• Title/Summary/Keyword: KOH treatment

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$Mg_2$Ni계 수소저장합금전극의 퇴화거동에 미치는 불화 처리 영향 (Effects of F-treatment on the Degradation of $Mg_2$Ni type Hydrogen Storage Alloy Electrode)

  • 김준성;최재웅;이창래;강성군
    • 한국재료학회지
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    • 제11권4호
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    • pp.294-299
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    • 2001
  • 기계적 합금화 방법을 이용하여 제작한 Ni-MH 전지용 $Mg_2$Ni전극의 표면 불화처리에 대한 전기화학적 충.방전 특성이 조사되었다. 20시간 밀링을 통해 제조된 $Mg_2$Ni합금은 나노결정을 가졌으며 그 $Mg_2$Ni전극의 KOH전해질내에서 충.방전 실험 결과, 초기 방전 용량이 280mAh/g이상으로 증가하였으나 10cyc1e이내에 급격히 퇴화되었다. 전극표면에서 지속적이고 안정한 불화층 형성을 목적으로 KOH용액에 잉여의 불소이온이 첨가된 $Mg_2$Ni전극의 내구성은 크게 향상되었으며 특히 2N KF를 첨가했을 경우 전극의 내구성이 가장 크게 향상되었다. 고율 방전실험의 경우도 그 성능이 90-100mAh/g으로 유지되었다 이러한 내구성 향상의 이유는 표면에 얕고 다공성인 $Mg_2$Ni층의 형성으로 인해 퇴화의 주요인인 Mg(OH)$_2$의 생성이 억제되었기 때문이었다. Effects of the surface fluorination on the electrochemical charge-discharge properties of $Mg_2$Ni electrode in Ni-MH batteries fabricated by mechanical alloying were investigated. After 20h ball milling, Mg and Ni powder formed nanocrystalline $Mg_2$Ni. Discharge capacity of this alloy increased greatly at first one cycle, but due to the formation of Mg(OH)$_2$ passive layer, it showed a rapid degradation in alkaline solution within 10cyc1es. In case of 6N KOH +xN KF electrolyte (x = 0.5, 1, 2), a continuous and stable fluorinated layer formed by adding excess F$^{-}$ ion, increased durability of $Mg_2$Ni electrode greatly and high rate discharge capability(90-100mAh/g). 2N KF addition led to the highest durability of all tested here. The reason of the improvement is due to thin MgF$_2$, which can prevent the $Mg_2$Ni electrode from forming Mg(OH)$_2$layer that is the main cause of degradation.

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카올린나이트로부터 중기공성 ${\gamma}-Al_2O_3$의 제조 및 특성 (Preparation and Characterization of Mesoporous ${\gamma}-Al_2O_3$ Prepared from Kaolinite)

  • 이광현;고형신;김윤섭
    • 한국재료학회지
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    • 제10권12호
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    • pp.845-852
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    • 2000
  • 국내산 kaolinite를 소성한 다음 실리카를 선택적으로 추출하여 중기공성 ${\gamma}-Al_2O_3$를 제조하였다. $1000^{\circ}C$에서 24시간 소성된 kaolinite는 소량의 무정형 실리카와 ${\gamma}-Al_2O_3$으로 이루어진 스피넬 상의 미세구조로 전이되었음을 확인하였다. 다공성 ${\gamma}-Al_2O_3$$25~90^{\circ}C$의 반응온도, 0.5~4h의 추출시간 및 1~8M의 KOH 농도범위에서 무정형 실리카를 선택적으로 용해하여 제조할 수 있었다. $90^{\circ}C$, 1시간 및 4M의 KOH 농도조건에서 얻어진 ${\gamma}-Al_2O_3$는 약 $40~80{\AA}$ 정도의 매우 좁은 하나의 기공크기 분포를 가지고 있었으며, mesopore의 기공이 많이 생성되었다. 비표면적은 $250\textrm{m}^2/g$이고, 총 기공부피는 $0.654\textrm{cm}^3/g$로 나타났다.

