• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.177-189
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• 2009

Iron (oxyhydr)oxides commonly form as secondary minerals of high reactivity and large surface area resulting from alteration and weathering of primary minerals, and they are efficient sorbents for inorganic and organic contaminants. Accordingly, they have a great potential in industrial applications and are also of substantial interest in environmental sciences. Goethite (${\alpha}$-FeOOH) is one of the most ubiquitous and stable forms of iron (oxyhydr)oxides in terrestrial soils, sediments, and ore deposits, as well as a common weathering product in rocks of all types. This study focused on adsorption reaction as a main mechanism in scavenging arsenic using goethite. Goethite was synthesized in the laboratory to get high purity, and a variety of mineralogical and physicochemical features of goethite were measured and related to adsorption characteristics of arsenic. To compare differences in adsorption reactions between arsenic species, in addition, a variety of experiments to acquire adsorption isotherm, adsorption edges, and adsorption kinetics were accomplished. The point of zero charge (PZC) of the laboratory-synthesized goethite was measured to be 7.6, which value seems to be relatively higher, compared to those of other iron (oxyhydr)oxides. Its specific surface area appeared to be $29.2\;m^2/g$ and it is relatively smaller than those of other (oxyhydr)oxides. As a result, it was speculated that goethite shows a smaller adsorption capacity. It is likely that the affinity of goethite is much more larger for As(III) (arsenite) than for As(V) (arsenate), because As(III) was observed to be much more adsorbed on goethite than As(V) in equivalent pH conditions. When the adsorption of each arsenic species onto goethite was characterized in various of pH, the adsorption of As(III) was largest in neutral pH range (7.0~9.0) and decreased in both acidic and alkaline pH conditions. In the case of As(V), the adsorption appeared to be highest in the lowest pH condition, and then decreased with an increase of pH. This peculiarity of arsenic adsorption onto goethite might be caused by macroscopic electrostatic interactions due to variation in chemical speciation of arsenic and surface charge of goethite, and also it is significantly affected by change in pH. Parabolic diffusion model was adequate to effectively evaluate arsenic adsorption on goethite, and the regression results show that the kinetic constant of As(V) is larger than that of As(III).

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.425-434
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• 2008

Arsenic contamination in soil and groundwater has recently been one of the most serious environmental concerns. This arsenic contamination can be originated from natural or anthropogenic sources. It has been well known that arsenic behavior in geo-environmental is controlled by various oxides or hydroxides, such as those of iron, manganese, and aluminum, and clay minerals. Among those, particularly, iron (oxy)hydroxides are the most effective scavengers for arsenic. For this reason, this study characterized arsenic adsorption of magnetite which is a kind of iron oxide in nature. The physicochemcial features of the magnetite were investigated to evaluate adsorption of arsenite [As(III)] and arsenate [As(V)] onto magnetite. In addition to experiments on adsorption equilibria, kinetic experiments were also conducted. The point of zero charge (PZC) and specific surface area of the laboratory-synthesized magnetite used as an arsenic adsorbent were measured 6.56 and $16.6\;g/m^2$, which values seem to be relatively smaller than those of the other iron (oxy)hydroxides. From the results of equilibria experiments, arsenite was much more adsorbed onto magnetite than arsenate, indicating the affinity of arsenite on magnetite is larger than arsenate. Arsenite and arsenate showed adsorption maxima at pHs 7 and 2, respectively. In particular, adsorption of arsenate decreased with increase in pH as a result of electrical repulsion caused by anionic arsenate and negatively-charged surface of magnetite. These results indicate that the surface charge of magnetite and the chemical speciation of arsenic should be considered as the most crucial factors in controlling arsenic. The results of kinetic experiments show that arsenate was adsorbed more quickly than arsenite and adsorption of arsenic was investigated to be mostly completed within the duration of 4 hours, regardless of chemical speciation of arsenic. When the results of kinetic experiments were fitted to a variety of kinetic models proposed so far, power function and elovich model were evaluated to be the most suitable ones which can simulate adsorption kinetics of two kinds of arsenic species onto magnetite.

