• The Journal of Engineering Geology
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• v.32 no.4
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• pp.627-642
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• 2022

The world's long reliance on fossil fuels (e.g., oil, coal, and natural gas) is severely changing its environment and climate. Energy research has focused on developing hydrogen as the most promising energy carrier and a key technology for sustainable energy development. Hydrogen can be classified as gray, blue, green, and otherwise according to the raw materials and methods used for production and processing. For the development of hydrogen energy, geologists are attempting to identify the mechanism of abiotic hydrogen generation by serpentinization or hydrothermal alteration. Teams in the United States, France, and Australia have researched laboratory-scale hydrogen production through water-rock interactions under various conditions, whereas there has been almost no research on abiotic hydrogen in South Korea. This paper reviews the current state of international research on hydrothermal alteration and offers suggestions for future investigations of abiotic hydrogen production in South Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.946-954
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• 2022

More than half of barges have been surveyed and designated as an "unmanned barge". The main advantage of the unmanned barge is that it can carry more cargo equivalent to 25 percent of freeboard compared to that of a manned barge. In contrast, it needs an onboard crew barge because the bargeman is in charge of several tasks during sailing such as mooring or unmooring barges to or from a wharf, dropping and heaving up an anchor and turning on and of navigational lights and shapes. The instant recognition is that a tug assume the responsibility of operating a barge; however, different situations exist in which the shipper, as the operator of the barge, hires a tug. Although a tug might be a carrier of a barge under a specific contract, the master of the tug should fulfill his duty to complete its voyage. Most masters are not provided with the particulars of a barge and the information regarding the bargemen onboard, which is believed not to respect the master's authority and lead to an unintended violation of relevant laws. This paper presents three recommendations for resolving these issues: the policy approach for changing unmanned barges to manned barges, issuing a minimum safe manning certificate, and providing the master of tug information on the barge and the crew onboard. Thus, the proposed approach can be expected to improve the crew's working conditions, diminish the violation of the maximum number of persons onboard the barge, and ensure the authority of the master of tug through such recommendations.

• Membrane Journal
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• v.32 no.4
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• pp.218-226
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• 2022

Hydrogen, a carrier of large-capacity chemical and clean energy, is an important industrial gas widely used in the petrochemical industry and fuel cells. In particular, hydrogen is mainly produced from fossil fuels through steam reforming and gasification, and carbon dioxide is generated as a by-product. Therefore, in order to obtain high-purity hydrogen, carbon dioxide should be removed. This review focused on free-standing polymeric membranes and mixed-matrix membranes (MMMs) that separate hydrogen from carbon dioxide reported in units of Barrer [1 Barrer = 10^-10 cm³ (STP) × cm / (cm² × s × cmHg)]. By analyzing various recently reported papers, the structure, morphology, interaction, and preparation method of the membranes are discussed, and the structure-property relationship is understood to help find better membrane materials in the future. Robeson's upper bound limits for hydrogen/carbon dioxide separation were presented through reviewing the performance and characteristics of various separation membranes, and various MMMs that improve separation properties using technologies such as crosslinking, blending and heat treatment were discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.86-97
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• 1988

Sesame(Sesamum indicum L.) is probably the most ancient oilseed crop known in the world. The seed of sesame is used in a variety of ways as food. The whole seed may be eaten raw, either roasted or parched, or fed to birds and stock. Sesame oil is used as a salad or cooking oil, in shortening, margarine and in the manufacture of soap. Minor uses are as a fixative in the perfume industry and formerly as a carrier for fatsoluble substances in pharmaceuticals such as penicillin. One of the minor constituents of sesame oil, sesamin, is used for its synergistic effect in pyrethrin insecticides, in addition of a small quantity of this substance markedly increases the effectiveness of fly sprays. The meal remaining after oil extraction can be used as and animal feed-stuff or as manure. In general sesame meal is considered to be equal to cottonseed or soybean meal as a protein supplement for livestock and poultry. It is especially high in certain amino-acids such as methionine, which is low in soybean meal, and thus can be combined with it or similar meal to form a more balanced ration. An attempt to summarize the literature review on quality improvement of sesame was made to discuss the accomplishments of the past and perspectives in the future. The reviews on quality improvement of sesame were mainly discussed in connection with the cultural practices and genetic informations in current status. The emphasis focussed on environmental variation of quality in cultural practices, such as harvest time, variety by location, climatic condition, fertilizer application, and growth regulator treatment. On the genetic variation of quality, it was discussed on variety background, mutation breeding, correlations, and inheritance of quality related characteristics. It also was discussed on relationship between quality and plant traits, storage condition or period, and seed coat color. Moreover, current research status were reviewed on some minor elements such as sesamin, oxalic acid, and trypsin inhibitor. As a results of the review, the lack of an effort to quality improvement in each utilization area was indicated as a problem area. More active efforts for the improvement of quality were also insufficient to incorporate the available genes for quality in breeding method or collection and analysis of breeding materials. Therefore, researches in the future would be recommended to emphasize on these problem areas.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.81-81
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• 2003