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은행 껍질 기반 활성탄의 메틸오렌지 흡착 특성 (Adsorption Characteristics of Methyl Orange on Ginkgo Shell-Based Activated Carbon)

  • 이정문;이은지;심왕근
    • 공업화학
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    • 제33권6호
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    • pp.636-645
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    • 2022
  • 이 연구에서는 은행껍질기반 활성탄으로 음이온성 염료인 메틸오렌지(MO)의 흡착 특성을 조사하였다. 이를 위해 은행껍질과 대표적인 화학활성화제인 수산화칼륨(KOH)을 이용하여 서로 다른 기공 특성을 지닌 다공성 활성탄(GS-1, GS-2, GS-4)을 제조하였다. 제조한 활성탄의 구조적 특성값과 KOH 혼합비율과의 상관관계는 질소 흡/탈착등온선으로 조사하였다. 활성탄에 대한 MO 흡착 평형 실험은 서로 다른 pH (pH 3~11) 및 온도(298~318 K) 조건에서 실시하였으며 그 결과를 Langmuir, Freundlich, Sips 및 온도 의존 Sips식으로 살펴보았다. 그리고 Langmuir 무차원 분리계수값으로 제조한 활성탄의 MO 흡착처리공정의 타당성을 조사하였다. 흡착에너지분포함수(AED)로 비교 분석한 활성탄에 대한 MO의 불균일 흡착 특성은 온도와 활성탄의 구조적 특성과 밀접한 관련이 있었다. 서로 다른 온도에서 수행한 회분식 흡착 속도 실험 결과는 외부물질전달, 입자 내 확산 및 활성사이트의 흡착을 고려한 균일표면확산모델(HSDM)로 만족스럽게 설명할 수 있었다. 또한 표면확산계수값을 Arrhenius 플롯으로 나타내어 구한 활성화에너지와 흡착에너지분포 함수값과의 상관관계를 살펴보았다. 그리고 Biot 수를 이용하여 제조한 활성탄에 대한 MO의 흡착 공정 메커니즘을 평가하였다.

유용미생물을 적용한 선박오수용 SBR공정에 관한 연구 (Shipboard sewage treatment by Sequence Batch Reactor utilizing Beneficial Microorganisms)

  • 김인수;이언승;하신영;오염재;;고성철
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2010년도 추계학술대회
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    • pp.36-37
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    • 2010
  • 본 연구는 선박용 오폐수처리장치 개발을 위하여 기존의 활성슬러지로 운영하는 SBR공법에 유용미생물제제(BM)를 투입하여 Lab scale의 기초 실험을 수행하였다. 장치 운영 결과 BM 도입 시 SBR의 단일 공정으로 IMO의 규제 기준을 모두 만족하였으며, 오염물질의 처리 효율 향상과 더불어 안전적인 유출수질을 나타내었다. 또한 생물학적 처리 시 발생할 수 있는 악취 문제와 미생물의 효과적인 제어가 가능하여 오수처리 공정 관련 전문가가 동승할 수 없는 선박이라는 특수 환경을 고려할 때 BM의 적용은 매우 유용할 것으로 판단된다.

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간, 담도, 췌장의 진행암으로 한방병원에 내원한 환자의 삶의 질(FACT-G)에 대한 분석 (A Study on Quality of Life of Advanced Hepatobiliary and Pancreatic Cancer patients Administered with Traditional Korean Cancer Treatment)

  • 최철민;고병희;김세현;최원철;이수경
    • 대한한의학회지
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    • 제29권4호
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    • pp.30-38
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    • 2008
  • Objectives: The main goals of cancer treatment are improvement of quality of life and survival prolongation. There is a limitation to prolonging the survival time in hepatobiliary and pancreatic cancer. The purpose of this study was to evaluate the quality of life of hepatobiliary and pancreatic cancer patients who visited for traditional Korean cancer treatment. Methods: We evaluated the quality of life of 23 hepatobiliary and pancreatic cancer patients who visited for oriental medicine treatment at East-West Neo Medical Center from June to October of 2007. FACT-G (Functional Assessment Cancer Therapy-General), used in this study, is a scale for evaluation of QOL confirmed validity and reliability, popularly used in many countries to evaluate QOL of cancer patients. Results: The average age of enrolled patients was 57. There were 10 hepatocellular carcinoma patients, 7 pancreatic cancer patients, 6 biliary tract cancer patients. Twenty one patients were in stage IV and 20 patients had distant metastases. By Sasang constitution, Taeumin were 7, Soyangin were 8, and Soeumuin were 8. The baselines of FACT-G score in the first visit were from 34.33 to 85, and the mean score was 67.3. The mean score of FACT-G in hepatocellular carcinoma patients was 67.5, that of pancreatic cancer patients was 62.5, and that of biliary tract cancer patients was 71. Conclusions: This study is valuable as an initial QOL study of hepatobiliary and pancreatic cancer patients who visited an oriental medical clinic. We believe that consistent studies will be necessary to demonstrate oriental treatment-related quality of life with hepatobiliary and pancreatic cancer.

