• Title/Summary/Keyword: 고 pH

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Screening method using the cells deviation for Li-ion battery pack of the high power application (고출력 어플리케이션의 배터리 팩에 적합한 셀간 편차를 이용한 스크리닝 기법)

  • Lee, P.Y.;Lee, D.Y.;Pack, J.H.;Kim, J.H.;Lim, C.W.
    • Proceedings of the KIPE Conference
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    • 2017.11a
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    • pp.157-158
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    • 2017
  • 본 논문에서는 고출력 리튬이온 18650 셀(cell) 200개를 사용하여 고출력 어플리케이션의 운용 범위와 동적 특성을 적용한 스크리닝 방법을 제안하였다. 전기적 특성 실험 기반 배터리 용량과 OCV(open circuit voltage)의 요소를 고려한 16개의 내부 파라미터를 추출하고 표준편차 기반 가중치를 선정하였다. 선정된 가중치를 각각의 요소에 적용하여 단위 셀의 대표 값을 결정하고 셀 스크리닝을 수행하였다. 기존의 스크리닝 기법과 제안된 스크리닝 기법을 200개의 단위 셀에 적용하여 두 기법의 차이를 비교 분석하였다.

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Association of ionized magnesium, total magnesium, gestational age, and intraventricular hemorrhage in preterm babies (미숙아에서 이온화 마그네슘, 총 마그네슘과 재태 연령과의 관계 및 뇌실 내 출혈과의 관계)

  • Kim, Tae-Yeon;Lee, Hyun-Hee;Sung, Tae-Jung
    • Clinical and Experimental Pediatrics
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    • v.52 no.10
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    • pp.1140-1146
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    • 2009
  • Purpose:The pathophysiology of magnesium, the second highest common compound in humans, is still unclear, especially in preterm babies. We accessed the association between total magnesium (tMg), ionized Mg (iMg), and gestational age (GA) and that between serum magnesium (sMg) and intraventricular hemorrhage (IVH) in preterm babies. Methods:In all, 119 inborn preterm infants admitted between July 2006 and February 2008 were divided into the IVH group (19) and the control group (100) and were prospectively analyzed. TMg, iMg, pH, total calcium (tCa), and ionized Ca (iCa) levels were determined immediately after delivery or within 3 hours after birth, and their correlation with GA were investigated. Results:TMg was not correlated with GA, tCa, iCa, and pH. IMg was correlated with tMg (r=0.288, P=0.002) and iCa (r=0.212, P=0.021); however, it was not correlated with GA and pH. Mean GA and birth weight were significantly lower (P=0.002) and smaller (P=0.030) in the IVH group. Mean sMg was higher in the IVH group ($2.5{\pm}0.9mg/dL$) than in the control group ($2.1{\pm}0.6mg/dL$) (P=0.021). SMg was a risk factor even after logistic regression analysis (OR, 2.798; 95% C.I., 1.265-6.192; P=0.011). Conclusion:In less than 37-week-old preterm babies, tMg and iMg were similar, regardless of GA. High sMg may be a risk factor for IVH in premature babies, regardless of their exposure to antenatal magnesium.

Development of the pH Inhibition Model Adapting Pseudo Toxic Concentration (CPT) Concept for Activated Sludge Process (의사독성농도 (CPT) 개념을 도입한 활성슬러지 공정 pH 저해 모델 개발)

  • Ko, Joo-Hyung;Jang, Won-Ho;Im, Jeong-Hoon;Woo, Hae-Jin;Kim, Chang-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.11
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    • pp.2037-2046
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    • 2000
  • It has been reported that the inhibition effect of pH on activated sludge follows noncompetitive inhibition kinetics. However. the noncompetitive inhibition kinetic equation can not be directly applied to pH inhibition because of the difficulty in quantification of pH in terms of inhibitor concentration. So, many empirical equations have been developed to describe the pH inhibition effect especially for acidic condition. In this research. the pseudo toxic concentration ($C_{PT}$) concept model to quantify pH inhibition effect on activated sludge was proposed and compared to other existing models. The $C_{PT}$ concept model can explain the reduction of the maximum specific growth rate (${\mu}_{max}$) caused by the pH inhibition more accurately than any other models, at a wide range of pH. The only model parameter. $K_I$ can be easily estimated by Lineweaver-Burk linearization method.

