21^{WAF1/CIP1}$. Knockdown of NDR1/2 kinase, which directly phosphorylates $p21^{WAF1/CIP1}$ protein at ser-146 and enhances its proteasomal degradation, increased the levels of $p21^{WAF1/CIP1}$ protein and eliminated the regulation of $p21^{WAF1/CIP1}$ stability by asiatic acid. At the same time, the expression of NDR1/2 kinase decreased during treatment with asiatic acid in HepG2 cells. Moreover, asiatic acid inhibited the proliferation of HepG2 cells, this being attenuated by knockdown of $p21^{WAF1/CIP1}$. In conclusion, we propose that asiatic acid inhibits the expression NDR1/2 kinase and promotes the stability of $p21^{WAF1/CIP1}$ protein through attenuating NDR1/2 dependent phosphorylation of $p21^{WAF1/CIP1}$ in HepG2 cells.

Ingestion Responses of the Copepod Tigriopus japonicus Exposed to the Water Accommodated Fraction (WAF) and Chemically Enhanced WAF (CEWAF) of Crude Oil (유류 오염에 의한 요각류 Tigriopus japonicus의 섭식반응)

  • Lee, Kyun-Woo
    • Journal of Marine Life Science
    • /
    • v.1 no.2
    • /
    • pp.121-125
    • /
    • 2016
  • This study examined the feeding response of the harpacticoid copepod, Tigriopus japonicus exposed to WAF or CEWAF to understand whether decreased feeding of the copepod by oil exposure is induced by food avoidance or medium toxicity. In the medium without WAF, there was no difference in the ingestion rate of the copepod among all polluted diets those were exposed to different concentrations of WAF. The present of WAF in the medium however caused a decrease in the ingestion rate at 100% WAF treatment. In the mixed diet treatment with adhesive diatoms and Tetraselmis suecica, T. japonicus had significantly lower ingestion rate on adhesive diatoms than on others in the medium with CEWAF. As a result, decreased ingestion of T. japonicus by oil exposure was caused by oil toxicity in medium, which may not have directly related with an avoidance of polluted food organisms.

Effects of ultraviolet radiation on the toxicity of water-accommodated fraction and chemically enhanced water-accommodated fraction of Hebei Spirit crude oil to the embryonic development of the Manila clam, Ruditapes philippinarum

  • Lee, Chang-Hoon;Sung, Chan-Gyoung;Kang, Sin-Kil;Moon, Seong-Dae;Lee, Ji-Hye;Lee, Jong-Hyeon
    • The Korean Journal of Malacology
    • /
    • v.29 no.1
    • /
    • pp.23-32
    • /
    • 2013
  • The purpose of this study is to evaluate the effects of oil dispersant and ultraviolet (UV) radiation on the toxicity of crude oil. The toxicity of water-accommodated fraction (WAF) and chemically enhanced water-accommodated fraction (CEWAF) of Hebei Spirit crude oil was investigated in the embryo of the Manila clam, Ruditapes philippinarum with- and without ultraviolet radiation. The WAF and CEWAF with- and without UV radiation affected significantly the embryonic development of R. philippinarum. The EC50s of WAF without UV, WAF with UV, CEWAF without UV, and CEWAF with UV were 2.82, 0.79, 1.60, and 0.45 g/L, respectively. CEWAF was 1.6 times more toxic than WAF. UV radiation increased crude oil toxicity to 3.6 times for both WAF and CEWAF. The oil dispersant and UV radiation did not affect the acute toxicity to the embryo but retarded the period of embryonic development up to 26%. R. philippinarum proved to be a sensitive species to reflect the toxic effects of oil spill combined with oil dispersant and UV radiation. It is suggested that the chemical analyses on the WAF and CEWAF is important for the identification and quantitative explanation of the phototoxic compounds in crude oil.

Clinical Analysis According to $p21^{Waf1/Cip1}\;and\;p27^{kip1}$ Expression in Gastric Cancer (위암에서의 $p21^{Waf1/Cip1}\;and\;p27^{kip1}$ 단백 발현)

