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EFFECT OF LASER IRRADIATION AND FLUORIDE APPLICATION ON REMINERALIZATION OF ERODED PRIMARY DENIAL ENAMEL (침식된 유치 법랑질에 대한 레이저 조사 및 불소도포의 재광화 효과)

  • Yang, Young-Sook;Kim, Dae-Eup;Ra, Ji-Young;Lee, Kwang-Hee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.33 no.2
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    • pp.262-268
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    • 2006
  • The purpose of this in vitro study was to evaluate the remineralizing effects of Nd : YAG laser irradiation and fluorides application on primary tooth enamel eroded by acidic drink. The materials were 30 sound primary teeth with intact smooth enamel surfaces. They were demineralized with Coca-cola at $37^{\circ}C$ for 12 hours and then irradiated by Nd: YAG laser with 6W power, $50mJ/cm^2$ energy density. and 20Hz pulse repetition. After laser irradiation, teeth were treated by three kinds of fluorides : (1) 0.05% NaF solution, (2) 1.23% APF gel and (3) 0.1% fluoride varnish. Diagnodent scores and microhardness (VHN) were measured before and after the each treatment. The results were as follows: 1. Diagnodent scores decreased to 23.51% from the initial after demineralization, and then increased to 37.37% after laser irradiation, and to 51.34% after fluoride treatment. There were significant differences between the total scores of initial, demineralization, laser irradiation and fluoride treatment (P<0.05). There was no significant difference between scores after fluoride treatment according to fluoride types. 2. Microhardness(VHN) decreased to 33.58% from the initial after demineralization and then increased to 43.99% after laser irradiation, and to 51.38% after fluoride treatment. There were significant differences between the total scores of initial, demineralization, laser irradiation and fluoride treatment (P<0.05). There was no significant difference between scores after fluoride treatment according to fluoride types.

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Recent Developments in Space Law (우주법(宇宙法)의 최근동향(最近動向))

  • Choi, June-Sun
    • The Korean Journal of Air & Space Law and Policy
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    • v.1
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    • pp.223-243
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    • 1989
  • The practical application of modern space science and technology have resulted in many actual and potential gains of mankind. These successes have conditioned and increased the need for a viable space law regime and the challenge of space has ultimately led to the formation of an international legal regime for space. Space law is no longer a primitive law. It is a modern law. Yet, in its stages of growth, it has not reached the condition of perfection. Therefore, under the existing state of thing, we could carefully say that the space law is one of the most newest fields of jurisprudence despite the fact that no one has so far defined it perfectly. However, if space law can be a true jurisprudential entity, it must be definable. In defining the space law, first of all, the grasp of it's nature iis inevitable. Although space law encompasses many tenets and facets of other legal discriplines, its principal nature is public international law, because space law affects and effects law relating intercourse among nations. Since early 1960s when mankind was first able to flight and stay in outer space, the necessity to control and administrate the space activities of human beings has growingly increased. The leading law-formulating agency to this purpose is the United Nation's ad hoc Committee on Peaceful Uses of Outer Space("COPUOS"). COPUOS gave direction to public international space law by establishing the 1963 Declaration of Legal Principles Governing the Activities of the States in the Exploration and Use of Outer Space("1963 Declaration"). The 1963 Declaration is very foundation of the five international multilateral treaties that were established successively after the 1963 Declaration. The five treaties are as follows: 1) The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space including Moon and other Celestial Bodies, 1967. 2) The Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of Objects Launched into Outer Space, 1968. 3) The Convention on International Liability for Damage Caused by Space Objects, 1972. 4) The Convention on Registration of Objects Launched into Outer Space, 1974. 5) The Agreement Governing Activities of States on the Moon and Other Celestial Bodies: Moon Treaty, 1979. The other face of space law is it's commercial aspect. Space is no longer the sole domination of governments. Many private enterprise have already moved directly or indirectly into space activities in the parts such as telecommunications and space manufacturing. Since space law as the public international law has already advanced in accordance with the developments of space science and technology, there left only a few areas untouched in this field of law. Therefore the possibility of rapid growth of space law is expected in the parts of commerical space law, as it is, at this time, in a nascent state. The resources of the space environment are also commercially both valuable and important since the resources include the tangible natural resources to be found on the moon and other celestial bodies. Other space-based resources are solar energy, geostationary and geosynchronous orbital positions, radio frequencies, area possibly suited to human habitations, all areas and materials lending themselves to scientific research and inquiry. Remote sensing, space manufacturing and space transportation services are also another potential areas in which commercial. endeavors of Mankind can be carried out. In this regard, space insurance is also one of the most important devices allowing mankind to proceed with commercial space venture. Thus, knowlege of how space insurance came into existence and what it covers is necessary to understand the legal issues peculiar to space law. As a conclusion the writer emphasized the international cooperation of all nations in space activities of mankind, because space commerce, by its nature, will give rise many legal issues of international scope and concern. Important national and world-community interests would be served over time through the acceptance of new international agreements relating to remote sencing, direct television broadcasting, the use of nuclear power sources in space, the regularization of the activities of space transportation systems. standards respecting contamination and pollution, and a practical boundary between outer space and air space. If space activity regulation does not move beyond the national level, the peaceful exploration of space for all mankind will not be realized. For the efficient regulation on private and governmental space activities, the creation of an international space agency, similar to the International Civil Aviation Organization but modified to meet the needs of space technology, will be required. But prior to creation of an international organization, it will be necessary to establish, at national level, the Office of Air and Space Bureau, which will administrate liscence liscence application process, safety review and sale of launch equipment, and will carry out launch service.