• The Korean Society of Law and Medicine
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• v.17 no.2
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• pp.3-28
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• 2016

While product liability has been settled as a technical term in civil law, criminal law does not commonly accept technical term for it. Not like civil law, product liability in criminal law point outs individual responsibility and disability of normative order. Meaning that causation between individual's action of violation of duty and the result of danger of legal interest or infringement of legal interest must be proved. In criminal law excluding "non-result-constituted crimes (Unternehmensdelikt)", charge of injuring, accidental infliction of injury, homicide or involuntary manslaughter is problematic in product liability. Of course, it is necessary to distinguish whether the action related to the outcome is act or ommission. Also the causal relationship between the action and the result must be proved, and the intention or negligence should be recognized. In this paper, it analyzes cases that were problematic in Korea, Germany, Spain, etc. Mainly focusing on the problems revealed in the determination of causal relationship, especially recognizing criminal liability related to products. Furthermore it is followed by the view of reviewing the cause-and-effect relationship by 2 steps, dividing natural scientific causation and the normative causal relationship. In this process, to acknowledge criminal product liability in accordance with recognizing cause-and-effect relationship, there should be general risk of specific substance causing the outcome. This only premise can be meaningful to examine the casual relationship from specific cases. As it shows in some cases and theories, it is not contradicting general law of cause and effect by determining specific causal relationship by free evaluation of evidence if a general causal relationship does not exist. Also since judge's testimony does not hold a dominant position from rule of thumb, it is possible to recognize specific causal relationship. However this paper takes position that if there is no objective and reasonably undeniable cause and effect law. If there is no objective and reasonably undeniable causal law, which is the premise for recognizing concrete causal relations, judge should sentence guilty according to "in dubio pro reo" principle. In addition, it is not allowed for the defendant to burden unproven fact by free evaluation of evidence which has an effect of shift of burden of proof.

• Journal of Technologic Dentistry
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• v.22 no.1
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• pp.179-198
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• 2000

Since dental prosthesis is made possible only when dental technicians give themselves to the study of knowledge and the acquisition of updated skills, continuing education is of great importance in that it makes up for the efforts of dental technicians. Accordingly, continuing education relates to a system designed to contribute to the enhancement of the talents of dental technicians and the dental health of the nation. Specialized knowledge and information may work as the best weapon to preserve their jbs. This is true of this modern society where no one can expecth to survive without acquiring knowledge and information constantly for work is getting more classified and more divirsifide. This paper is dedicated to take a look at the current condition of the continuing education of dental technicians and to come up with measure to make general evaluation and to improve continuing education. This research resorts to 609 questionnaires among 6433 copies save unfaithfully responded 34 copos with 6.431 dental technicians as the subjects enrolled in the Dental technician Association. The collected questionnaires consist of 365 dental technicians living in Seoul and of 244 ones, Which account for 11.8 percent of dental technicians enrolled in the association. Because dental technicians live more in local areas than Seoul, the generalization of this survey leaves something to be desired. I have come up with the following findings. 1. 6,431 dental technicians, or 36.3 percent of an total of 14,956 licensed dental technicians, were admitted as numbers of the Dental Tachnician Association as of October 31, 1999. In the '98 continuing education. 4,141 dental technicians among 4,711 dental technicians got relevant training, and in the '99 continuing education, 4,075 technicians, or 75.9 percent of 5,365 technicians got relevant training while 1,290 technicians or 24.2 percent, fail to get relevant training. 2. The survey has it that 38.1 percent of dental technicians are ignorant of the laws on continuing education, and that technicians staying in local communities(146 persons, or 61.6%) take more part in education than those living in the capital of Korea(159 persons, or 146%), and that the older they are, the more money they earn, the more carrer they have, the higher position they hold, the more part they take in education 3. According to the survey, those who have the experience of getting training more than three times account for 52 persons(16.8%) in Seoul and 47 persons(22.4%) in local districts(p<0.01). In terms of sanctions in relation to continuing education, 26 dental technicians(4.6%) say that they have ever gotten sanctions, and 533 dental technicians(95.4%) say that they haven't. And those who were absent from continuing education(72 technicians : 13.51%) didn't get any sanction. 4. In terms of the degree of understanding continuing education, local technicians(46.8% : 110 persons) have a higher understanding of continuing education than their countparts staying in Seoul(36.0% : 130). Continuing education is not the ultimate goal itself. It should be changed to motivate those who get education to be willing to take part in contunuing education, and to help dental technicians in a practical and specific way. And the branch societies should be developde to engage in more specialized and classified expert fields. Of course, the curriculum should be so selected that the conceptions of dental technicians may be reflected to the maximum extent, and the ultimate effores should be made to effect diversity in the ways of educational methods and to perfect the preparation of continuing education on the part of instructors. Regulations should be established in relation to continuing education with a veiew to enhancing the participation of continuing education and its effectiveness. The supervision of the Ministry of Health and Welfare is of great importance in this context. The regulation of continuing education is not administrative regulation, but the expression of national will to guarantee the medical service of the nation at highest level. Therefore, it is necessary that the Ministry of Health and Welfare should change their understanding of the needs for the continuing education of dental experts, and that the expertise of government employees in charge of continuing education should be expanded. It goes without saying that the government should suppory continuing education in a financial way so as to supply the person in charge of public welfare and control the quality of national medicine.