  • Kim, Sin-Sun;Park, Yong-Geun;Jun, Kyong-Hwa;Jung, Hun;Song, Gyo-Young;Kim, Jin-Joo;Chin, Hyung-Min;Kim, Wook;Park, Cho-Hyun;Park, Seung-Man;Lim, Keun-Woo;Kim, Seung-Nam;Jeon, Hae-Myung
    • Journal of Gastric Cancer
    • /
    • v.6 no.1
    • /
    • pp.36-42
    • /
    • 2006
  • Purpose: The $p21^{Waf1/Cip1}$ protein Inhibits the cell cycle by Inhibiting the phosphorylation at the $G1{\rightarrow}S$ check point, and the $p27^{kip1}$ protein similarly performs the suppressor function by controlling the p27-mediated G1 arrest. In this study, we analysed the clinical status and survival rates in correlations with p21 and p27 expression patterns in gastric cancer. Materials and Methods: Between 1993 and 1997, 192 patients who underwent surgeries in Catholic Medical Center were analysed retrospectively in this study. Immunohistochemical staining was performed and if the nuclei of the tumor cells were stained, we assumed those as positive results. Statistical analysis was based on clinicopathological findings and differences in survival rates. Results: The expression rate of p27 was 28.1% and 15.6% in p21 each. The ratio of T1-2(80.0%) was significantly high in p21 (+), but the ratio of T3-4 (50.6%) was slightly high in p21 (-). There was no statistical significance regarding other factors. The results in p27 was not much different from expression rate of p21 in T-stage. In addition, p27 expression in diffuse type (91.3%) was higher than in intestinal type (62.7%) by Lauren's classification (P<0.05). Also, there was no statistical significance in other factors. In the correlation of p21 and p27, p27 was positive when p21 was positive (53.5%). Conversely, p27 was negative when p21 was negative (76.5%, p<0.05). In the p21 and p27 combination test, there was higher rate of T1-2 (87.5%) in p21 (+)/p27 (+), and higher rate of T3-4 (58.1%) in p21 (-)/p27 (-) (P<0.05). Results showed higher rate of intestinal type (100%) in p21 (+)/p27 (+), and diffuse type (87.0%) was dominant in p21 (-)/p27 (-) (P<0.05) by Lauren's classification. Moreover, there was no statistical significance in the 5-year survival rate in the expression of p21 and p27, and the 5-year survival rate was highest in the case of p21 (+)/p27 (+) without statistical significance. Conclusion: In our study, $p21^{Waf1/Cip1}\;and\;p27^{kip1}$ expressed similar patterns. The expression of $p21^{Waf1/Cip1}\;and\;p27^{kip1}$ affected the degree of invasiveness of the tumor, and. Combined examination result revealed the correlation of $p21^{Waf1/Cip1}\;and\;p27^{kip1}$ with Lauren's classification and depth of invasion of the tumor. However, we assumed that little difference between the survival rates depending on expression of $p21^{Waf1/Cip1}\;and\;p27^{kip1}$ has limited their value as predictable prognostic indicators.

  • PDF

Analysis Model of Write Amplification Factor on Flash Memory (플래시 메모리에서 쓰기 증폭 인자 분석 모델)

  • Lee, Sang-Yup;Kim, Se-Woog;Jeon, Jeong-Ho;Choi, Jong-Moo;Yang, Joong-Seob;Mo, Yeon-Jin;Shin, Young-Kyun
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2011.06a
    • /
    • pp.551-554
    • /
    • 2011
  • 덮어쓰기 제약(overwirte limitation)과 삭제 횟수 제한(limitted erase cycle)이 있는 플래시 메모리의 특징이 의하여, 플래시 메모시는 시스템에서 요청한 쓰기 요청보다 많은 수의 쓰기 연산을 수행하게 되는데, 시스템에서 요청한 쓰기요청과 실제 쓰기 연산 간의 비율을 쓰기 증폭 인자(Write Amplification Factor, 이후 WAF)라 한다. WAF는 성능과 신뢰성에 중요한 요소로 본 논문에서는 WAF를 예측 할 수 있는 분석모델을 제안한다. 제안된 모델은 페이지 사상 FTL, 블록 사상 FTL, 혼합 사상 FTL 등 다양한 FTL에서 WAF를 예측 할 수 있으며, 예측에 사용되는 매개 변수로 이용율(utilization), 무작위율(randomness), 연관도(Associativity)만을 사용하여 단순하다는 특성이 있다. 본 논문은 실제 Linux 환경에서 측정한 WAF와 비교 분석 결과 제안된 모델이 WAF를 정확히 예측 할 수 있음을 발견하였다.

Promoting the regional cultural industries through the animation festival : WAF case study (애니메이션 페스티벌 공모전과 지역문화산업 육성전략의 연계 모델 연구 : WAF 사례 분석을 중심으로)

  • Yim, Hak-Soon
    • Cartoon and Animation Studies
    • /
    • s.14
    • /
    • pp.129-150
    • /
    • 2008
  • The article concerns the relationship between the animation festival and the regional cultural industries. In particular, the article studies the WAF(Web Animation Festival) case, in which has hold since 2004 by the Gwangju Information & Culture industry Promotion Agency in the city of Gwangju. The WAF case will be examined in terms of the promotion of the selected web cartoons and animations in the festival competition. As a result, the competion festival has been managed in connection with the support programs for the promotion of the regional cultural industries. In the process, the Gwangju Information & Culture industry Promotion Agency has sought to connect the selected arts works with the CEOs in the field of content business and media business. The article concludes the WAF need to be reestablished in the context of the development of the Gwangu cultural industries cluster and the reinforcement of the international exchange and networking through the grand project of Asian Cultural Capital Gwangu.