The stochiometric mixture of evaporating materials for the CuGaSe$_2$ single crystal thin films were prepared from horizontal furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal CuGaSe$_2$, it was found tetragonal structure whose lattice constant no and co were 5.615$\AA$ and 11.025$\AA$, respectively. To obtains the single crystal thin films, CuGaSe$_2$ mixed crystal was deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were 61$0^{\circ}C$ and 45$0^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about 0.5${\mu}{\textrm}{m}$/h. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of van der pauw and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by pizoelectric scattering in the temperature range 30K to 150K and by polar optical scattering in the temperature range 150K to 293K. The optical energy gaps were found to be 1.68eV for CuGaSe$_2$ single crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation then the constants in the Varshni equation are given by a=9.615$\times$ 10$^{-4}$ eV/K, and $\beta$=335K. From the photocurrent spectra by illumination of polarized light of the CuGaSe$_2$ single crystal thin films. We have found that values of spin orbit coupling ΔSo and crystal field splitting ΔCr was 0.0900eV and 0.2498eV, respectively. From the PL spectra at 20K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be 0.0626eV and the dissipation energy of the acceptor-bound exciton and donor-bound exciton to be 0.0352eV, 0.0932eV, respectively.

• Clean Technology
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• v.29 no.3
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• pp.185-192
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• 2023

This study was conducted to obtain basic process simulation data before conducting pyrolysis experiments for the development of a thermochemical conversion system by recirculation of heat carrier and gases thereby. In this study, polypropylene (PP) was used as a pyrolysis sample material as an alternative to waste plastics, and fluid sand was used as a heat transfer medium in the system. Manganese (Mn) was chosen as the catalyst for the pyrolysis experiment, and the catalyst pyrolysis was performed by impregnating it in the sand. The basic properties of PP were analyzed using a thermogravimetric analyzer (TGA), and liquid oil was generated through catalytic pyrolysis under a nitrogen atmosphere at 600℃. The carbon number distribution of the generated liquid oil was confirmed by GC/MS analysis. In this study, the effects of the presence and the amount of Mn loading on the yield of liquid oil and the distribution of hydrocarbons in the oil were investigated. When Mn/sand was used, the residue decreased and the oil yield increased compared to pyrolysis using sand alone. In addition, as the Mn loading increased, the ratio of C₆~C₉ range gasoline in the liquid oil gradually increased, and the distribution of diesel and heavy oil with more carbon atoms than C₁₀ in the oil decreased. In conclusion, it was found that using Mn as a catalyst and changing the amount of Mn could increase the yield of liquid oil and increase the gasoline ratio in the product.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.2
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• pp.119-125
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• 2021

⁸²Sr for ⁸²Rb generator was produced through the irradiation of the proton beam on the ^nat.RbCI target at the target irradiation facility installed at the end of the Rl-dedicated beamline of the 100 MeV proton linear accelerator of KOMAC (Korea Multi-purpose Accelerator Complex). The average current of the proton beam was 1.2 µA for irradiation time of 150 min. For the separation and purification of the ⁸²Sr from ^nat.RbCI irradiated, Chelex-100 resin was used. The activities of ⁸²Sr in the irradiated ^nat.RbCI target solution and after purification were 45.29 µCi and 43.4 µCi, respectively. The separation and purification yield was 95.8%. As an adsorbent to be filled in the generator for ⁸²Sr adsorption hydrous tin oxide was selected. The adsorption yield of ⁸²Sr into the generator adsorbent was > 99 %, and the total amount of ⁸²Sr adsorbed to the generator was 21.6 µCi as of the day of the ⁸²Rb elution experiment. When the elution amount was 22 mL, the maximum⁸²Rb elution yield was 93.3%, and the elution yield increased as the flow rate increased. After the eluted ⁸²Rb was filled in the correction phantom of the small PET for animals, a PET image was taken. The image scan time was set to 5 min, and the phantom PET image was successfully obtained. As results of impurity analysis on eluted ⁸²Rb using ICP-MS, ^nat.Rb stable isotopes that compete in vivo of ⁸²Rb were identified as undetected levels and were determined to be No-Carrier-Added (NCA).

