• Title/Summary/Keyword: LED Control

Search Result 2,122, Processing Time 0.04 seconds

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
    • /
    • v.1
    • /
    • pp.223-243
    • /
    • 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.

  • PDF

A Study on the Effectiveness and Possibility of Chemistry Inquiry Programs Based on Reverse Science Principle (RSP(Reverse Science Principle)기반 화학 탐구 프로그램의 효과 및 가능성 탐색)

  • Jo, Eun-ji;Yang, Heesun;Kang, Seong-Joo
    • Journal of the Korean Chemical Society
    • /
    • v.62 no.4
    • /
    • pp.299-313
    • /
    • 2018
  • Inquiry-centered education is important in science education, but in the actual education field, scientific research is being done in a uniform manner due to realistic difficulties. In this study, we use RS (Reverse Science) as a secondary chemistry class to provide opportunities for students to engage in inquiry learning and scientific thinking through process-oriented activities. In this study, we developed and applied it to explore the effects on the scientific inquiry abilities of middle school students and checked the students' perception of it. For the application of the program, 128 students were selected from 6 classes of the 2nd grade in D district middle school, 64 from the experimental group and 64 from the comparative group. The experimental group taught RSP-based the chemistry inquiry programs and the comparative group taught instructor-led classes and verification experiments on the same topic over the seventh hour with three themes. In addition, we analyzed the results of the pre- and post-test by using the science inquiry ability test, and discussed the effects of the program based on the students' perceptions through class observation, student activity area, questionnaire and interview. As a result, the class using the program showed statistically significant changes in the science inquiry ability of secondary school students. Specifically, the experimental group was found to be significant in its prediction among the subcomponents of basic exploration ability compared to the comparative group. The differences have also been shown to be significant in terms of data translation, hypothesis setup and variable control, which are subcomponents of integrated exploration capabilities (p <. 05). In addition, students became interested in the process of creating the theory of science, and were highly interested in collaborating with their friends. It also provided students with opportunities to experience scientific thinking through process-oriented inquiry. Finally, based on the positive impact of the RSP-based chemistry inquiry program on students, we were able to identify the potential use of the program.

The Effect on the Forest Temperature by Reduced Biomass Caused by Natural Forest Thinning (천연림 간벌에 기인한 산림생물량 감소가 산림 내부 온도에 미치는 영향 연구)

  • Kang, Rae-Yeol;Hong, Suk-Hwan
    • Korean Journal of Environment and Ecology
    • /
    • v.32 no.3
    • /
    • pp.303-312
    • /
    • 2018
  • This study was conducted to investigate the relationship between the decrease of forest biomass by forest thinning and the change of temperature in the natural forest by measuring forest biomass and temperature before and after forest thinning in the Pusan National University forest where afforestation had been carried out. We intended to investigate the relationship between the forest biomass, estimated by calculating the Basal area, Crown area and Crown volume using the same formula to the same quadrat before and after forest thinning, and the forest temperature. Temperature measurement was carried out on April 20, 2016 through 28 before forest thinning, July 26, 2016 through November 4 around the time of forest thinning, and April 15, 2017 through May 8 after forest thinning. A temperature data logger was installed to point north at the height of 2.0 m above the ground in the center of the quadrat to record data every 10 minutes during the measurement periods. We used the AWS (Automatic Weather Station) data of the Dongnae-gu area located in the nearby city because it was difficult to set the control group since the whole forest was the subject to the forest thinning. The analysis of the relationship between forest biomass change and temperature showed that the change in temperature inside the forest was the greatest in the midday (12:00 - 15: 00) and was highly correlated with the Crown volume in the forest biomass. The temperature increase was much larger (average $1.91^{\circ}C$) 1 year after forest thinning than immediately after forest thinning (average $0.74^{\circ}C$). The comparison of the decrease rate of Crown volume and the increase in temperature showed that the Pitch pine community, which showed the highest decrease of Crown volume by 15.4%, recorded the highest temperature rise of $1.06^{\circ}C$ immediately after forest thinning and $2.49^{\circ}C$ 1 year after forest thinning. The Pitch pine-Korean red pine community, which showed the lowest Crown volume reduction rates with 5.0%, recorded no significant difference immediately after forest thinning but a temperature rise of $0.92^{\circ}C$ 1 year after forest thinning. The results confirmed that the decrease of forest biomass caused by forest thinning led to a rapid increase of the internal temperature. The fact that the temperature increase was more severe after 1 year than immediately after forest thinning confirmed that the microclimate changes due to the removed biomass cannot be recovered in a short time.

