• Title/Summary/Keyword: Control of separation

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The Effect of Temporary Cement Cleaning Methods on the Retentive Strength of Cementation Type Implant Prostheses (임시 시멘트 제거방법이 시멘트 유지형 임플란트 보철물의 유지력에 미치는 영향)

  • Shin, Hwang-Kyu;Song, Young-Gyun;Shin, Soo-Yeon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.2
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    • pp.125-140
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    • 2011
  • The remnant of temporary cement on the intaglio surface of cast restoration may have a negative effect on the retentive strength of permanent cement. This study was to evaluate the effect of temporary cement cleaning methods on the retentive strength of cementation type implant prostheses. Prefabricated implant abutments - height 5.5mm, diameter 4.5mm, 6 degree axial wall taper with chamfer margins were used. Forty copings-abutment specimens were divided into four groups(each n=10) according to the cleaning methods for temporary cement(Temp-$Bond^{(R)}$) as follows : no temporary cementation(the control group), orange solvent, ultrasonic cleaning, air borne-particle abrasion. After the application of temporary cement and the separation, the cleaning procedure was performed according to the protocol of each group. The specimens were cemented with $Premier^{(R)}$ Implant $Cement^{TM}$. After the permanent cementation, the specimens were subjected to thermocycling and pulled out from the specimens with a universal testing machine at a cross-head speed of 0.5mm/min. After the retentive strength test, all the specimens were cleaned using ultrasonic cleaning, abraded with air borne-particles, and steam-cleaned. Likewise, the specimens were temporarily cemented(Temp-$Bond^{(R)}$ NE), cleaned according to the protocol of each group, cemented with $Premier^{(R)}$ Implant $Cement^{TM}$ and subjected to thermocycling and measurement of their retentive strength. The mean of group with orange solvent were significantly lower than those of other groups(p<0.05). There was no significance between group with ultrasonic cleaning and group with air borne-particle abrasion. Group with ultrasonic cleaning and group with air-particle abrasion were no significance at control group. There was no significance between group cemented with Temp-$Bond^{(R)}$ and group cemented with Temp-$Bond^{(R)}$ NE. Within the limitation of this study, it can be concluded that the temporary cement cleaning method with only orange solvent may have a negative effect on the retentive strength of permanent cement. Ultrasonic cleaning and air borne-particle abrasion methods are recommended for the temporary cement cleaning method on cementation type implant prostheses.

Seedling Emergence and Growth Affected by Priming and $GA_3$ Treatments to Three Campanulan Plant Seeds (Priming과 $GA_3$ 처리에 따른 도라지, 더덕 및 만삼의 출아(出芽)와 생장(生長))

  • Kang, Jin-Ho;Kim, Dong-Il;Kang, Shin-Yun;Shim, Young-Do;Han, Kyung-Soo
    • Korean Journal of Medicinal Crop Science
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    • v.5 no.4
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    • pp.307-313
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    • 1997
  • Seed germination test done in laboratory does not coincide with field emergence in general. The experiments were carried out to examine the effect of priming and $GA_3$, treatment to seeds of Platycodon grandiflorum; Codonopsis lanceolata and C. pilosula on lapsed time to first seedling emergence, seedling emergence, morphological characters and growth and the cause of poor emergence of C. pilosula. No-treatment as Control (water), priming or $GA_3$ treatment was done with only distilled water for 2 days, $CA(NO_3)_2$ 150 mM for 2 days or $GA_3$ 0.1 mM for 3 days, respectively. Seedling emergence rate was counted every 2 days but morphological characters and dry weight of shoot and root were measured on 38 days after sowing. Their internal seed structures were examined with Scanning Electron Microscope. C. pilosula had poorer seedling emergence rate than P grandiflorum and C. lanceolata showing nearly same rate: Compared to the other treatment (s) P. grandiflorum displayed higher rate in priming and $GA_3$, treatments but C. lanceolata or C. pilosula did the greatest rate in only $GA_3$ or priming treatment, respectively. $GA_3$ treatment to seeds of P. grandiflorum and C. lanceolata shortened the lapsed time to seedling emergence in comparison with Control, 2-days water imbibition before sowing. In all the species plant height and number of leaves per seedling became shorter and less in priming treatment than the other treatments except plant height of C. Pilosula while their hypocotyl length was nearly same in all treatments. Although priming treatment had nearly similar effect to morphological characters, $GA_3$ treatment forced greater shoot, root and aftermath total dry weight per seedling. Poor seedling emergence of C. pilosula was caused by its seed defect like cleavage or lack of embryo, poor development of embryo and endosperm or their separation.