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Problems Related to the Act on Decisions on Life-Sustaining Treatment and Directions for Improvement

  • Heo, Dae Seog;Yoo, Shin Hye;Keam, Bhumsuk;Yoo, Sang Ho;Koh, Younsuck
    • Journal of Hospice and Palliative Care
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    • 제25권1호
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    • pp.1-11
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    • 2022
  • The Act on Decisions on Life-Sustaining Treatment has been in effect since 2018 for end-of-life patients. However, only 20~25% of deaths of terminally ill patients comply with the law, while the remaining 75~80% do not. There is significant confusion in how the law distinguishes between those in the terminal stage and those in the dying process. These 2 stages can be hard to distinguish, and they should be understood as a single unified "terminal stage." The number of medical institutions eligible for life-sustaining treatment decisions should be legally expanded to properly reflect patients' wishes. To prevent unnecessary suffering resulting from futile life-sustaining treatment, life-sustaining treatment decisions for terminal patients without the needed familial relationships should be permitted and made by hospital ethics committees. Adult patients should be permitted to assign a legal representative appointed in advance to represent them. Medical records can be substituted for a patient's judgment letter (No. 9) and an implementation letter (No. 13) for the decision to suspend life-sustaining treatment. Forms 1, 10, 11, and 12 should be combined into a single form. The purpose of the Life-sustaining Medical Decisions Act is to respect patients' right to self-determination and protect their best interests. Issues related to the act that have emerged in the 3 years since its implementation must be analyzed, and a plan should be devised to improve upon its shortcomings.

복부비만에 활용되는 침치료에 대한 국내외 연구동향 (A Review of Clinical Studies on Acupuncture Application for Abdominal Obesity)

  • 고수민;송미연;정원석;김현석;신우철;김세윤;서준원;조재흥
    • 한방비만학회지
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    • 제23권2호
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    • pp.125-135
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    • 2023
  • Objectives: The purpose of this study was to review current research trends and to provide basic data for the guideline of the acupuncture treatment for abdominal obesity in the clinic. Methods: Publications related to acupuncture treatment for abdominal obesity were retrieved from 9 databases (PubMed, Embase, Scopus, Cochrane Library, Oriental Medicine Advanced Searching Integrated System, Korean studies Information Service System, Research Information Sharing Service, DataBase Periodical Information Academic, National Discovery for Science Library). Extracted studies were analyzed in terms of publication year, study type, treatment method, acupoint and evaluation method. Results: There were 19 studies about acupuncture treatment applied to abdominal obesity. Electroacupuncture and acupoint catgut embedding therapy was the most frequently studied treatment method. ST25, CV12, SP15, CV6, CV4 was the most frequently used acupoint. Body weight, body mass index, waist circumference and waist-hip ratio was the most frequently used evaluation method. Conclusions: This review identified acupuncture application for abdominal obesity. However, well-designed and conducted clinical trials will be more needed to develop acupuncture treatment for abdominal obesity.

Surgery versus Conservative Treatment for Spontaneous Supratentorial Intracerebral Hemorrhage in Spot Sign Positive Patients

