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      • KCI등재

        석영과 장석의 Zeta 전위에 있어서 금속이온의 영향

        오재현,박광원,이원해,원덕환 대한금속재료학회(대한금속학회) 1974 대한금속·재료학회지 Vol.12 No.4

        石英과 長石의 活性化에 關한 資料를 얻기 爲해서 水溶液中 Mg^(++), Cu^(++), Zn^(++)과 Al^(+++)를 添加하여 鑛粒의 Zeta 電位를 測定하였다. 그리고 이들 鑛粒의 界面電氣現象과 金屬이온들의 加水分解特性을 서로 關聯시켜 比較 檢討하여 다음과 같은 結論을 얻었다. 1. 水溶液中에 金屬이온이 存在할 때 長石의 界面電氣現象은 石英과 같다. 2. 金屬이온種의 吸着으로 因해 石英과 長石의 界面은 陽(+)으로 荷電된다. 그리고 陽으로 荷電되는 pH 範圍는 金屬이온의 種類에 따라 다르다. 3. 水溶液中에 金屬이온들이 存在하면 鑛粒의 zpc(Zero point of charge)는 두 곳의 pH에서 나타난다. 두개의 zpc 중 하나의 zpc가 나타나는 pH는 M^(II)OH^+, M^(III)(OH)^+_2 및 M^(III)(OH)^(++) 이온種의 最高濃度가 나타나는 pH와 거의 一致한다. 마그네슘 이온의 경우에는 pH 10.1에서 단하나의 zpc가 나타난다. 4. Mg(II), Cu(II), Zn(II) 및 Al(III) 이온들의 加水分解特性과 zeta 電位를 關聯시켜 볼 때 Mg^(++), Cu^(++), Zn^(++) 및 Al^(+++)은 鑛粒表面에 對해 吸着力이 弱하고, 한편 M^(II)(OH)^+, M^(III)(OH)^+_2 및 M^(III)(OH)^(++) 이온種은 吸着力이 强함을 알 수 있다. To obtain a better understanding of quartz and orthoclase activation, zeta potentials of the minerals were studied in the presence of metallic ions such as Mg^(++), Cu^(++), Zn^(++) and Al^(+++). A microelectrophoresis technique has been used to measure the zeta potential, and the results have been correlated with the hydrolysis of the metallic ions in the solution. The experimental results have led to the following conclusions. 1. Zeta potentials of orthoclase in the presence of the metallic ions show a similar behavior to those of quartz. 2. Adsorption of the metallic ions renders the zeta potential of quartz and orthoclase positive. The pH range of positive zeta potential varies with the kind of cation. 3. Zero point of charge(ZPC) of the mineral surface in the presence of metallic ions appears at two different pH of solution. One of two pH of ZPC is consistent with the pH at which M^(II)(OH)^+ and M^(III)(OH)^+_2 or M^(III)(OH)^(++) species are predominant. 4. Comparison of the zeta potential data with the hydrolysis for Mg(II), Cu(II), Zn(II) and Al(III) species suggests that Mg^(++), Cu^(++), Zn^(++) and Al^(+++) are only weakly adsorbed at the mineral surface and that M^(II)(OH)^+ and M^(III)(OH)^+_2 or M^(III)(OH)^(++) are the main metallic ionic species adsorbed.

      • KCI등재

        제주도 지하수 질산염 농도의 시·공간적 변화 특성: 장기(1993-2015) 모니터링 자료의 평가

        김호림(Ho-Rim Kim),오준섭(Junseop Oh),도현권(Hyun-Kwon Do),이경진(Kyung-Jin Lee),현익현(Ik-Hyun Hyun),오상실(Sang-Sil Oh),감상규(Sang-Kyu Kam),윤성택(Seong-Taek Yun) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

        1993년부터 2015년까지 관측된 제주도 지하수 장기모니터링 관측정(N = 4,835)에서 수집된 지하수 수질자료(N = 21,568)를 기반으로 질산성질소의 시공간적 변동 특성을 평가하였다. 제주도 지하수의 질산성질소 농도의 중앙값은 2.5 mg/L로서 다른 국가나 대륙의 조사 결과에 비해 다소 높거나 유사한 것으로 나타났다. 또한 지하수 용도, 행정구역 및 고도 별로 유의한 차이를 보였다. 특히, 산간 지역에 비해 저지대 해안가에 위치한 농업 및 주거지역에서 농도가 높음을 확인하였다. Mann-Kendall 및 Sen’s slope 분석을 활용한 질산성질소 농도의 추세 분석 결과, 하류 저지 대에 비해 중산간지역에서의 질산성질소 농도 증가 경향이 뚜렷하였다. 제주도 내 토지 피복의 시계열 변화 특성과 결부 지어 보면, 중산간지역의 오염 증가 추세는 농업지역의 확장 등 인위적 활동 증가에 기인한 결과로 판단된다. 반면,기지정된 지하수자원특별관리구역에서는 전반적으로 질산성질소 농도의 감소 경향이 나타났는데, 이는 지하수 관리 측면에서 수질관리를 위한 적극적인 정책이 유효함을 시사한다. 본 연구에서는 제주도 지하수의 질산성질소 오염관리를 위한 적정 방안을 제안한다. The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of NO 3 -N is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen’s slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

      • Catalytic oxidation of hydrogen at nanocrystalline palladium surfaces

        Oh, Chanick,Hong, Kwan Soo,Lee, SangGap,Park, Chung-hyun,Yu, Insuk IOP Pub 2006 Journal of physics, an Institute of Physics journa Vol.18 No.13

