• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.1
• /
• pp.77-85
• /
• 2019

Biogasification is a technology that uses organic wastes to reproduce as environmental fuels containing methane gas. Biogasification has attracted worldwide attention because it can produce renewable-energy and stable land treatment with prohibit from landfilling and ocean dumping of organic waste. Biomethane is produced by refining biogas. It is injected into natural gas pipeline or used transportation fuel such as cars and buses. 90 bio-gasification facilities are operating in 2016, and methane gas production is very low due to it is limited to organic wastes such as food waste, animal manure, and sewage sludge. There are seven domestic biomethane manufacturing facilities, and the use of high value-added such as transport fuels and city-gas through upgrading biogas should be expanded. On the other hand, the rapid biogasification of organic wastes in domestic resulted in frequent breakdowns of facilities and low efficiency problems. Therefore, the problem is improving as technical guidance, design and operational technical guidance is developed and field experience is accumulated. However, while improvements in biogas production are being made, there is a problem with low utilization. In this study, the problems of biomethane manufacturing facilities were identified in order to optimize the production and utilization of biogas from organic waste resources. Also, in order to present the design and operation guideline of the gas pretreatment and the upgrading process, we will investigate precision monitoring, energy balance and economic analysis and solutions for on-site problems by facility.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.488-496
• /
• 2018

This study examined the Gangwon Province's current implementation of its elimination of invasive plants and explored a plan to effectively manage invasive plants. The percentage of the distribution of the plants was 39.6% for riverside areas, 23.3% for roadside areas, 12.4% for roadside & riverside areas, and 4.6% for areas around farm land and river banks. To ensure the systematic management of invasive plants, the current study suggests a) developing an invasive plants monitoring and management system; b) reinvigorating the participation of residents, private organizations, and military posts; c) planting of native replacement plants and the conversion of the locations as attractions, and d) nurturing the project for using invasive plants. For policy directions to be pursued based on the results of the study, the following are suggested: a) improving laws and systems regarding invasive plants, b) developing a cooperative system for managing invasive plants, c) implementing the training of civilian professionals, d) implementing the elimination of invasive plants, e) developing replacement plants for cities and counties, f) fostering industries that tap into invasive plants, and g) using the Han River Water System Management Fund for funding and greater efficiency.

• Korean Chemical Engineering Research
• /
• v.57 no.5
• /
• pp.743-748
• /
• 2019

This study focuses on the simulation of wet flue gas desulfurization process for improving the production of gypsum by the utilization of low-grade limestone. At present, high-grade limestone with a $CaCO_3$ content of 94% is used for producing merchantable gypsum. In modeling process, a lot of reactions are considered to develop model. First, the limestone dissolution is simulated by RSTOIC model. Second, SOx absorption and crystallization is used by RCSTR model. Finally the gypsum is separated by using SEPERATORS model. Modeling steps make it easy to reflect further side reactions and physical disturbances. In optimization condition, constraints are set to 93% purity of gypsum, 94% desulfurization efficiency, and total use of limestone at 3710 kg/hr. Under these constraints, the mass flow of low-grade limestone was maximized. As a result, the maximum blending quantity of low-grade limestone for 2,100 kg of high-grade limestone that satisfies constraints is about 1,610 kg.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.17 no.2
• /
• pp.127-137
• /
• 2019

Zr electrorefining is demonstrated herein using Zirlo tubes in a chloride-fluoride mixed molten salt in the presence of $AlF_3$. Cyclic voltammetry reveals a monotonic shift in the onset of metal reduction kinetics towards positive potential and an increase in intensity of the additional peaks associated with Zr-Al alloy formation with increasing $AlF_3$ concentration. Unlike the galvanostatic deposition mode, a radial plate-type Zr growth is evident at the top surface of the salt during Zr electrorefining at a constant potential of -1.2 V. The diameter of the plate-type Zr deposit gradually increases with increasing $AlF_3$ concentration. Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray photoelectron spectroscopy (XPS) analyses for the plate-type Zr deposit show that trace amount of Al is incorporated as Zr-Al alloys with different chemical compositions between the top and bottom surface of the deposit. Addition of $AlF_3$ is effective in lowering the residual salt content in the deposit and in improving the current efficiency for Zr recovery.

• The Journal of the Korea Contents Association
• /
• v.19 no.4
• /
• pp.423-431
• /
• 2019

This study examines the effect of the liability limitation provision (LLP) adoption on firm's cost behavior. In April 2011, Korea introduced the LLP with the purpose of improving the management efficiency by mitigating the risks caused by the manager's failure to make decisions related to business operation. However, there are concerns that the adoption of LLP may lead the manager's moral hazard, so the need for empirical research to verify the effect of the LLP adoption is emphasized. In this study, we analyze the effect of the LLP adoption empirically, focusing on the cost behavior that is affected by the manager's decision making. From the empirical result, we find that LLP adopted companies have strengthened the cost stickiness of selling, general, and administrative costs rather than non-adopted companies. This suggests that the manager of LLP adopted company makes a more active decision to consider adjusting costs in order to prepare for future recovery in sales when sales is reduced. This study presents empirical evidence to prove the policy validity of the adoption of LLP, and we expect that our results can contribute to the capital market and academia.