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International Space Law on the Protection of the Environment (환경보호에 관한 국제 우주법연구)

  • Kim, Han-Taek
    • The Korean Journal of Air & Space Law and Policy
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    • v.25 no.1
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    • pp.205-236
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    • 2010
  • This article deals with international space law for the environmental protection in outer space especially for space debris arising from space activities. After studying 1967 Outer Space Treaty, 1968 Rescue Agreement, 1972 Liability Convention, 1975 Registration Convention and 1979 Moon Agreement, we could find few provisions dealing with space environment in those treaties. During the earlier stages of the space age, which began in the late 1950s, the focus of international law makers was the establishment of the basic rules of space law governing the states' activities in outer space. Consequently the environmental issues and the risks that might arise from the generation of the space debris did not receive priority attention within the context of the development international space law. Although the phrases such as 'harmful contamination', 'harmful interference', 'disruption of the environment', 'adverse changes in the environment' and 'harmfully affecting' in relation to space environment were used in 1967 Outer Space Treaty and 1979 Moon Agreement, their true meaning was not definitely settled. Although 1972 Liability Convention deals with compensation, whether the space object covers space debris is unclear despite the case of Cosmos 954. In this respect international lawyers suggest the amendment of the space treaties and new space treaty covering the space environmental problems including the space debris. The resolutions, guidelines and draft convention are also studied to deal with space environment and space debris. In 1992 the General Assembly of the United Nations passed resolution 47/68 titled "Principles Relevant to the Use of Nuclear Power Sources in Outer Space" for the NPS use in outer space. The Inter-Agency Space Debris Coordination Committee; IADC) issued some guidelines for the space debris which were the basis of "the UN Space Debris Mitigation Guidelines" approved by COPUOS in its 527th meeting. In 1994 the 66th conference of ILA adopted "International Instrument on the Protection of the Environment from Damage Caused by Space Debris". Although those resolutions, guidelines and draft convention are not binding states, there are some provisions which have a fundamentally norm-creating character and softs laws.

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A Study on the increase of space debris from Chinese Anti-Satellite and breach of the Outer Space Treaty (자국위성(自國衛星)의 파괴(破壞)에 따른 우주잔해의 증가와 우주조약위반(宇宙條約違反) 여부에 관한 소고(小考) - 중국의 자국위성파괴와 관련하여 -)