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Histopathological study of acute toxicity of ammonia to the eel, Anguilla japonica in high temperature and pH levels (고수온(高水溫) 고(高)pH에서 뱀장어에 미치는 암모니아 급성독성(急性毒性)의 병리조직학적(病理組織學的) 연구(硏究))

  • Kim, Min-Soo;Yang, Han-Choon
    • Journal of fish pathology
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    • v.9 no.2
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    • pp.147-155
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    • 1996
  • This study was carried out to examine the acute toxic effects of ammonia to the eel, Anguilla japonica in high temperature and pH levels by histopathological observations. The eels of 40 g average body weight were exposed to 4 different concentrations of total ammonia (0, 10, 20, 30 mg/$\ell$) for 24~120 hours. Each concentration was treated under 4 different levels of pH (7.5, 8.0, 8.5, 9.0) and each of these treatments was tested at 2 different temperatures ($27^{\circ}C$, $32^{\circ}C$). Histopathological changes in gill tissues were observed by hematoxylin-eosin stain. As increasing of pH (from 7.5 to 9.0), water temperature (from $27^{\circ}C$ to $32^{\circ}C$), total ammonia concentration (from 0 mg/$\ell$ to 30 mg/$\ell$) and exposure time (from 24 hours to 120 hours), gill discolorated to dark brown with the naked eye and gill tissues showed hypertrophy of gill lamellae, winding of the secondary gill lamellae, epitherial separation and necrosis histopathologically. When gill lamellae epithelium was separated from the blood vessels, gill discolorated to dark brown with the naked eye.

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Synthesis and Characterization of High Surface Area of Zirconia: Effect of pH (고비표면적 지르코니움 산화물의 제조 및 특성 분석: pH 영향)

  • Jeong, Ye-Seul;Shin, Chae-Ho
    • Korean Chemical Engineering Research
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    • v.57 no.1
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    • pp.133-141
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    • 2019
  • High specific surface area zirconia with acid-basic property was synthesized by precipitation using reflux method or hydrothermal synthesis method using ammonium hydroxide solution as precipitant in the range of pH of Zr solution from 2 to 10. The prepared zirconia was characterized by the nitrogen adsorption, X-ray diffraction (XRD), isopropanol temperature programmed desorption (IPA-TPD), scanning electron microscopy and X-ray photoelectron spectroscopy, and the catalytic activity in the IPA decomposition reaction was correlated with the acid-basic properties. When using reflux method, high pH of Zr solution was required to obtain high fraction of tetragonal zirconia, and pure tetragonal zirconia was possible at pH 9 or higher. High pH was required to obtain high specific surface area zirconia, and the hydrous zirconia synthesized at pH 10 had high specific surface area zirconia of $260m^2g^{-1}$ even after calcination at $600^{\circ}C$. However, hydrothermal synthesis with high pressure under the same conditions resulted in very low specific surface area below $40m^2g^{-1}$ and monoclinic phase zirconia was synthesized. High pH of the solution was required to obtain high specific surface area tetragonal phase zirconia. In hydrothermal synthesis requiring high pressure, monoclinic zirconia was produced irrespective of the pH of the solution, and the specific surface area was relatively low. Zirconia with high specific surface area and tetragonal phase was predominantly acidic compared to basicity and only propylene, which was observed as selective dehydration reaction in IPA decomposition reaction, was produced.

Effects of Soil Components Flowed from Upper Banbyun Stream on Turbidity of Imha Reservoir (반변천 상류지역 토양성분의 유입이 임하호 탁도에 미치는 영향)

  • Seo, Eulwon;Kim, Younjung;Hwang, Haeyeon;Kim, Hyunmc;Baek, Seungcheol;Kim, Jongsik
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.4
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    • pp.35-41
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    • 2006
  • This paper analyzed elution and ingredients of soil components which consist of soil and rocks in 6 regions in Yeongyang and Cheongsong to identify substantial matters that cause muddy water in Imha reservoir. We identified that more than 80% of major ingredients in collected soil and rocks are vermiculite(V), illite(I), kaolinite(Ka), quartz(Q), feldspar(F). Sodium and calcium are eluted in large quantities from soil of Sanseong and Cheongki. When calcium is in contact with water, much ions are eluted rapidly. We confirmed these ions are alkali minerals rising pH. We consider clay components distributed in Yeongyang as major cause of muddy water and rising pH of Imha reservoir because its ingredient calcite easily is dissolved in rainwater and splits other mineral particles into ${\mu}m$ sized particles.

