• Title/Summary/Keyword: chemical states

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Analysis of global trends on smart manufacturing technology using topic modeling (토픽모델링을 활용한 주요국의 스마트제조 기술 동향 분석)

  • Oh, Yoonhwan;Moon, HyungBin
    • Journal of Korea Society of Industrial Information Systems
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    • v.27 no.4
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    • pp.65-79
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    • 2022
  • This study identified smart manufacturing technologies using patent and topic modeling, and compared the technology development trends in countries such as the United States, Japan, Germany, China, and South Korea. To this purpose, this study collected patents in the United States and Europe between 1991 and 2020, processed patent abstracts, and identified topics by applying latent Dirichlet allocation model to the data. As a result, technologies related to smart manufacturing are divided into seven categories. At a global level, it was found that the proportion of patents in 'data processing system' and 'thermal/fluid management' technologies is increasing. Considering the fact that South Korea has relative competitiveness in thermal/fluid management technologies related to smart manufacturing, it would be a successful strategy for South Korea to promote smart manufacturing in heavy and chemical industry. This study is significant in that it overcomes the limitations of quantitative technology level evaluation proposed a new methodology that applies text mining.

Proximate Content Monitoring of Black Soldier Fly Larval (Hermetia illucens) Dry Matter for Feed Material using Short-Wave Infrared Hyperspectral Imaging

  • Juntae Kim;Hary Kurniawan;Mohammad Akbar Faqeerzada;Geonwoo Kim;Hoonsoo Lee;Moon Sung Kim;Insuck Baek;Byoung-Kwan Cho
    • Food Science of Animal Resources
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    • v.43 no.6
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    • pp.1150-1169
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    • 2023
  • Edible insects are gaining popularity as a potential future food source because of their high protein content and efficient use of space. Black soldier fly larvae (BSFL) are noteworthy because they can be used as feed for various animals including reptiles, dogs, fish, chickens, and pigs. However, if the edible insect industry is to advance, we should use automation to reduce labor and increase production. Consequently, there is a growing demand for sensing technologies that can automate the evaluation of insect quality. This study used short-wave infrared (SWIR) hyperspectral imaging to predict the proximate composition of dried BSFL, including moisture, crude protein, crude fat, crude fiber, and crude ash content. The larvae were dried at various temperatures and times, and images were captured using an SWIR camera. A partial least-squares regression (PLSR) model was developed to predict the proximate content. The SWIR-based hyperspectral camera accurately predicted the proximate composition of BSFL from the best preprocessing model; moisture, crude protein, crude fat, crude fiber, and crude ash content were predicted with high accuracy, with R2 values of 0.89 or more, and root mean square error of prediction values were within 2%. Among preprocessing methods, mean normalization and max normalization methods were effective in proximate prediction models. Therefore, SWIR-based hyperspectral cameras can be used to create automated quality management systems for BSFL.

The Changes and the Determinants of Korea's Market Share in U.S., Japanese, and Other DECO Imports (한국수출(韓國輸出)의 시장점유율(市場占有率) 분석(分析) : 대미(對美)·日(일)·여타(餘他) OECD 수출실적(輸出實績)을 중심으로)