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.786-794
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• 2022

Green ammonia is a promising renewable energy carrier. Green ammonia can be used in various energy conversion devices (e.g., engine, fuel cell, etc.). Ammonia has to be fed with hydrogen for start-up and failure protection of some energy conversion devices. Ammonia can be converted into hydrogen by decomposition and partial oxidation. Especially, partial oxidation has the advantages of fast start-up, thermally self-sustaining operation and compact size. In this paper, thermodynamics, start-up and operation characteristics of ammonia partial oxidation were investigated. O₂/NH₃ ratio, ammonia flow rate and catalyst volume were varied as operation parameters. In thermodynamic analysis, ammonia conversion was maximized in the O₂/NH₃ range from 0.10 to 0.15. Ammonia partial oxidation reactor was successfully started using 12 V glow plug. At 0.13 of O₂/HN₃ ratio and 10 LPM of ammonia flow rate, ammonia partial oxidation reactor showed 90% of ammonia conversion over commercial Ru catalyst. In addition, Increasing O₂/NH₃ ratio from 0.10 to 0.13 was more effective for high ammonia conversion than increasing catalyst volume at 0.10 of O₂/NH₃.

• Journal of Popular Narrative
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• v.25 no.1
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• pp.193-215
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• 2019

According to ethical literary criticism, every type of literature has its text. The original definition of oral literature refers to the literature disseminated orally. Before the dissemination, the text of oral literature is stored in the human brain, which is termed as "brain text". Brain text is the textual form used before the formation of writing symbols and its application to a recording of information, and it still exists after the creation of writing symbols. Other types of texts are written text and electronic text. Brain text consists of brain concepts, which, according to different sources, can be divided into objective concepts and abstractive concepts. Brain concepts are tools for thinking while thought comes from thinking with understanding and an application of brain concepts. Brain text is the carrier of thought. The termination of the synthesis of brain concepts signifies the completion of thinking, which produces thoughts to form brain text. Brain text determines thinking and behavioral patterns that not only communicate and spread information, but also decide our ideas, thoughts, judgments, choices, actions and emotions. Brain text is also a deciding factor for our lifestyle and moral behaviors. The nature of a person's brain text determines his thoughts and actions, and most importantly determines who he is.

• Korea Trade Review
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• v.41 no.5
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• pp.187-211
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• 2016

This study discusses the right of suspension of performance against anticipatory breach under SGA. Anticipatory breach originated in Hochster v De La Tour allows the innocent party to exercise immediately the right or rights reserved for the non-performance of obligations. But it has not been codified in English Law. Instead, under SGA s. 41 and s. 44, the seller may suspend his performance against the buyer' anticipatory breach. Lien under s. 41 and stoppage in transit under s. 44 are given only to the seller in a narrowly-defined situation. Under SGA s. 41, the unpaid seller is entitled to retain possession of goods where the buyer becomes insolvent. But under SGA s. 43, the unpaid seller loses the right of lien when he delivers goods to a carrier or other bailee or custodian for the purpose of transmission to the buyer without reserving the right of disposal, or when the buyer or his agent lawfully obtains possession of the goods, or by waiver of lien. Under SGA s. 44, the unpaid seller may exercise the right of stoppage in transit if the buyer becomes insolvent, despite the fact that the property of goods has passed or a bill of lading has been transferred to the buyer. But, under s. 45, the right of stoppage in transit is ended when the buyer or his agent takes delivery of goods. And where the buyer transfers a bill of lading to a sub-buyer, the unpaid seller loses his right to stop goods in transit.