  • Kim, Hui-Tae;Lee, Jong-Myong;Koh, Eun-Jeong;Choi, Ha-Young
    • Journal of Korean Neurosurgical Society
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    • 제58권4호
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    • pp.309-315
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    • 2015
  • Objective : An advantage of surgical treatment over conservative treatment of spontaneous intracerebral hemorrhage (ICH) is controversial. Recent reports suggest that contrast extravasations on CT angiography (CTA) might serve as a crucial predictor of hematoma expansion and mortality. The purpose of this study was aimed at investigating the efficacy of surgical treatment in patients with spot sign positive ICH. Methods : We used our institutional medical data search system to identify all adult patients who admitted for treatment of ICH between January 1, 2007 and January 31, 2012. Patients were classified two groups into a surgical group (n=27) and a conservative treatment group (n=28). Admission criteria were the following: age 20-79 years, spontaneous supratentorial ICH, Glasgow Coma Score Ranging from 9 to 14, ICH volume ${\geq}20mL$, and treatment within 24 hours. Results : Fifty-five patients were analyzed. There was no significant difference in the ICU stay between the conservative treatment group ($7.36{\pm}3.66days$) and the surgical treatment group ($6.93{\pm}2.20days$; p=0.950). There was a significant difference in the in-hospital stay between the conservative treatment group ($13.93{\pm}8.87days$) and the surgical treatment group ($20.33{\pm}6.37days$; p=0.001). Overall mortality at day 90 after ICH was 36.4%; this included 16 of 28 patients (57.1%) in the conservative group and 4 of 27 patients (14.8%) in the surgical group. In univariate analysis, there was a positive effect of the surgical treatment in reducing mortality at 90 days (p=0.002), Glasgow Outcome Scale (GOS) at 90-day (p=0.006), and modified Rankin Scale (mRS) at 90-day (p=0.023). In multivariate logistic analysis, there was a significant difference in mortality (odds ratio, 0.211; 95% confidence interval, 0.049-0.906; p=0.036) between the groups at 90-day follow-up. However, there was no significant difference in GOS (odds ratio, 0.371; 95% confidence interval, 0.031-4.446; p=0.434) and mRS (odds ratio, 1.041; 95% confidence interval, 0.086-12.637; p=0.975) between the groups at 90-day follow-up. Conclusion : In this study of surgical treatment of supratentorial ICH in patients with spot sign positive in CTA was associated with less mortality despite of long duration of in-hospital stay. We failed to show that clinical outcome benefit of surgical treatment compared with conservative treatment in patients with spot sign positive ICH.

복압성요실금 환자에서 Kontinence HMT2000을 이용한 바이오피드백과 전기자극치료의 효과 (The Efficacy of Biofeedback and Electrical Stimulation by Kontinence HMT2000 in the Treatment of Stress Urinary Incontinence Patients)

  • 배연경;이대형;박성철;진성희;고민환;이태형
    • Journal of Yeungnam Medical Science
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    • 제20권1호
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    • pp.36-44
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    • 2003
  • Background: To evaluate the efficacy of EMG biofeedback and pelvic floor electrical stimulation in the stress urinary incontinence patients by Kontinence HMT2000. Materials and Methods: A group of 14 patients with stress urinary incontinence were treated with combined biofeedback and intravaginal electrical stimulation during 12 sessions from 2 weeks to 6 weeks. Results: At immediate post treatment, subjective cure rate was 28% and improvement rate was 57% and failure rate was 15%. Thus the overall success rate for this treatment was 85%. The result of 3 months after treatment showed cure rate 14% and improvement rate was 43%. Intravaginal pressure increased by an average of 11.9 cmH2O. Increased vaginal pressure was found in 93% of the patients and more than 50% increment of intravaginal pressure was 71%. Conclusions: Combined biofeedback and pelvic floor electrical stimulation by use of Kontinence HMT2000 is effective for the patients who have good compliance, relative low degree stress urinary incontinence. In order to attain good results, a well structured program that teaches specific muscle exercise and the patients should be followed by regular interval reinforcement treatment.

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두경부악성종양(頭頸部惡性腫瘍)의 방사선치료계획(放射線治療計劃)에 있어서 전산화단층촬영(電算花斷層撮影)의 이용(利用)에 관(關)한 연구(硏究) (Efficacy of CT-aided Radiotherapy Planning of Head and Neck Tumor)

  • 조철구;고경환;장기현;박찬일
    • Radiation Oncology Journal
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    • 제1권1호
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    • pp.47-53
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    • 1983
  • CT scans obtained on 15 patients of head and neck malignant tumors were evaluated for their utility in ratiotherapy treatment planning. To evaluate the advantage of incorporating CT scans in radiotherapy treatment planning of head and neck malignant tumors, the dose distributions of treatment plan with and without CT scan were compared in 15 patients. And then the dose distributions of the first and second treatment plan were compared. 1. Tumor extend and localization were clearly delineated on CT scan in 12 of 15 cases (80%), suggestive in 2 (13.3%), and not seen in only one (6.7%) which had been in the postoperative state. 2. Tumor coverage after CT scan was adequate in 14 of 15 cases (93.3%) and not in only one. In one case of inadequate tumor coverage the target volume lay inside the field but reached within 0.5cm of the field margin (marginal miss). 3. The volume of normal tissue irradiated was reduced after CT scan in 12 of 15 cases (80%), increased in 1 (6.7%) and not changed in 2 (13.3%). 4. We could maximize the local control of disease and minimize unnecessary morbidity by delineating the location and extent of tumor and normal tissue with CT for treatment plannings.

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