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Effects of Melatonin on Preventing Postoperative Intraperitoneal Adhesion Formation in Rats (Rat에서 술후 복강 유착방지에 대한 melatonin의 효과)

  • Lee, Seung-Chan;Kim, Jung-Eun;Kwon, Young-Sam;Jang, Kwang-Ho
    • Journal of Veterinary Clinics
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    • v.23 no.3
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    • pp.230-235
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    • 2006
  • This study was performed in rats to find the minimum dose of melatonin that can effectively prevent the formation of postoperative intraperitoneal adhesions. Forty-two Sprague Dawley male rats were divided into six groups consisting of 7 rats, respectively. After celiotomy, five abrasions of $0.5{\times}1cm$ area were made on the antimesenteric serosal surface of the colon with a scalpel blade. The abdominal cavity was filled with 1 ml of solution containing 1 mg/kg(Mel 1), 3 mg/kg(Mel 3), 10 mg/kg(Mel 10), 30 mg/kg(Mel 30) and 5% ethanol solution(sham) through the catheter, using a sterile syringe before abdominal closure. Control group was given no adjuvant. The locations and values of adhesion were assessed through the second operation on the 14th day after the first operation. The adhesions were located on serosa to mesentery(54 of 210, 25.7%), serosa to serosa(44 of 210, 21%), serosa to omentum (12 of 210, 5.7%) and serosa to parietal peritoneum(0 of 210, 0%). The incidences of adhesion in Control, Sham, Mel 1, Mel 3, Mel 10 and Mel 30 were 68.6%, 91.4%, 57.1%, 60.1%, 17.1% and 20%, respectively. The values of adhesion separation in Mel 10 and Mel 30 group were lower than those in other groups. However, there was no significant(p<0.05) between Mel 10 and Mel 30 group. This study showed that 10 mg/kg of melatonin were effective in reducing the intraperitoneal adhesion.

Periodontal Management strategies for the future in Korea (2000년대 치주처치의 전략)

  • Chung, Hyun-Ju;Son, Sung-Hee
    • Journal of Periodontal and Implant Science
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    • v.27 no.3
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    • pp.533-547
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    • 1997
  • In periodontics, much progress was made in the understanding of periodontal disease from 1960s to 1980s and in prevention and management of periodontal disease since the end of 1980s. This presentation will discuss about the prevalence of periodontal disease, treatment need, and provision of periodontal treatment in Korea, and how we could manage the periodontal disease efficiently in the future. According to an epidemiological study in Korea, periodontal disease(including gingivitis) was present in 82% of general population and periodontitis in 30-40% in adult population over 30y and juvenile periodontitis in 0.1% of adolescents. If we consider that at least 17% of these patients may have recurrent or refractory forms, there is obviously an abundance of disease that needs treatment, As a result of increase in life expectancy, senile population over 65 y will be increased from 6% in 1996 to 6.9% in 2000, and tooth retention rate and periodontal treatment need are expected to increase. Periodontists need all the help they can get from the general dentists to control periodontal disease. As for provision, postgraduate course in periodontics started in 1957 in Korea and produced over 700 specialized dentists in periodontics. One report indicated that the periodontists as well as general practitioners did periodontal therapy on only a few periodontal patients, because of specific control by current medical insurance system in Korea. Comprehensive periodontal examination is rarely done in local dental clinic. Therefore, enhancement of periodontal care in medical insurance system and education of simplified periodontal examination such as Periodontal Screening & Recording will make dentists diagnose and manage the management of adult patients is based on the recognition that there are multiple diseases, including gingivitis, chronic adlt periodontitis, and other more aggressive forms of periodontitis, and requires the earliest possible recognition of these three disease categories. In this presentation, we discuss practical approach using PSR to diagnose, manage and refer the patients, to facilitate the separation of the simple from the complex and the predictable from the unpredictable form of periodontal diseases and to integrate diagnostic and therapeutic techniques into private practice today.