        <P>We studied hydrogen adsorption onto the oxidized nano-palladium surface using <SUP>1</SUP>H NMR. In the α phase, the incoming hydrogen molecules dissociate and form OH<SUB>ad</SUB>. We confirm that the <img SRC='http://ej.iop.org/images/0953-8984/18/13/001/cm210477ieqn1.gif' ALIGN='MIDDLE' ALT='\mathrm {OH_{ad}} \rightarrow \mathrm {H_2O}(\uparrow) '/> transformation occurs during the α–β phase transition by observing a decrease in OH<SUB>ad</SUB> resonance intensity.</P>

      • SCIESCOPUSKCI등재
      • SCIESCOPUSKCI등재
      • 노인의 영적 간호요구

        최미혜,김경희,김귀옥,김기숙,김수강,김정신,김춘숙,노흥진,박지연,성혜연,오명선,이선희,이원옥,이윤영,이현수,장명재,차혜경,채정선,홍상희 중앙대학교 의과대학 간호학과 간호과학연구소 2001 중앙간호논문집 Vol.5 No.1

        This study was designed to exam the aged's needs for spiritual nursing care. The purpose was to serve as a basis for the development of spiritual nursing practice. The major findings are as follows : 1. The degree of needs for spiritual nursing care as area was that needs of love and relationship mean 22.0, needs of meaning and object mean 28.2, needs of forgiving mean 13.5. Total needs for spiritual nursing care mean 63.7, which was on the upper middle level. The needs of meaning and object was rated highest. 2. Among the general characteristics of the subjects, needs of love and relatiohship wasn't significanlty different. 3. Among the general characteristics of the subjects, needs of meaning and object was significantly different according to two factors : age(F=7.260, p=0.001), religion(F=5.275, p=0.001). Higher needs of meaning and object was possessed by the older than the younger, by the one who have religion than the other. 4. Among the general characteristics of the subjects, four factors made a significantly difference to needs of forgiving : sex(t=-2.851, p=0.006), age(F=8.201, p=0.001), religion(F=6.928, p=0.000), disease(t=2.327, p=0.024). Higher needs of forgiving was possessed by man than woman, by the older than the younger, by the one who have religion than the other, by the one who have disease than the other.

      • 주의력 결핍·과잉행동 장애 아동에 대한 이론적 고찰

        이옥형,신현오 誠信女子大學校 2001 硏究論文集 Vol.37 No.-

        Attention Deficit Hyperactivity Disorder(ADHD)is one of the most frequently diagnosed behavior problem in the children.The prevalence of this disorder has been estimated between 3 and 5%. The primary symptoms of ADHD is inattention, implusiveness and hyperactivity.Associated problems is learning disabilities, low academic performance,inappropriate adaptive functioning,deficient rule-governed behavior, and probiems with self-regulation of emotion. A varity of etiologies have been proposed for ADHD.The first major factor is neurological one.second is genetic factor.third is interaction with circumstance. At present,the primary characteristics of ADHD and dignostic criteria officially developed for clinical use are set fourth edition of the Diagnostic and Statistical Manual of Mental Disorders(DSM-Ⅳ;American Psychiatric Association,1994). The treatments of ADHD children id stimulant medication therapy, behaviortherapy,cognitive-behavioral therapy and counseling. But ADHD children have emotional problems,for example low self-concept,aggression,anger etc. So It need to cure ADHD childerns emotional problems and to develop new treat model based emotional-behavioral therapy.

      • 레일리 페이딩 환경에서 부분 SSPIC 다중 사용자 검파 기법을 적용한 DS-CDMA시스템의 성능분석

        이현재,오창헌 한국기술교육대학교 2000 論文集 Vol.7 No.1

        The performance of a successive concatenated cancellation scheme, partial SSPIC (Successive Serial Parallel Interference Cancellation) for code-division multiple-access (CDMA) uplink transmission in cellular mobile radio is analyzed. Modified partial serial and parallel cancellation stages are employed. The partial serial cancellation stage is used to shorten interference cancellation delay and the parallel cancellation stage is used to enhance system performance. Performance is analyzed in AWGN and flat Rayleigh fading asynchronous channels with both perfect and imperfect channel estimation. We have observed that the partial SSPIC multiuser detector can shorten effectively detection delay at SIC stage and maintain similar performance with SICPIC multiuser detector in both AWGN and flat Rayleigh fading channels. Therefore, proposed partial SSPIC multiuser detector can effectively improve the system performance without excessive detection delay time.

      • 齒科嬌正用線材의 物理的 性質에 미치는 熱處理의 影響

        李基大,權五源,成材鉉 慶北大學校 齒科大學 1985 慶北齒大論文集 Vol.2 No.1

        The physical properties of .016" orthodontic wires by heat treatment were studied in tension, bending, hardness and microstructures. The wires were tested in the as-manufactured and heat-treated conditions. The results were as follows: Ultimate tensile strength and yield strength were slightly increased by heat treatment, but Elgiloy was the most effective by geat treatment. The strength of Elgiloy showed the highest value after heat treatment above 6 minutes at 500, 600℃. Also, bending fluxure modulus of elasticity were progressively increased by heat treatment. the hardness number of Australian of as-manufactured wires showed the highest value, and Elgiloy showed the highest value by heat treatment. Microstructure of as-manufactured wires showed fibrous interlocking grains, and a coarse grains after heat treatment and an austenite structure after solution heat treatment.

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