  • Kim, Sun-Ihee
    • The Korean Journal of Air & Space Law and Policy
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    • v.28 no.2
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    • pp.259-294
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    • 2013
  • After its experiment involving the exploding of a satellite in space in 2007, China proudly aired news on TV and ran articles in newspapers. However, the event was internationally criticized and drew widespread attention. Many countries denounced the explosion by pointing out that it could be part of the nation's plan to expand its military power to space or that it could pose a danger to the peaceful use of space. However, there is no talk of whether the experiment that produced a huge amount of space debris could have violated an international law, namely the Outer Space Treaty. Although space garbage has been said to be a serious problem, the amount is still on the increase. If we continue to launch new space launch vehicles into orbit at this rate, we will not be able to use it anytime soon like we do today. As the commercial use of space is likely to increase, the situation will certainly get worse. The international community is fully aware of the seriousness of the problem and working together to reduce the amount of space garbage. However, despite the fact that the United States and Soviet Union's ASAT(Anti-Satellite) programs have been implemented for a long time, there have been no complaints about them in terms of military expansion or breach of the Outer Space Treaty. Also, the recent Chinese test is largely viewed to be in accordance with international law. A lot of research has been undertaken with regard to the problem of space garbage. Now people's awareness of dangers being posed has been fully raised. Under the circumstances, the dismissing of China's satellite smashing, leaving a big mess in its wake, as nothing more than an experiment, is a red flag to, if not many, at least some people. By means of this thesis, I would like to review whether the Chinese test has violated an international space law. This thesis presents an overview of the issues surrounding the event and examines the possibility of violating the Outer Space Treaty, formally the Treaty on Principle Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies. After the China test, the UN Scientific and Technical Subcommittee first adopted space debris mitigation guidelines, I'll introduce the content of the guidelines and discuss the characteristics of the guidelines and what can be done to address the issue.

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Antioxidant and Anticancer Activities of Water Extracts from Ceramium kondoi (비단풀 물 추출물의 항산화력 및 항암활성)

  • An, Deok-Ho;Cho, Seug-Ja;Jung, Eun-Sil;Lee, Hyun-Jin;Hwang, Ji-Hwan;Park, Eun-Ju;Park, Hae-Ryong;Lee, Seung-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.10
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    • pp.1304-1308
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    • 2006
  • The present study describes the preliminary evaluation of the antioxidant activity and the cytotoxic effect of Ceramium kondoi. The antioxidant activities and cytotoxic effect of the water extracts were evaluated by total phenolic contents (TPC), DPPH radical scavenging activity (RSA), reducing power (RP), comet assay, and MTT reduction assay. TPC, DPPH RSA, and RP of the extract at the concentration of $1,000{\mu}g/mL$ was $659.2{\mu}M$, 86.0%, and 1.084, respectively, and those were concentration dependent. The $200{\mu}M\;H_2O_2-induced$DNA damage was inhibited by C. kondoi water extract in a dose dependent manner in human leukocytes. The inhibition was by 62.3, 39.8, 24.8% and 16.4% at the concentration of 5, 10, $25{\mu}g/mL$ and $50{\mu}g/mL$, respectively. Cytotoxic activity on HT-29 cells and MCF-7 cells of the C. kondoi water extract at the concentration of $10{\mu}g/mL$ was 49% and 60%, respectively. These results strongly support the possibility of C. kondoi as a source of natural functional materials.

Influence for a state of nutrition reached over Hb formation (영양상태(營養狀態)가 Hb 형성(形成)에 미치는 영향(影響))