  • Yoo, Jung-ho
    • KDI Journal of Economic Policy
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    • v.13 no.4
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    • pp.3-30
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    • 1991
  • This paper examines Korea's exports of manufactures to the United States, Japan, and other OECD member countries in the 1974-89 period, focusing on the market share in the trade partners' imports. It decomposes the growth of exports into various effects, following the "constant-market-shares" analysis. For this purpose, the entire period is divided into three subperiods: 1974-78, 1978-83, and 1983-89. The paper also estimates a regression model of the market share determination, using the data of Korea's market share in U.S. imports. In the three subperiods under study, Korea's exports grew at different paces for varied reasons. The average annual growth rate was 28 %, 11 %, and 21 %, respectively. A large drop in the "competitiveness effect", that is, in the market-share growth rate, was mainly responsible for the decline in the export growth rate. The largest drop in the competitiveness effect was found in the light manufactures exports in the second period. The market share did not regain the rapid growth momentum. The main reason for the rise in export growth rate in the last subperiod was the "market-size effect"-a rise in the growth rate of the trade partners' imports. According to the regression results, high intensities in physical and human capital tended to lower the Korean manufacturing industries' market shares in the United States. This negative correlation was stronger in the case of human capital intensity, suggesting that Korea is relatively poorer in human capital endowment than in physical capital endowment when compared to the United States. This negative correlation between the market share and each of the two intensities became weaker overtime. This may be interpreted as the consequence of both physical and human capital accumulation which were faster than the labor force growth. Depreciation of the Japanese yen was estimated to have a negative influence on the Korean manufacturing industries' market share in the United States, and this negative influence became stronger each year in the 1980s. This seems to reflect the intensifying competition between the two countries' exports in U.S. import markets. The Heavy and Chemical Industry Policy of the 1970s, which promoted a number of selected industries by providing them with various incentives and inevitably discriminated against the rest of the industries, was estimated to have had strong negative effects on the export performance of the light manufacturing industries. This finding and the largest decline in the "competitiveness effect" -found in the light manufactures exports in the 1978-83 period-indicate that the Heavy and Chemical Industry Policy was mainly accountable for the drop in the export growth rate during the period. On the other hand, the rise in export growth rate during the subsequent subperiod was greatly impacted by the large scale exchange rate realignments of major currencies, especially by the appreciation of the Japanese yen, and other changes in international economic conditions.

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A Study on Selecting Personal Protective Equipment for Listed Hazardous Chemicals (2): Analysis Using an Exposure Risk Matrix (사고대비물질 개인보호구 선정에 관한 연구(2): 노출위해성 매트릭스에 의한 분석)

  • Han, Don-Hee;Chung, Sang-Tae;Kim, Jong-Il;Cho, Yong-Sung;Lee, Chung-Soo
    • Journal of Environmental Health Sciences
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    • v.42 no.6
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    • pp.430-437
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    • 2016
  • Objectives: The new Chemical Control Act from the Korean Ministry of Environment (2014-259) simply states only in basic phrases that every worker handling the listed chemicals should wear personal protective equipment (PPE) and does not consider the different hazard characteristics of particular chemicals or work types. The purpose of this study was to produce an exposure risk matrix and assign PPE to the categories of this matrix, which would be useful for revising the act to suggest PPE to suit work types or situations. Methods: An exposure risk matrix was made using hazard ranks of chemicals and workplace exposure risks in the previous study. For the 20 categories of exposure risk matrix PPE, levels A, B, C, D as classified by OSHA/EPA were assigned. After 69 hazardous chemicals were divided into 11 groups according to their physiochemical characteristics, respirators, chemical protective clothing (CPC), gloves and footwear were suggested on the basis of the assigned PPE levels. Results: PPE table sheets for the 11 groups were made on the basis of work types or situations. Full facepiece or half-mask for level C was recommended in accordance with the exposure risk matrix. Level A was, in particular, recommended for loading or unloading work. Level A PPE should be worn in an emergency involving hydrogen fluoride because of the number of recent related accidents in Korea. Conclusion: PPE assignment according to the exposure risk matrix made by chemical hazards and work type or situation was suggested for the first time. Each type of PPE was recommended for the grouped chemicals. The research will be usefully used for the revision of the Chemical Control Act in Korea.

A Study on 2010 Beijing Convention for Antiterrorism of International Aviation - Compared Beijing Convention(2010) with Montreal Protocol - (국제항공테러방지 북경협약(2010)에 관한 연구 - 몬트리올협약과의 비교를 중심으로 -)

  • Hwang, Ho-Won
    • The Korean Journal of Air & Space Law and Policy
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    • v.25 no.2
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    • pp.79-112
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    • 2010
  • The Beijing Convention of 2010 taken together effectively establishes a new broader and stronger civil aviation security framework. This adoption would significantly advance cooperation in prevent of the full range of unlawful acting relation to civil aviation and the prosecution and punishment of offenders. First, the Beijing Convention of 2010 will require parties to criminalize a number of new and emerging threats to the safety of civil aviation, including using aircraft as a weapon and organizing, directing and financing acts of terrorism. These new treaties reflect the international community's shared effort to prevent acts of terrorism against civil aviation and to prosecute and punish those who would commit them. Second, this convention will also require States to criminalize the transport of biological, chemical, nuclear weapons and related material. These provisions reflect the nexus between non-proliferation and terrorism and ensure that the international community will act to combat both. Third, this Convention shall not apply to aircraft used in military, customs or police services. As a substitute, International Humanitarian Law will be applied in a case. Moreover, the National Jurisdiction and the application of the law will be extended farther. The treaty promotes cooperation between States while emphasizing the human rights and fair treatment of terrorist suspects.