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CHILDHOOD TRAUMA:RESILIENCE AND RISK FACTORS ON DEVELOPMENTAL TRAJECTORY (소아기 외상 : 발달경로에 따른 보호 및 위험인자)

  • Kim, Young-Shin
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.13 no.1
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    • pp.15-23
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    • 2002
  • Knowledge regarding the resilience factors and risk factors of the childhood trauma on the developental trajectory is in its infancy due to the lack of prospective follow-up studies in the childhood trauma and limited understanding of the complex reciprocal interactions between childhood trauma, develop-ent and various aspects of children's environment. These difficulties in the conceptual framework and research methods in the childhood trauma are partly reflected in the inconsistencies, even controversies, of the results in the childhood trauma researches. Despite these difficulties, common aspects of the risk factors and resilience of the childhood trauma on the development can be identified from the previous studies. The resilience to the negative outcome on the development by childhood trauma includes:sex female before puberty, male after puberty or infancy), high socioeconomic status, no organic problem, easy temperament, no previous experience with early loss or separation, younger age at the trauma, better problem solving capacity, high self-esteem, internal locus of control, high coping skills, ability to identify interpersonal relationships, ability to play, sense of humor, having capable parents, having a warm relaionship with at least one of the parents, high education and participating in the organized religious activities. These commonalities of the results suggest that risk and resilient factors of the childhood trauma are interdependent, each factor has multiplicity in the impacts on the children's development according to the developmental stage of the child, family and children's other environment, trauma and stressor have diverse effects according to their intensity and risk and resilience factors could have synergistic or antagonistic effects to each other. To develop comprehensive understanding on the relationship between childhood trauma and developmental psychopathology, risk and resilience factors and to develop effective and efficient prevention and intervention, research on the effect of the stress on the neurodevelopment, on the individual differences of the response to the trauma including genetic factors and constitution, and on the brain plasticity should be accompanied in the future.

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Effect of TGF-$\beta$1 and IGF-I on Bovine In Vitro Maturation and Embryo Culture (TGF-$\beta$1와 IGF-I이 소 난포란의 체외성숙 및 체외수정란의 배양에 미치는 영향)