  • Lee, Geum-Yeong;Jeon, Kwan-Bae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.4 no.1
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    • pp.13-17
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    • 1975
  • 1. A nursery school principal must think over physical stamina and health of his children, and he must make an epoch making changes to nutrition control. I think that authorities concerned must give weight to quality before quantity to manage the nursery school. If the nursery school principal who has aid received from abroad and his native country must manage the nursery school rationally. It is expected that, though the nutrition level is below the level of sports middle school children, it is above the common level of home children. 2. I fear that the calories which the pupils of sports middle school assimilate a day on the average is apt to be more calories as compared with other pupils of their age(weight). This is also true for their level of activity. It is required that the nutritionist must recheck the quantity of the calorie provision. 3. I took no thought about infection with parasites in this thesis. It is because that the pupils of sports middle school have much Hb (hemoglobin), because they have had meals with a settled menu for a year or two. So, that it is expected that it is caused only by the nutritious foods regardless of parasites and that they have little Hb(hemoglobin). Besides though they are little pupils, because they have much Hb. Of taking the level with upper life classes of the the Ewha Girls University students, it will be more reliable. Therefore as we maintain the states of health of the common home children and nursery school children normally, to increase the national power, the managers of nursery schools or the heads of families must pay attention to the control of nutrition, and authorities concerned must pay attention to the control of nutrition, and authorities concerned must take the trouble much more to the management of nursery school.1. We have been undertaking the occupations of the family plannings for more ten years. But we have still failed to realize the anticipated result in the farm villages. Though it is not in this district, I think that we must make efforts in these occupations urgently, and control increases in population, decrease the consumptions of food and salt, and contribute to the increasing of the general income. 2. There is a tendency to take a little more salted foods in the cities than in the farm villages. But we are apt to take more salt in quantity(20g) to be taken in a day both in the cities and in the farm villages than it is necessary to us. So it is required that we must grope for a means of increasing of the general income as early as possible, and that we must improve our diet to be got rid of dietary life in importance. And so we have to study throughly the side effect caused due to too much salt to be taken in, if it is discovered, we must spour on a means of sweep of it.

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Psychological Make-up of Korean Green Consumerism: A Path Model Analysis (한국록색소비심리구성(韩国绿色消费心理构成):일개로경분석모형(一个路径分析模型))

  • Kim, Joo-Ho;Kim, Yeon-Shin
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.3
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    • pp.249-261
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    • 2010
  • As consumers' concern for the environment has continued to increase, many firms have actively engaged in environmental marketing to achieve their objectives. However, consumers' high concerns about the environment are not always reflected in their purchasing behavior. This indicates the need for an in-depth understanding of the development of green consumption within the individual's belief system. In consideration of psychological approaches, a large body of research has examined the factors underlying ecologically conscious "green" consumer behavior and the interrelationships of these factors. However, most previous studies have concentrated on Western countries. Using a sample of Korean consumers, this study attempts to understand the basis of Korean green consumerism and find universal values that are cross-culturally important in guiding consumers' environmental attitudes and behaviors. To this end, this study relates Schwartz's 10 universal values (Schwartz 1992) to environmental behaviors in a hierarchical model of value-attitude-behavior. With reference to the value-attitude-behavior framework, the conceptual model developed for the study explains what motivations can be manifested in Korean consumers' environmental attitudes, and subsequently how the attitudes affect their green choices. Using the pattern of relationships among values that can be related to environmentalism, the first hypothesis holds that there would be particular relationships between motivational value types and environmental attitudes. Hypothesis 2 assumes that environmental attitudes predict environmental behaviors. On the basis of the claim that favorable attitudes toward the environment may be expressed in many different behaviors, the assumption is that consumers' favorable attitudes toward the environment would be linked to a variety of environmental behaviors because people with high environmental attitudes can be more interested in and knowledgeable about environmental actions. Consistent with H2, H3 hypothesizes that there would be a positive relationship between different types of environmental behavior. A total of 564 university students participated in the study. The sample included 308 men, 254 women, and two participants who did not indicate their gender. The average age of the participants was 22.5 years, with a range of 19 to 39. Regarding majors, special efforts were made to draw the participants from different departments of the university. Data were collected by a survey administered via self-completion questionnaires., which assessed the participants' value priorities, environmental attitudes, and behaviors. Path analysis conducted to test the proposed model found the overall fit to be ${\chi}^2$=72.01 (p=0.00), GFI=0.983, CFI=0.982, NFI=0.970, RMR=0.070, and REMSEA=0.050. Thus, most of the fit measures indicated a good fit of the model with the data, and a hierarchical relationship from values to environmental attitudes to environmental non-purchasing behavior to environmental purchasing behavior was confirmed. An assessment of all the predicted paths by path coefficients led to several major hypothesized effects being confirmed. Out of the ten value types, universalism and power were significantly but conversely related to environmental attitudes. In line with the other studies, these findings confirm that environmental attitudes are an important factor in leading to a variety of green behaviors. Finally, significant relationships were found between environmental purchasing and non-purchasing behaviors. The path analysis supported the idea that universalism values provide a motivation for Korean consumers' greenness and indirectly promote environmental acts through favorable attitudes toward the environment. Participants with high environmental attitudes were found to actively engage in diverse forms of green consumer behavior. This research provides an opportunity to examine cross-cultural differences with respect to values leading to environmentalism, and, further, to verify previous findings. The study also examined the attitude-behavior relationship with respect to three distinct types of environmental behaviors. The different strengths of paths between green attitudes and behaviors suggest that researchers should consider the specificity of behavior explained as an effort to improve the low attitude-behavior correlation. Finally, the findings here illustrate that with increased environmental concerns among people, they come to include more such behaviors in their green portfolios.