• Journal of Korean Home Economics Education Association
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• v.27 no.3
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• pp.79-97
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• 2015

Curriculum may be defined as everything students learn at school or the specific plan of a subject that students are supposed to learn. The purpose and goals of the curriculum or who is in charge of developing the curriculum may differ by country. This study aimed at comparing the mechanisms in which the Home Economics curriculum is implemented in Korea and the Unite States at different levels. Considering that Korean government now supports increased autonomy of schools, allowing them to execute curricula according to their educational environments, it is meaningful that the advantages and disadvantages of the implementation mechanisms of two countries are explored. Specifically, middle schools in a City of Kyung-gi Province in South Korea and three states(Wisconsin, Ohio, and Washington states) in the United States are examined. The curriculum documents at different levels as well as study plans used by actual teachers are compared for this purpose. In case of South Korea, the nation state is in charge of curriculum development and the curriculum document defines the educational contents to detail in order to provide standardized learning experience to students. This type of closely controlled system warrants standardized educational contents and thus allows nation-wide assessment using standardized measures. On the other hand, it is difficult to accommodate diversities among students in terms of aptitudes and learning styles, and also limits creativity enhancement or integrative approach to teaching and learning. In comparison, curriculum in the United States is rather loosely defined, and more autonomy is granted to schools and teachers. Each of these two different systems may have advantages and disadvantages of their own. The findings of this study is expected to provide implications to curriculum development as well as to the development of framework and guidelines to the curriculum implementation.

• Journal of the Mineralogical Society of Korea
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• v.25 no.4
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• pp.185-195
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• 2012

Due to the high reduction and sorption capacity as well as the large specific surface area, nanosized mackinawite (FeS) is useful in reductively transforming chlorinated organic pollutants and sequestering toxic metals and metalloids. Due to the dynamic nature in its colloid stability, however, nanosized FeS may be washed out with the groundwater flow or result in aquifer clogging via particle aggregation. Thus, these nanoparticles should be modified such as to be built into permeable reactive barriers. This study employed coating methods in efforts to facilitate the installation of permeable reactive barriers of nanosized mackinawite. In applying the methods, nanosized mackinawite was coated on non-treated silica sand (NTS) and chemically treated silica sand (CTS). For both silica sands, the maximum coating of mackinawite occurred around pH 5.4, the condition of which was governed by (1) the solubility of mackinawite and (2) the surface charge of both silica and mackinawite. Under this pH condition, the maximum coating by NTS and CTS were found to be 0.101 mmol FeS/g and 0.043 mmol FeS/g respectively, with such elevated coatings by NTS likely linked with impurities (e.g., iron oxides) on its surface. Arsenite sorption experiments were performed under anoxic conditions using uncoated silica sands and those coated with mackinawite at the optimal pH to compare their reactivity. At pH 7, the relative sorption efficiency between uncoated NTS and coated NTS changed with the initial concentration of arsenite. At the lower initial concentration, uncoated NTS showed the higher sorption efficiency, whereas at the higher concentration, coated NTS exhibited the higher sorption efficiency. This could be attributed to different sorption mechanisms as a function of arsenite concentration: the surface complexation of arsenite with the iron oxide impurity on silica sand at the low concentration and the precipitation as arsenic sulfides by reaction with mackinawite coating at the high concentration. Compared to coated NTS, coated CTS showed the lower arsenite removal at pH 7 due to its relatively lower mackinawite coating. Taken together, our results indicate that NTS is a more effective material than CTS for the coating of nanosized mackinawite.

• Korean Security Journal
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• no.53
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• pp.63-79
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• 2017

Defence Security Command is the only military intelligence and investigation agency which is in charge of safeguarding military information and investigating specific crimes such as subversion and disloyalty in military. While the presidential security provided by Defence Security Command, along with Presidential Security Service(PSS) and the police, forms one of three pillars sustaining presidential security, its works and activities have been rarely known to the public due to the military confidentiality. This study looks into some data specialized into the presidential security among works of Defense Security Command by using various resources such as biographies of key people, media reports, and public materials. It reviews the presidential security works in a historical sense that the works have developed and changed in accordance with the historical changes of Defense Security Command, which was rooted in Counter-Intelligence Corps (Teukmubudae in Korean) in 1948 and leads to the present. The study findings are as follows. First, when the Korean War broke out in 1950 and since then the South Korea was under the threat of the North Korean armed forces and left wing forces, Counter-Intelligence Corps(Bangcheopdudae in Korean) took the lead in presidential security more than the police who was in charge of it. Secondly, even after the Presidential Security Office has founded in 1963, the role of the military on presidential security has been extended by changing its titles from Counter-Intelligence Corps to Army Security corps to Armed Forces Security Command. It has developed their provision of presidential security based on the experience at the president Rhee regime when they could successfully guard the president Rhee and the important government members. Third, since the re-establishment into Defence Security Command in 1990, it has added more security services and strengthened its legal basis. With the excellent expertise, it played a pivotal role in the G20 and other state-level events. After the establishment of the Moon Jaeinin government, its function has been reduced or abolished by the National Defense Reform Act. However, the presidential security field has been strengthening by improving security capabilities through reinforcing the organization. This strengthening of the security capacity is not only effective in coping with the current confrontation situation with the hostile North Korean regime, but also is important and necessary in conducting constant monitoring of the military movement and security-threat factors within military during the national security events.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.406-413
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• 2012