  • 서태광
    • Korean Journal of Animal Reproduction
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    • v.20 no.2
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    • pp.111-117
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    • 1996
  • This experiment was designed to evaluate the effect of transforming growth factor-$\beta$ (TGF-$\beta$) and insulin-like growth factor-I (IGF-I) in bovine oocyte maturation in the presence or absence of serum on subsequent fertilization and embryo development. In addition, various concent rations of these growth factors were evaluated for the ability to promote development of eight-cell stage embryos to the blastocyst stage. Cumulus-oocyte complexes were recovered from 2 to 6 mm follicles obtained from slaughterhouse ovaries and cultured at 38.5$^{\circ}C$ for 24 hours in TCM-199 (HEPES Modification) with or with out 20 % fetal bovine serum (FBS) to which the following growth factors were added TGF$\beta$ IGF-l or TGF $\beta$ + IGF-I, all at 10 ng/ml each. The matured oocytes were fertilized in IVF-TL medium with frozen-thawed semen at a concentration of 1 ${\times}$ 10$^6$ cells/ml of fertilization medium following Percoll separation. After 24 hours of sperm-egg incubation, the embryos were transferred to CZB medium without glucose for 48 hours and then cultured in TCM-199 with 20% fetal bovine serum (FBS) for 96 hours. The addition of growth factors to IVM medium in the presence of serum had no effect on cleavage and subsequent embryo devlopment to blastocyst. In the absence of serum, TGF- improved cleavage and development to blastocyst compared to control's(p<0.05) and no synergistic effeet of IGF-I + TGF-$\beta$ was observed. In the second experiment, eight-cell embryos obtained by in vitro maturation (IVM) in TCM-199 + 20% FBS without growth facrors and in vitro fertil-ization (IVF) were cultured in the in vitro cuiture (IVC) medium supplemented with 5, 10 ng/ml TGF-$\beta$ or 5, 10, 50, 100 ng/ml IGF-I. Cleavage rate and development to the blastocyst stage was observed during seven days of incubation. The supplementation of 10 ng/ml TGF-$\beta$ to lVC medium for eight-cell embryos improved development to blastocyst (p<0.05) compared to control. In conclusion, these data indicate that the supplementation of growth factors to IVM medium in the presence of serum does not influence cleavage and subsequent embryo development. However, significantly more oocytes matured in serum-free TCM-199 and eight-cell embryos cultured in lVC medium developed to blastocyst with supplementation of 10ng/ml TGF-$\beta$.

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Experimental Study on the Infiltration Loss in Plastic Greenhouses Equipped with Thermal Curtains (보온커튼을 설치한 플라스틱 온실의 틈새환기전열량 실측조사)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.24 no.2
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    • pp.100-105
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    • 2015
  • The calculation method of infiltration loss in greenhouse has different ideas in each design standard, so there is a big difference in each method according to the size of greenhouses, it is necessary to establish a more accurate method that can be applied to the domestic. In order to provide basic data for the formulation of the calculation method of greenhouse heating load, we measured the infiltration rates using the tracer gas method in plastic greenhouses equipped with various thermal curtains. And then the calculation methods of infiltration loss in greenhouses were reviewed. Infiltration rates of the multi-span and single-span greenhouses were measured in the range of $0.042{\sim}0.245h^{-1}$ and $0.056{\sim}0.336h^{-1}$ respectively, single-span greenhouses appeared to be slightly larger. Infiltration rate of the greenhouse has been shown to significantly decrease depending on the number of thermal curtain layers without separation of single-span and multi-span. As the temperature differences between indoor and outdoor increase, the infiltration rates tended to increase. In the range of low wind speed during the experiments, changes of infiltration rate according to the outdoor wind speed could not find a consistent trend. Infiltration rates for the greenhouse heating design need to present the values at the appropriate temperature difference between indoor and outdoor. The change in the infiltration rate according to the wind speed does not need to be considered because the maximum heating load is calculated at a low wind speed range. However the correction factors to increase slightly the maximum heating load including the overall heat transfer coefficient should be applied at the strong wind regions. After reviewing the calculation method of infiltration loss, a method of using the infiltration heat transfer coefficient and the greenhouse covering area was found to have a problem, a method of using the infiltration rate and the greenhouse volume was determined to be reasonable.

The Influence of Musical Activities on Social and Emotional Behavior of Infants (음악활동이 영아의 사회·정서적 행동에 미치는 영향 - 만 2세(25-36개월) 영아를 중심으로)