A Feasibility Study on the Use of Liner and Cover Materials Using Sewage Sludge (하수슬러지의 차수재 및 복토재로의 이용타당성에 관한 연구)

  • 유남재;김영길;박병수;정하익
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.43-71
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    • 1999
  • This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

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Analysis of User′s Satisfaction to the Small Urban Spaces by Environmental Design Pattern Language (환경디자인 패턴언어를 통해 본 도심소공간의 이용만족도 분석에 관한 연구)

  • 김광래;노재현;장동주
    • Journal of the Korean Institute of Landscape Architecture
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    • v.16 no.3
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    • pp.21-37
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    • 1989
  • Environmental design pattern of the nine Small Urban Spaces at C.B.D. in City of Seoul are surveyed and analyzed for user's satisfaction and behavior under the environmental design evaluation by using Christopher Alexander's Pattern Language. Small Urban Spaces as a part of streetscape are formed by physical factors as well as visual environment and interacting user's behavior. Therefore, user's satisfaction and behavior at the nine Urban Small Spaces were investigated under the further search for some possibilities of application of those Pattern Languages. A pattern language has a structure of a network. It is used in sequence, going through the patterns, moving always from large patterns to smaller, always from the ones which create comes simply from the observation that most of the wonderful places of the city were not blade by architects but by the people. It defines the limited number of arrangements of spaces that make sense in any given culture. And it actually gives us the power to generate these coherent arrangement of space. As a results, 'Plaza', 'Seats'and 'Aecessibility' related design Patterns are highly evaluated by Pattern Frequency, Pattern Interaction and their Composition ranks, thus reconfirm Whyte's Praise of urban Small Spaces in our inner city design environments. According to the multiple regression analysis of user's evaluation, the environmental functions related to the satisfaction were 'Plaza', 'Accessibility' and 'Paving'. According to the free response, user's prefer such visually pleasing environmental design object as 'Waterscape' and 'Setting'. In addition to, the basic needs in Urban Small Spaces are amenity facilities as bench, drinking water and shade for rest.

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A Research on Ball-Balancing Robot (볼 벨런싱 로봇에 관한 연구)

  • Kim, Ji-Tae;Kim, Dae-young;Lee, Won-Joon;Jin, Tae-Seok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.463-466
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    • 2017
  • The purpose of this paper is to develop a module capable of all-directional driving different from conventional wheeled robots, and to solve the problems of the conventional mobile robot with side driving performance degradation, It is possible to overcome the disadvantages such as an increase in the time required for the unnecessary driving. The all - direction spherical wheel drive module for driving a ball - balancing robot is required to develop a power transfer mechanism and a driving algorithm for driving the robot in all directions using three rotor casters. 3DoF (Axis) A driver with built-in forward motion algorithm is embedded in the module and a driving motor module with 3DoF (axis) for driving direction and speed is installed. The movement mechanism depends on the sum of the rotation vectors of the respective driving wheels. It is possible to create various movement directions depending on the rotation and the vector sum of two or three drive wheels. It is possible to move in different directions according to the rotation vector field of each driving wheel. When a more innovative all-round spherical wheel drive module for forward movement is developed, it can be used in the driving part of the mobile robot to improve the performance of the robot more technically, and through the forward-direction robot platform with the drive module Conventional wheeled robots can overcome the disadvantage that the continuous straightening performance is lowered due to resistance to various environments. Therefore, it is necessary to use a full-direction driving function as well as a cleaning robot and a mobile robot applicable in the Americas and Europe It will be an essential technology for guide robots, boarding robots, mobile means, etc., and will contribute to the expansion of the intelligent service robot market and future automobile market.

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