The Legal Study of Prohibited Items on Aeroplane for the Aircraft Safety and Security (항공안전보장.질서유지를 위한 항공기반입금지 물품 관리.감독에 관한 입법적 개선방안)

  • Chang, In-Ho
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.29 no.1
    • /
    • pp.33-66
    • /
    • 2014
  • While the numbers of overseas travelers has been increased rapidly each year, the numbers of passengers in the aircraft also has continued to be increased gradually. In the mist of these increasing numbers, such accidents as threatening an aircraft safety like riot, aircraft hijacking and terrorism have happened constantly. In these circumstances, South Korean government has prescribed "Aviation on Security Act" in accordance with the Convention on International Civil Aviation and other international agreements. This act aims to prevent illegal activities and illegal items on the aircraft to ensure the safety and security of civil aviation. However, this act is not sufficiently regulating all the illegal crimes and illegal items on the flight. For the worse, there is a lack of effective supervisory capacity. Likewise, the inherent problems of the current laws relating to the prevention of the illegal items on the aircraft are appearing on the surface continually. Above all, illegal items on the aircraft are directly connected to the issue of aviation safety and security as well as a safe utilization of the flight service. Thus, when there occurs a serious accident on board, it surely would be led to a huge economic loss not mentioning the loss of lives following the accident. Therefore safety of the flight passengers cannot be guaranteed without ensuring the safety of aircraft facilities and good supervisory mechanism of illegal items on the aircraft. Accordingly, establishing a safe operation order tends to influence economy and tourism of a country in no small measure. Therefore, it is an urgent issue to settle down a reasonable and adequate supervisory regulations regarding the prevention of the illegal items on the aircraft. Consequently, in this article, I studied on a reasonal and effective mechanism to control the prevention of the illegal items and illegal acts on the aircraft in order to ensure a safety and security of civil aircraft.

Geomicrobiological Behavior of Heavy Metals in Paddy Soil Near Abandoned Au-Ag Mine Supplied with Carbon Sources (탄소원을 공급한 폐금은광산 주변 논토양 내 중금속의 지구미생물학적 거동 연구)

  • Ko, M.S.;Lee, J.U.;Park, H.S.;Shin, J.S.;Bang, K.M.;Chon, H.T.;Lee, J.S.;Kim, J.Y.
    • Economic and Environmental Geology
    • /
    • v.42 no.5
    • /
    • pp.413-426
    • /
    • 2009
  • The study was conducted to investigate the effects of indigenous bacteria on geochemical behavior of toxic heavy metals in contaminated paddy soil near an abandoned mine. The effects of sulfate amendment to stimulate microbial sulfate reduction on heavy metal behaviors were also investigated. Batch-type experiments were performed with lactate or glucose as a carbon source to activate indigenous bacteria in the soil under anaerobic condition for 100 days. Sulfate (250 mg/L) was artificially injected at 60 days after the onset of the experiments. In the case of glucose supply, solution pH increased from 4.8 to 7.6 while pH was maintained at 7~8 in the lactate solution. The initial low pH in the case of glucose supply likely resulted in the enhanced extraction of Fe and most heavy metals at the initial experimental period. Lactate supply exerted no significant difference on the amounts of dissolved Zn, Pb, Ni and Cu between microbial and abiotic control slurries; however, lower Zn, Pb and Ni and higher Cu concentrations were observed in the microbial slurries than in the controls when glucose supplied. Sulfate amendment led to dramatic decrease in dissolved Cr and maintenance of dissolved As, both of which had gradually increased over time till the sulfate injection. Black precipitates formed in solution after sulfate amendment, and violarite($Fe^{+2}{Ni^{+3}}_2S_4$) was found with XRD analysis in the microbial precipitates. Conceivably the mineral might be formed after Fe(III) reduction and microbial sulfate reduction with coprecipitation of heavy metal. The results suggested that heavy metals which can be readily extracted from contaminated paddy soils may be stabilized in soil formation by microbial sulfate reduction.