  • Nam, Ok Seon
    • Journal of Music and Human Behavior
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    • v.4 no.2
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    • pp.18-40
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    • 2007
  • The purpose of this study was to verify the influence of musical activities on social and emotional behavior of infants, through providing musical activities to the infants who were cared in a nursery and observing the interactions between peer group, or a therapist and an infant derived during them. The subject is 24 infants who are under 2 years of age(25~36months) at two nurseries located in Bundang area, and 13 infants among them are randomly assigned as study group and 11 infants as control group. Pretest and posttest about social and emotional behavior are performed, and ITSEA developed by Brggs-Gowan and Carter(2001) and amended by Shin Ji Yeon(2004) was used as an evaluation tool. Infants' changes of interaction behaviors during musical play were also analyzed quantitatively and qualitatively, and for the analysis, infant's social play behavior examination tool developed by Holloway and Reichhart-Erickson(1988) was adopted. Based on time sampling method, each item of this tool was evaluated. Each session was performed for 15 minutes, and 60 times of analysis about interactions per session was conducted at every 15 seconds. The analysis result was showed with a table and a graph, and described qualitatively about behavior changes. When compared social and emotional positive behavior average figures and negative behavior average figures between study group and control group, this study showed that the positive behavior figure of study group was increased and the negative behavior figure was decreased. While concentration and empathy among positive behaviors increased meaningfully, aggression, defiance, separation anxiety and rejection to new things among negative activities also decreased meaningfully. The conclusion of this study is as follows. First, interactions with peers or a therapist based on music and musical experience make an effect on strengthening positive behavior among social and emotional behavior and decreasing negative behavior. Second, music has influence on negative behaviors more than positive behaviors of an infant, and produces a good effect on sub behaviors of negative behaviors specially.

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The Study on the Contents and Satisfaction of Oriental Medicine Examination Program (한방건강검진 프로그램의 내용과 참가자들의 만족도에 관한 연구)

  • Lee Eun-Kyoung;Jahng Doo-Sub;Song Yung-Sun;Lee Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.6 no.1
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    • pp.51-95
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    • 2002
  • 1. As a point at issue of occidental medicine examination, followings have been indicated, 1) Occidental medical examination is performed by mainly test and instrument and therefore, role of doctors could be excluded and it could be diagnosed only for target disease and 2) in Korea, it could not be conducted in public medical system and therefore improvement effect of public health promotion could not be made due to increase of total medical expenses and infirmity of post management. These points are substantial limit of paradigm resided in occidental medicine and also problem caused by unique characteristics of medical system of Korea. In Korea, result of occidental medical examination show increased health risk from aged thirties and major diagnosed diseases are circulatory disease or chronic disease such as hepatic, hyperlipemic, hypertensional disease and diabetes, etc. Accounting that those chronic disease make a role as major public health risk, it is difficult that medical examination by only occidental medicine make effect on public health promotion. 2. Characteristics of oriental medicine examination could be summarized as diagnosis (information acquisition based on the facts) and demonstration (speculation based on acquired information) and in addition, quadruple diagnosis, as a medical examination method, include test as well as basic examination. Accounting on oriental medical examination, principally it is performed by independent herbalist and therefore, herbalist could acquire systemic result during first medical examination. Based on the theory of inner-outer examination, oriental medical examination has a principle of universe theory, systemic analysis of quadruple diagnosis, demonstration & reasoning. In addition, root of oriental medical examination could be found in pre-disease theory, a principal theory of oriental medicine. Pre-disease service could prove the advantage of oriental medicine in medical examination activities and therefore, it is needed that content of oriental medical examination should be actualized in current medical system. 3. In this study, oriental medical examination program, comprised of pulse-diagnosis, contrast muscular taking and medical consultation of herbalist is progressed communally with occidental medical examination. As pre-examination, questionary was given of general characteristics, health promoting life style, physical constitution and subjective symptom of musculoskeletal system. In addition, post-examination notification was given to subjects about health promoting control, physical constitution regimen and management of musculoskeletal system. During this study program, verification was conducted for input of acquired information and difference of each information after analysis and in addition, performed was analysis of factor influencing health promoting life style and musculoskeletal subjective symptom and evaluation of relationship of physical constitution and health promoting life study. In addition, it was verified of difference between musculoskeletal subjective symptom and result of muscle contrast picture evaluation. 4. Evaluation of oriental medical examination model is divided into 2 categories of oriental medical examination-consultation and result evaluation -post management. Oriental medical examination-consultation demands establishment of examination system, standardization of examination and establishment of examination form and in addition, it should be admitted as enlarged examination assists systemic quadruple diagnosis of herbalist not a key of oriental medical examination. In addition, information acquisition for research purpose should be performed according to the systemic research plan based on the separation of questionary for examination purpose and research purpose. For evaluation of the result, it was concluded that needed are result evaluation meets oriental medical system and post-notification system, informing health management information, based on examination result. 5. Accounting on satisfaction for oriental medical examination model, affirmative reply was much higher (66%) than negative (8.64%). Satisfaction of each area was in order of consultation of herbalist, systemic muscle contrast taking, pulse examination, post-notification and questionary fill-up and dissatisfaction was in order of post-notification, questionary fill-up, consultation of herbalist, systemic muscle contrast taking and pulse measurement. Satisfaction for collaborative examination of occidental and oriental medicine was over 60% and over 75% hope oriental examination would be included in later medical examination program. Based on this result, collaborative examination including occidental and oriental medicine could increase satisfaction of subjects for medical examination program.