Effect of three additives, chitosan, ferric chloride, and MPE50 on membrane fouling reduction was studied. They were introduced with various dosing rate into activated sludge, and changes in filtration resistance measured by the batch cell filtration test were evaluated. Both the filtration resistance and the specific cake resistance were minimized at 20 mg/g-MLSS with chitosan, 70 mg/g-MLSS with ferric chloride, and 20 mg/g-MLSS with MPE50 addition, respectively. Introduction of the additives into the activated sludge resulted in reduction of not only cake resistance, but also fouling resistance. However, the chitosan addition to three different activated sludge resulted in three different optimal dose of 10, 20, 30 mg/g-MLSS, respectively. This implies that the optimal dose is dependent on sludge characteristics rather than a constant value. Overdose above the optimal dosage always aggravated filterability in all cases. Zeta potential of sludge flocs, relative hydrophobicity, floc size distribution, soluble EPS concentration and supernatant turbidity were measured in order to analyze fouling reduction mechanism. Nearly neutral surface charge along with the largest particle size was observed at the optimal dose. This could be explained by particle destabilization and restabilization mechanism as positively charged additives were injected into sludge flocs of negative surface charge. Both soluble EPS concentration and supernatant turbidity also showed the lowest value at the optimal dose. These foulants are believed to be coagulated and entrapped in sludge flocs during flocculation. Chitosan and MPE50 which are cationic polymeric substances showed higher reduction in both soluble EPS and fine particles comparing with ferric chloride.

• Journal of the military operations research society of Korea
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• v.34 no.3
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• pp.31-40
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• 2008

The aircraft manufacturing industry is a profitable business and has the potential to be an important export business. Our trade deficit needs to be improved in aircraft manufacturing part. Our national aircraft industry, which has been recognized for its quality in many domestic and international Air Shows, has developed the T/A-50 aircraft from the origins of the KT-1. With the ongoing development of the next generation fighter planes and helicopters, business for the next generation domestic air cargo has bright prospects. Judging by the history of the overseas air force dispatch during the Vietnam, Gulf, and Iraqi wars whose main mission was air transportation, there will be many opportunities to show the excellence of Korean air cargo in the future. The purpose of this study is to discover the optimal scale of air cargo development using the AHP method. The authors evaluated the scale of air cargo in size and capacity based on the following 5 standards used Korean developing airliner: usability, economics, technology, safety, and environmental friendliness. Then, the authors modified specific standards suitable for air cargo based on literature review Decision-making groups were chosen for suitability of expert staff in charge because they could represent for leading opinions in this specialized area especially as in practical aspects. The participants of the evaluation were pilots, transportation officers and management staff in the KAI who have experienced over 5years.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.64-69
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• 1998

New thirty derivatives of 5,6-dihydro-2-trifluoromethyl-1,4-oxathiin carboxanilide as substrate(S) were synthesized and their fungicidal activities in vivo against rice sheath blight(Rhizoctonia solani) and wheat leaf rust(Puccinia recondita) were examined. The structure activity relationships(SAR) between the activities($pI_{50}$) and a physicochemical parameters of substituents(X) at the phenylcarbamoyl group were analyzed using the adaptive regression analysis method. The 3-methoxy, 11, 3-isopropyloxy, 13 and 3-isopropyl substituent, 25 as X on the phenylcarbamoyl group exhibited the most highest fungicidal activity against the two fungi. The fungicidal potency of the (S) against Puccinia recondita was higher than Rhizoctonia solani. In case of Rhizoctonia solani, the molecular hydrophobicity(${\pi}>0$) and resonance effect(R<0) by meta-alkyl substitutents with electron donating were important factors in determining fungicidal activity. And the HOMO energy(HOMO>0), ABSQ, sum of absolute values of the atomic charges on each atom and specific polarizability(Sp.Pol<0) of (S) were significantly influential towards fungicidal activity against Puccinia recondita.. The interaction between (S) and receptor agonist from the based on SAR studies proceeds through charge-control reaction, and conditions to show higher activity has been also discussed.