• International Area Studies Review
• /
• v.22 no.4
• /
• pp.145-166
• /
• 2018

This study is due to global competition, the wall between regions is disappearing, customer needs are diversified, and market and technology are rapidly changing. Future growth engines, the importance of convergence capabilities for industrial competitiveness is being emphasized more. Therefore, companies should seek innovative means to increase the efficiency of the company by establishing optimized global management environment and establishing direction and strategy for utilization of convergence technology by improving industrial competitiveness. Firms must adopt and utilize related new technologies by strengthening their convergence capabilities through dynamic capabilities that are internal resource bases for new product development and process innovation. Globalize markets and technologies can expect higher innovation performance when aligning strategic direction with formalized technology competencies held by the firm and incorporating the convergence capabilities needed for technological innovation into processes. The study focuses on the effects of market and technology orientation on technological innovation performance, whether dynamic and convergence capabilities affect technological innovation performance, and dynamic and convergence capabilities to mediate between market and technology orientation. For the study, we surveyed 51.4% of global and multinational corporations that are internationally active or headquartered overseas. Based on the previous studies, hypotheses were established and the collected data were analyzed through utilization path analysis and Sobel test.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.3
• /
• pp.1-8
• /
• 2019

Steel elevator pit was developed for the purpose of minimizing the excavation, simplifying the construction of the frame and economical efficiency by improving the problems that occurred in the existing reinforced concrete. It is common to apply conventional RC method through excavation to underground structures such as underground floor collector well and elevator pit. In recent years, the use of steel collector well and steel elevator pits to reduce construction costs by minimizing the materials of steel and concrete has been continuously increasing. The steel elevator pit is an underground structure and then the performance of the welding part and the structure system is important. Specimen with only steel plate and concrete without studs could support the load more than 3 times than the specimen with deck only. Therefore, even if there is no stud, the deck (steel plate) rib is formed and the effect of restraining the steel plate and the concrete during the bending action can be expected. However, since sudden fracture in the elevator pit may occur, stud bolt arrangement is necessary for the composite effect of steel plate and concrete. It is expected that the bending strength can be expected to increase by about 15% or more depending with and without stud bolts.

• Journal of Korean Society of Disaster and Security
• /
• v.12 no.1
• /
• pp.35-44
• /
• 2019

In the event of a disaster (or accident), first of all, the ability to respond to an immediate disaster is important. This study investigated the disaster response capacity and the effects of disaster response exercise personnel. A questionnaire consisting of 28 items was used to assess disaster response capabilities. The questionnaire consists of contrast, preparedness initial response, warning, and response steps. Survey participants are self-service fire-fighters of small and medium-sized manufacturing companies participating in exercise. The effectiveness of the exercise. was measured by dividing the subjects before and after the exercise. Analyzing the difference between before and after exercise, it was confirmed that disaster response exercise. had significant effects on improving disaster response capacity. This study suggests that the disaster response exercise. has the effect on the disaster response capacity of the members and the necessity of disaster response exercise. As in the case study, if a company or organization regularly conducts disaster response exercise., its disaster response capabilities will improve. In addition, it is anticipated that in the event of a disaster (or accident), it will be possible to prevent or reduce property damage as well as property damage.

• The Korean Journal of Archival Studies
• /
• no.49
• /
• pp.277-297
• /
• 2016

Access re-review is a process to reclassify the non-disclosure documents to open accessible documents, and it has to be performed in every five years. However, current procedures of the access re-review in many archives have not been properly working, due to the shortage of the available archivists for providing enough access re-review. Although many difficult situation for the re-review such as enormous amount of re-review documents and lack of archivists, access re-review was included in the administrative evaluation list, of which it makes the re-review for just evaluating process. In this study, the access re-review of Seoul Metropolitan Office of Education, which have performed by external service companies as well as the other institutions' progresses were summarized for improving access re-review process. Although Seoul Metropolitan Office of Education processed 610,000 re-review with 100,000,000 won budget for 4 years, the project has been failed to get more budget support because of the claim for the budget efficiency. The other institutions also could not focus on the actual access re-review. Considering all the points, current access re-review process is clearly required to be improved.

• Korean Journal of Microbiology
• /
• v.54 no.4
• /
• pp.420-427
• /
• 2018

The orthogonal pair of Saccharomyces cerevisiae tyrosyl-tRNA synthetase (Sc YRS) and a variant of E. coli initiator tRNA, fMam $tRNA_{CUA}$ which recognizes the amber stop codon is an effective tool for site-specific incorporation of unnatural amino acids into the protein in E. coli. To evolve the amber suppression activity of the orthogonal pair, we generated a mutant library of Sc YRS by randomizing two amino acids at 320 and 321 which involve recognition of the first base of anticodon in fMam $tRNA_{CUA}$. Two positive clones are selected from the library screening with chloramphenicol resistance mediated by amber suppression. They showed growth resistance against high concentration of chloramphenicol and their $IC_{50}$ values were approximately 1.7~2.3 fold higher than the wild type YRS. In vivo amber suppression assay reveals that mutant YRS-3 (mYRS-3) clone containing amino acid substitutions of P320A and D321A showed 6.5-fold higher activity of amber suppression compared with the wild type. In addition, in vitro aminoacylation kinetics of mYRS-3 also showed approximately 7-fold higher activity than the wild type, and the enhancement was mainly due to the increase of tRNA binding affinity. These results demonstrate that optimization of anticodon recognition by engineered aminoacyl tRNA synthetase improves the efficiency of unnatural amino acid incorporation in response to nonsense codon.