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Effects of Pretreatment of Alkali-degreasing Solution for Cu Seed Layer (약알칼리탈지 용액에서의 구리 Seed 층의 전처리 효과)

  • Lee, Youn-Seoung;Kim, Sung-Soo;Rha, Sa-Kyun
    • Journal of the Korean Vacuum Society
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    • v.21 no.1
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    • pp.6-11
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    • 2012
  • In order to understand a process of contaminants removal on surface of Cu seed layer (Cu seed/Ti/Si) by sputter deposition, we investigated the changed morphology and states of Cu seed surface after pretreatment in alkali degreasing Metex TS-40A solution according to dipping time. After TS-40A pretreatment, the surface morphology with clearer grains was observed by Field emission scanning electron microscope and the changed surface chemical states and impurities on surface of samples were checked by X-ray photoelectron spectroscopy. Dipping time in TS-40A solution had very little effect on surface of Cu seed layer. After pretreatment, much carbons and little oxygens on surface of Cu seed were eliminated and the decrease of peaks corresponded to O=C and $Cu(OH)_2$ was estimated. However, Si content (=silicate) was detected on sample surface. We think that the silicate impurity forms on Cu seed by chemical reaction of TS-40A solution included silicate component. By pretreatment of alkali degreasing Metex TS-40A solution, it showed an excellent effect in removal of O=C and $Cu(OH)_2$ on Cu seed layer, but the silicate was formed on surface of Cu seed. Therefore, another cleaning process such as acid cleaning is required for removal of this silicate in use of this alkali degreasing.

The Influences of Reciprocal Peer Tutoring Strategy and Field Independence-Dependence in Instruction Enhancing Student Questions by Using Weekly Reports (주단위 보고서를 활용한 질문 촉진 수업에서 상호동료교수 전략 및 장독립성-장의존성의 영향)

  • Kang, Hun-Sik;Kwon, Eun-Kyung;Noh, Tae-Hee
    • Journal of the Korean Chemical Society
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    • v.51 no.1
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    • pp.82-92
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    • 2007
  • This study investigated the influences of reciprocal peer tutoring strategy and field independencedependence in the instruction enhancing student questions by using weekly reports. Seventh graders (N=152) from a middle school were assigned to WR (weekly reports) and WR-RPT (weekly reports-reciprocal peer tutoring) groups. Students were taught about ‘three states of matter', ‘motion of molecules', and ‘change of states and thermal energy for eighteen class hours and wrote weekly reports six times for the period. The students in the WR-RPT group also conducted reciprocal peer tutoring with the questions of weekly reports which they wrote. The results revealed that the scores of the WR-RPT group were significantly higher than those of the WR group in a conception test regardless of students' field independence-dependence. The field dependent students in the WR-RPT group performed better in an achievement test than those in WR group, while there was no significant difference for the field independent stu dents between the two groups. Additionally, field independent students in each group scored significantly higher than field dependent students in the two tests. Many students, especially having more field independence in the WR-RPT group, perceived WR-RPT positively.

Electronic Structure of Iron and Molybdenum in $Li_2FeMoO_4Cl$ and Its Crystal Symmetry ($Li_2FeMoO_4Cl$의 결정구조와 Fe 및 Mo의 전자구조 연구)

  • Choy, Jin-Ho;Park, Nam-Gyu;Chang, Soon-Ho;Park, Hyung-Ho
    • Journal of the Korean Chemical Society
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    • v.39 no.6
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    • pp.446-452
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    • 1995
  • Lithium intercalates, $Li_xFeMoO_4Cl$ ($1{\leq}X{\leq}2$) prepared by electrochemical lithiation of $FeMoO_4Cl$ crystallizes in monoclinic structure for all x values as revealed by x-ray diffraction and galvanostatic discharge experiments. According to the x-ray photoelectron spectroscopic study, Fe(III) is at first reduced to Fe(II) upon lithium intercalation with the x domain of $0{\leq}X{\leq}1$, where the crystal symmetry is changed from tetragonal to monoclinic. On the other hand, Mo(VI) is reduced to lower valent state upon further lithium intercalation ($1{\leq}X{\leq}2$), where no crystal symmetry transformation and reduction of Fe(II) to lower valent state are observed. The Mo 3d spectrum for $Li_2FeMoO_4Cl$ appears as a complex shape, but can be deconvoluted into the three sets of the doublet on the basis of Gaussian function, those which correspond to Mo(VI), Mo(V) and Mo(IV) states, respectively. The mixed valent states of molybdenum after further lithiation may be due to a competitive reaction between the formation of Mo(V) and its disproportionation to Mo(IV) and Mo(VI).