Effect of Supplementary Radiation on Growth of Greenhouse-Grown Kales (온실재배 케일의 생장에 미치는 보광효과)

  • Heo, Jeong-Wook;Kim, Hyeon-Hwan;Lee, Kwang-Jae;Yoon, Jung-Boem;Lee, Joung-Kwan;Huh, Yoon-Sun;Lee, Ki-Yeol
    • Korean Journal of Environmental Agriculture
    • /
    • v.34 no.1
    • /
    • pp.38-45
    • /
    • 2015
  • BACKGROUND: For commercial production of greenhouse crops under shorter day length condition, supplementary radiation has been usually achieved by the artificial light source with higher electric consumption such as high-pressure sodium, metal halide, or incandescent lamps. Light-Emitting Diodes (LEDs) with several characteristics, however, have been considered as a novel light source for plant production. Effects of supplementary lighting provided by the artificial light sources on growth of Kale seedlings during shorter day length were discussed in this experiment. METHODS AND RESULTS: Kale seedlings were grown under greenhouse under the three wave lamps (3 W), sodium lamps (Na), and red LEDs (peak at 630 nm) during six months, and leaf growth was observed at intervals of about 30 days after light exposure for 6 hours per day at sunrise and sunset. Photosynthetic photon flux (PPF) of supplementary red LEDs on the plant canopy was maintained at 0.1 (RL), 0.6 (RM), and $1.2(RH){\mu}mol/m^2/s$ PPF. PPF in 3 W and Na treatments was measured at $12{\mu}mol/m^2/s$. Natural light (NL) was considered as a control. Leaf fresh weight of the seedlings was more than 100% increased under the 3 W, Na and RH treatment compared to natural light considering as a conventional condition. Sugar synthesis in Kale leaves was significantly promoted by the RM or RH treatment. Leaf yield per $3.3m^2$ exposed by red LEDs of $1.2{\mu}mol/m^2/s$ PPF was 9% and 16% greater than in 3W or Na with a higher PPF, respectively. CONCLUSION: Growth of the leafy Kale seedlings were significantly affected by the supplementary radiation provided by three wave lamp, sodium lamp, and red LEDs with different light intensities during the shorter day length under greenhouse conditions. From this study, it was suggested that the leaf growth and secondary metabolism of Kale seedlings can be controlled by supplementary radiation using red LEDs of $1.2{\mu}mol/m^2/s$ PPF as well as three wave or sodium lamps in the experiment.

Characterization of Cement Solidification for Enhancement of Cesium Leaching Resistance (세슘 침출 저항성 증진 시멘트 고화체의 제조 및 특성 평가)

  • Kim, Gi Yong;Jang, Won-Hyuk;Jang, Sung-Chan;Im, Junhyuck;Hong, Dae Seok;Seo, Chel Gyo;Shon, Jong Sik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.16 no.2
    • /
    • pp.183-193
    • /
    • 2018
  • Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as $^{137}Cs$ causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing $3000mg{\cdot}L^{-1}$ of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.

Inhibition of Urea Hydrolysis and Nitrification in Upland Soils by Artemisia asiatica Extracts (쑥 추출물(抽出物)의 밭토양중(土壤中) 요소분해(尿素分解), 질산화(窒酸化) 작용(作用) 억제효과(抑制效果))

  • Lim, Sun-Uk;Shin, Myonug-Ho;Park, Hyun-Jun;Kim, Min-Kyun
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.31 no.4
    • /
    • pp.392-399
    • /
    • 1998
  • Nitrogen fertilizers such as urea are readily hydrolyzed in soils to produce ammonium ions which pass through nitrification and denitrification processes. These serial processes have drawn attention due to nitrogen losses, eutrophication, blue baby syndrome, and ozone depletion problems. The purpose of this study was to test the inhibitory effects of hot-water extract and organic solvent fractions of Artemisia asiatica leaves on soil urea hydrolysis and nitrification. In addition, the effects of organic solvent fractions on urease activity and ureolytic bacterial population were also investigated. First, hot-water extract of Artemisia asiatica leaves inhibited soil nitrification substantially with a marginal stimulatory effect on soil urea hydrolysis. Soils treated with hot-water extract of Artemisia asiatica leaves showed significant decreases in the accumulation of soil $NO_3-N$ (~68% decrease) compared with the control soil without the treatment of hot-water extract. In contrast, $CHCl_3$/MeOH fraction and basic aqueous layer of Artemisia asiatica leaves inhibited soil urea hydrolysis very strongly, causing 5.8 and 4.3-fold higher accumulation in amounts of remaining urea-N compared with the non-treated soil. Meanwhile, non of the organic solvent fractions showed any significant effects on soil nitrification inhibition. The inhibition of ureolytic bacterial activity by $CHCl_3$/MeOH fraction and aqueous basic layer of Artemisia asiatica leaves without any effects on urease activity itself led us to conclude that the inhibitions of soil urea hydrolysis were caused by the antagonistic effects on ureolytic bacterial activity.