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High Cell Density Culture of Micro-algal Dunaliella bardawil (미세조류 Dunaliella bardawil의 고농도 세포배양)

  • 정욱진;왕만식;최승인;정병철;김주곤
    • KSBB Journal
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    • v.14 no.2
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    • pp.160-166
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    • 1999
  • High cell density cultivation of microalga Dunaliella bardawil using nitrogen fed-batch cultures was studied in batch flask. Optimum environmental conditions include concentrated nutrients except NaCl and carbon sources, carbon sources, pH, light, agitation, nitrate and phosphate ions. Cell growth, consumption rates of nitrate and phosphate ions were monitored. Optimal conditions for higher cell density were found to be(in the range tested): 5 times concentrated media(1 times-10 times concentrated media) pH 8.0 (7.0-9.0) white light(blue and red light) 15mM of nitrate (0.94-15mM) 250mM $NaHCO_3$ and $CO_2$ gas. However, the addition of phosphate ions did not enhance the algal maximum cell density and specific growth rate. Nitrate was found to be effective for the cell growth. The maximum cell density of fed-batch culture using nitrate ions in $8.955{\times}106$cells/ml after 189hr incubation.

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Characterization of Functional Kimchi Using Bifidobacterium lactis (Bifidobacterium lactis를 이용한 기능성 김치의 특성)

  • Kim, Tae-Woon;Park, Ae-Kyung;Kim, Gum-Ran;Lee, Jung-Min;Chung, Dae-Kyun;Kim, Hae-Yeong
    • Korean Journal of Food Science and Technology
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    • v.35 no.5
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    • pp.924-927
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    • 2003
  • This study was conducted to investigate the application of bifidobacteria on kimchi. Among several Bifidobacterium species, we selected Bifidobacterium lactis (DSM 10140), which is resistant to oxygen, acid and salt. Bifidobacterium lactis was cultured in a supplemented deMan, Rogosa and Sharpe (SMRS) medium under aerobic conditions. Its acid-tolerance and salt-tolerance were pH 3.0 and 3.5% (NaCl), respectively. The viability of Bifidobacterium lactis added to kimchi was confirmed by PCR, using specific primers on Bifidobacterium lactis. In sensory evaluation, kimchi containing Bifidobacterium lactis showed similar scores in overall acceptability with the control kimchi. Consequently, these results showed that it would be possible to prepare functional kimchi using Bifidobacterium.

A Study on the Synthesis of High-Purity ${\alpha}-Al_2O_3$ Ultra-Fine Powders by Wet Chemical Method (습식 합성법에 의한 고순도 ${\alpha}-Al_2O_3$ 미세분말의 합성 연구)

  • Jin-Ho Choy;Jong-Seok Yoo;Yang-Su Han;Joon Kim;Hyeon-Kook Lee;Hyuk-Nyun Kim
    • Journal of the Korean Chemical Society
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    • v.35 no.3
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    • pp.275-279
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    • 1991
  • Ultra-fine alumina, ${\alpha}-Al_2O_3$, with ${\phi}$ = 0.1∼0.5 ${\mu}$m was obtained from pure ammonium aluminum sulfate(alum) as the thermal decomposition product. Pure alum(> 99.7%) could be prepared by the precepitation and the successive recrystallization in an acidic aqueous solution at pH = 1.5∼2.5, which was theoretically predicted by only considering the concentrations of hydroxide and carbonate for aluminum and sodium in the solution, and also experimentally confirmed as the optimum precepitation condition for alum without forming any impurities like aluminum hydroxide or sodium one.

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Bacillus stearothermophilus 에서 부분 정제한 Cytosine Deaminase 의 특성

  • 장영채;이경형;김성영;조윤래;김종규
    • Korean Journal of Microbiology
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    • v.30 no.4
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    • pp.305-309
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    • 1992
  • Cytosine deaminase (EC 3.5.4.1) from BaciNus stc~urorhermophilus was partially purified 7.2-fold with an overall yield of 52.7%. The partially purified enzyme deiiminated cytosine only.but not 5-methylcytosine and 5-fluorocytosine. The apparent Michaclis constant. Km valuefor cytosine was 5.9 mM. The enzyme was relatively stable in the range of pH 4.0 to 7.0.furthermore extremely thermo-stable : more than 75'X) of the activity was remained afterheating at 80$^{\circ}$C for I0 min at pH 6.5. The enzyme had a pH optimum at around pH7.0 to 7.5. and temperature optimum at 35 to 31$^{\circ}$C. And the activation energ (En value)determined from an Arrhenius plot was 26 Kcal/mol. The enzyme activity was stronglyinhibited by heavy metal ions such as Cd", Hg". Cut' at 1 mM, anJ by o-phenanthroline,and p-chloromcrcuribcnzoate at I mM. But the enrymc activity was activatetl increased byGMP, and CMP at 1 mM.ased by GMP, and CMP at 1 mM.

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