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Theoretical Studies of the Gas-Phase Identity Nucleophilic Substitution Reactions of Cyclopentadienyl Halides

  • Lee, Ik-Choon;Li, Hong-Guang;Kim, Chang-Kon;Lee, Bon-Su;Kim, Chan-Kyung;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.24 no.5
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    • pp.583-592
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    • 2003
  • The gas phase identity nucleophilic substitution reactions of halide anions (X = F, Cl, Br) with cyclopentadienyl halides (1) are investigated at the B3LYP/6-311+G**, MP2/6-311+G** and G2(+)MP2 levels involving five reaction pathways: σ-attack $S_N2$, β-$S_N$2'-syn, β-$S_N$2'-anti, γ-$S_N$2'-syn and γ-$S_N$2'-anti paths. In addition, the halide exchange reactions at the saturated analogue, cyclopentyl halides (2), and the monohapto circumambulatory halide rearrangements in 1 are also studied at the same three levels of theory. In the σ-attack $S_N2$ transition state for 1 weak positive charge develops in the ring with X = F while negative charge develops with X = Cl and Br leading to a higher energy barrier with X = F but to lower energy barriers with X = Cl and Br than for the corresponding reactions of 2. The π-attack β-$S_N$2' transition states are stabilized by the strong $n_C-{\pi}^{*}_{C=C}$ charge transfer interactions, whereas the π-attack γ-$S_N$2' transition states are stabilized by the strong $n_C-{\sigma}^{*}_{C-X}$ interactions. For all types of reaction paths, the energy barriers are lower with X = F than Cl and Br due to the greater bond energy gain in the partial C-X bond formation with X = F. The β-$S_N$2' paths are favored over the γ-$S_N$2' paths only with X = F and the reverse holds with X = Cl and Br. The σ-attack $S_N2$ reaction provides the lowest energy barrier with X = Cl and Br, but that with X = F is the highest energy barrier path. Activation energies for the circumambulatory rearrangement processes are much higher (by more than 18 kcal $mol^{-1}$) than those for the corresponding $S_N2$ reaction path. Overall the gas-phase halide exchanges are predicted to proceed by the σ-attack $S_N2$ path with X = Cl and Br but by the β-$S_N$2'-anti path with X = F. The barriers to the gas-phase halide exchanges increase in the order X = F < Br < Cl, which is the same as that found for the gas-phase identity methyl transfer reactions.

A Study on tne Necessity of Using ESG to Prevent Accidents in the Chemical Industry (화학산업 사고 예방을 위한 ESG 활용 필요성 연구)

  • Cheolhee Yoon;Leesu Kim;Seungho Jung;Keun-won Lee
    • Journal of the Society of Disaster Information
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    • v.19 no.4
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    • pp.826-833
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    • 2023
  • Purpose: We suggest the need to utilize ESG in the safety field to prevent serious industrial accidents. Method: The Serious Accident Punishment Act, a strong serious accident prevention system, was reviewed through a review of previous research. And through comparative analysis of serious accident data from the United States and Korea, the main causes of accidents in the domestic chemical industry were derived. Result: It was determined that there was a need to induce voluntary safety management by companies through ESG management along with the Serious Accident Punishment Act, which aims to prevent corporate accidents. Through statistical analysis of accident data, it was confirmed that the scale of damage and number of deaths in domestic accidents was greater than in the United States. The reason was interpreted to be that there are many accidents caused by human causes in the country. Conclusion: In order to compensate for the lack of voluntariness in corporate safety management as well as the Serious Accident Punishment Act and encourage active safety management, the proportion of 'ESG safety evaluation' must be expanded. By using ESG as an indirect social sanction, we can expect companies to voluntarily and actively manage safety and expand safety investments in the safety field.