  • PDF

Efficient Remediation of Petroleum Hydrocarbon-Contaminated Soils through Sequential Fenton Oxidation and Biological Treatment Processes (펜톤산화 및 생물학적 연속처리를 통한 유류오염토양의 효율적 처리)

  • Bae, Jae-Sang;Kim, Jong-Hyang;Choi, Jung-Hye;Ekpeghere, Kalu I.;Kim, Soo-Gon;Koh, Sung-Cheol
    • Korean Journal of Microbiology
    • /
    • v.47 no.4
    • /
    • pp.356-363
    • /
    • 2011
  • The accidental releases of total petroleum hydrocarbons (TPH) due to oil spills frequently ended up with soil and ground water pollution. TPH may be degraded through physicochemical and biological processes in the environment but with relatively slow rates. In this study an attempt has been made to develop an integrated chemical and biological treatment technology in order to establish an efficient and environment-friendly restoration technology for the TPH contaminated soils. A Fenton-like reaction was employed as a preceding chemical treatment process and a bioaugmentation process utilizing a diesel fuel degrader consortium was subsequently applied as a biological treatment process. An efficient chemical removal of TPH from soils occurred when the surfactant OP-10S (0.05%) and oxidants ($FeSO_4$ 4%, and $H_2O_2$ 5%) were used. Bioaugmentation of the degrader consortium into the soil slurry led to an increase in their population density at least two orders of magnitude, indicating a good survival of the degradative populations in the contaminated soils ($10^8-10^9$ CFU/g slurry). TPH removal efficiencies for the Fenton-treated soils increased by at least 57% when the soils were subjected to bioaugmentation of the degradative consortium. However, relatively lower TPH treatment efficiencies (79-83%) have been observed in the soils treated with Fenton and the degraders as opposed to the control (95%) that was left with no treatment. This appeared to be due to the presence of free radicals and other oxidative products generated during the Fenton treatment which might inhibit their degradation activity. The findings in this study will contribute to development of efficient bioremediation treatment technologies for TPH-contaminated soils and sediments in the environment.

Effect of Feeding Levels of Concentrate on the Growth, Feed Availability and Economic Evaluation in Feeds Based on Rice-straw of Growing Black Goats (볏짚 위주 사양 시 육성 흑염소의 농후사료 급여 수준이 발육, 사료이용성 및 경제성에 미치는 영향)

  • Kim, Sang Woo;Kim, Myeong Jik;Kim, Kwan Woo;Kim, Dong Hoon;Kim, Young-Sin;Kim, Hyun;Suh, Sang Won;Park, Seong Bok
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.33 no.4
    • /
    • pp.298-303
    • /
    • 2013
  • This study investigates the effect of a feed concentrate on the growth performance, feed requirement, and rearing expenses of growing black goats. Forty female growing black goats were divided into four groups and fed rice straw (ad libitum) mixed with different levels of the feed concentrate: T1 (1.5%), T2 (1.8%), T3 (2.1%), and T4 (0%, control). The average daily weight gain (body weight per day) was as follows: T1 < T2 < T3 < T4 (50.23, 60.37, 71.46 and 98.90 g/day, respectively) (p<0.05). The intake of rice straw decreased significantly with increase in the concentrate level (p<0.05). Rearing expenses amounted to 46,704, 49,998, 54,701, and 74,613 won for feed concentrate levels of 1.5%, 1.8%, 2.1%, and ad libitum, respectively. Increase in feed concentrate levels led to an increase in rearing expenses. In conclusion, a concentrate level of 2.1% was determined to be idea for a rice-straw-based feed for growing black goats.