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Characterization of Arsenic Immobilization in the Myungbong Mine Tailing (명봉광산의 광미 내 비소의 고정화 특성 연구)

  • Lee, Woo-Chun;Jeong, Jong-Ok;Kim, Ju-Yong;Kim, Soon-Oh
    • Economic and Environmental Geology
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    • v.43 no.2
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    • pp.137-148
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    • 2010
  • The Myoungbong mine located in Boseong-gun, Jellanamdo consists of Au-Ag bearing quartz veins which filled the fissures of Bulguksa granitic rocks of Cretaceous. The tailings obtained from the Myungbong mine were used to investigate the effects of various processes, such as oxidation of primary sulfides and formation(alteration) of secondary and/or tertiary minerals, on arsenic immobilization in tailings. This study was conducted via both mineralogical and chemical methods. Mineralogical methods used included gravity and magnetic separation, ultrasonic cleaning, and instrumental analyses(X-ray diffractometry, energy-dispersive spectroscopy, and electron probe microanalyzer) and aqua regia extraction technique for soils was applied to determine the elemental concentrations in the tailings. Iron (oxy)hydroxides formed as a result of oxidation of tailings were identified as three specific forms. The first form filled in rims and fissures of primary pyrites. The second one precipitated and coated the surfaces of gangue minerals and the final form was altered into yukonites. Initially, large amounts of acid-generating minerals, such as pyrite and arsenopyrite, might make the rapid progress of oxidation reactions, and lots of secondary minerals including iron (oxy)hydroxides and scorodite were formed. The rate of pH decrease in tailings diminished, in addition, as the exposure time of tailings to oxidation environments was prolonged and the acid-generating minerals were depleted. Rather, it is speculated that the pH of tailings increased, as the contribution of pH neutralization reactions by calcite contained in surrounding parental rocks became larger. The stability of secondary minerals, such as scorodite, were deteriorated due to the increase in pH, and finally arsenic might be leached out. Subsequently, calcimn and arsenic ions dissociated from calcites and scorodites were locally concentrated, and yukonite could be grown tertiarily. It is confirmed that this tertiary yukonite which is one of arsenate minerals and contains arsenic in high level plays a crucial role in immobilizing arsenic in tailings. In addition to immobilization of arsenic in yukonites, the results indicate that a huge amount of iron (oxy)hydroxides formed by weathering of pyrite which is one of typical primary minerals in tailings can strongly control arsenic behavior as well. Consequently, this study elucidates that through a sequence of various processes, arsenic which was leached out as a result of weathering of primary minerals, such as arsenopyrite, and/or redissolved from secondary minerals, such as scorodite, might be immobilized by various sorption reactions including adsorption, coprecipiation, and absorption.