  • PDF

Weighted Averaged Flux Method for Computation of Shallow Water Equations (WAF 기법을 이용한 천수방정식 해석)

  • Kim, Woo-Gu;Jung, Kwan-Sue;Kim, Jae-Han
    • Journal of Korea Water Resources Association
    • /
    • v.36 no.5
    • /
    • pp.777-785
    • /
    • 2003
  • A numerical model for the solution of two-dimensional free surface flow is developed on unstructured grid. By using fractional step method, the two-dimensional shallow water equations (SWE) are treated as two one-dimensional problems. Thus, it is possible to simulate computational hydraulic problems with higher computational efficiency. The one-dimensional problems are solved using upwind TVD version of second-order Weighted Averaged Flux (WAF) scheme with HLLC approximate Riemann solver. The numerical oscillations which are common with second-order numerical scheme are controlled by exploiting WAF flux limiter, Some idealized test problems are solved using this model and very accurate and stable solutions are obtained. It can be concluded as an efficient implement for the computation of SWE including dam break problems that concerning discontinuities, subcritical and supercritical flows and complex domain.

The p53-p21Cip1/WAF1 Pathway Is Necessary for Cellular Senescence Induced by the Inhibition of Protein Kinase CKII in Human Colon Cancer Cells

  • Kang, Ji-Young;Kim, Jin Joo;Jang, Seok Young;Bae, Young-Seuk
    • Molecules and Cells
    • /
    • v.28 no.5
    • /
    • pp.489-494
    • /
    • 2009
  • We have previously shown that the down-regulation of protein kinase CKII activity is tightly associated with cellular senescence of human fibroblast IMR-90 cells. Here, we examined the roles of p53 and $p21^{Cip1/WAF1}$ in senescence development induced by CKII inhibition using wild-type, isogenic p53-/- and isogenic p21-/- HCT116 human colon cancer cell lines. A senescent marker appeared after staining for senescence-associated ${\beta}$-galactosidase activity in wild-type HCT116 cells treated with CKII inhibitor or $CKII{\alpha}$ siRNA, but this response was almost abolished in p53- or $p21^{Cip1/WAF1}$-null cells. Increased cellular levels of p53 and $p21^{Cip1/WAF1}$ protein occurred with the inhibition of CKII. CKII inhibition upregulated p53 and $p21^{Cip1/WAF1}$ expression at post-transcriptional level and transcription level, respectively. RB phosphorylation significantly decreased in cells treated with CKII inhibitor. Taken together, this study shows that the activation of the $p53-p21^{Cip1/WAF1}$ pathway acts as a major mediator of cellular senescence induced by CKII inhibition.

Development of a Stress ECG Analysis Algorithm Using Wavelet Transform (웨이브렛 변환을 이용한 스트레스 심전도 분석 알고리즘의 개발)

  • 이경중;박광리
    • Journal of Biomedical Engineering Research
    • /
    • v.19 no.3
    • /
    • pp.269-278
    • /
    • 1998
  • This paper describes a development of efficient stress ECG signal analysis algorithm. The algorithm consists of wavelet adaptive filter(WAF), QRS detector and ST segment detector. The WAF consists of a wavelet transform and an adaptive filter. The wavelet transform decomposed the ECG signal into seven levels using wavelet function for each high frequency bank and low frequency bank. The adaptive filter used the signal of the seventh lowest frequency band among the wavelet transformed signals as primary input. For detection of QRS complex, we made summed signals that are composed of high frequency bands including frequency component of QRS complex and applied the adaptive threshold method changing the amplitude of threshold according to RR interval. For evaluation of the performance of the WAF, we used two baseline wandering elimination filters including a standard filter and a general adaptive filter. WAF showed a better performance than compared filters in the noise elimination characteristics and signal distortion. For evaluation of WAF showed a better performance than compared filters in the noise elimination characteristics and signal distortion. For evaluation of results of QRS complex detection, we compared our algorithm with existing algorithms using MIT/BIH database. Our algorithm using summed signals showed the accuracy of 99.67% and the higher performance of QRS detection than existing algorithms. Also, we used European ST-T database and patient data to evaluate measurement of the ST segment and could measure the ST segment adaptively according to change of heart rate.

  • PDF