• Nuclear Engineering and Technology
• /
• v.55 no.2
• /
• pp.523-529
• /
• 2023

Cemented uranium tailings backfill created from alkali-activated slag (CUTB) is an effective method of disposing of uranium tailings. Using some environmental functional minerals with ion exchange, adsorption, and solidification abilities as backfill modified materials may improve the leaching resistance of the CUTB. Natural zeolite, which has good ion exchange and adsorption characteristics, is selected as the backfill modified material, and it is added to the backfill materials with cementitious material proportions of 4%, 8%, 12%, and 16% to prepare CUTB mixtures with environmental functional minerals. After the addition of natural zeolite, the uniaxial compressive strength (UCS) of the CUTB decreases, but the leaching resistance of the CUTB increases. When the natural zeolite content is 12%, the UCS reaches the minimum value of 8.95 MPa, and the concentration of uranium in the leaching solution is 0.28-8.07 mg/L, the leaching rate R₄₂ is 9.61×10^-7 cm/d, and cumulative leaching fraction P₄₂ is 8.53×10^-4 cm, which shows that the alkali-activated slag cementitious material has a good curing effect on the CUTB, and the addition of environmental functional minerals helps to further improve the leaching resistance of the CUTB, but it reduces the UCS to an extent.

• Environmental and Resource Economics Review
• /
• v.9 no.2
• /
• pp.285-309
• /
• 2000

One of the main issues in natural resource economics is estimating the amount of stock and the biological growth functions of renewable natural resources. Since the stock level is not directly observed the usual econometric approaches cannot be employed for this purpose. The maximum entropy approach has been suggested as a useful alternative to estimate the dynamic model of natural resource use. This study estimates the stock and the growth function of Korean anchovy using the data for yield and yield efforts. The results show that the current level of anchovy yield exceeds its maximum sustainable yield, which implies that the stock will decrease substantially over time.

• Resources Recycling
• /
• v.29 no.3
• /
• pp.24-35
• /
• 2020

Management of resource productivity is important for the reduction of natural resources and energy consumption. This is closely linked to circular economy which has recently been stressed worldwidely. Resource productivity is a key indicator which is to be managed in various industry sectors. Especially Korea which is heavily dependent on the natural resources import from overseas needs to give attention to this point. Nevertheless resource productivity related domestic researches and policies are extremely rare. This paper thus presents trends on resources productivities and their management policies of European countries and OECD G7 countries compared to the situation of Korea. In addition, the decoupling phenomenon of DMC (domestic material consumption) and GDP of Europe is analyzed and the resource productivity promotion strategy of Korea is proposed.

• Environmental and Resource Economics Review
• /
• v.13 no.4
• /
• pp.735-761
• /
• 2004

As a possible alternative to Traditional Discounted Cash Flow Method, "Option Pricing Model" has drawn academic attentions for the last a few decades. However, it has failed to replace traditional DCF method practically due to its mathematical complexity. This paper introduces an option pricing valuation model specifically adjusted for the natural resource development projects. We add market information and industry-specific features into the model so that the model remains objective as well as realistic after the adjustment. The following two features of natural resource development projects take central parts in model construction; product price is a unique source of cash flow's uncertainty, and the projects have cost structure from capital-intense industry, in which initial capital cost takes most part of total cost during the projects. To improve the adaptability of Option Pricing Model specifically to the natural resource development projects, we use Two-Factor Model and Long-term Asset Model for the analysis. Although the model introduced in this paper is still simple and reflects limited reality, we expect an improvement in applicability of option pricing method for the evaluation of natural resource development projects can be made through the process taken in this paper.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.6
• /
• pp.1625-1632
• /
• 2014

A concise and efficient one-pot synthesis of chroman-2,4-dione-based HKA derivatives by three component reaction of HKAs, triethoxymethane and 4-hydroxycoumarin derivatives under solvent-free and catalyst-free conditions is described. This protocol has many advantages, in that the GAP (Group-Assistant-Purification) chemistry process is involved in this method. As a result, the experimenter can avoid cumbersome process steps such as traditional chromatography and recrystallization purifications. The desired products can be easily obtained by washing the crude products with 95% EtOH.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.359-359
• /
• 2017

A new soybean cyst nematode, H. sojae was reported from Korea in 2016. This species is closely related to H. glycines which has the same host plant. Morphological observations of the cyst, female, male and second-stage juveniles indicated that this species is differed from H. glycines. Especially, cysts of H. sojae appeared more round, shining and darker than that of H. glycines. The distribution of this new cyst nematode in soybean field in Korea is unknown so far. In 2016, 270 soil samples were collected from soybean fields and examined the existence of H. glycines and H. sojae. Total of 111 samples contained cysts (41.1%). Among them 77% were H. glycines and 23% were H. sojae. H. sojae is future threatening in soybean production area.

• Textile Coloration and Finishing
• /
• v.19 no.4
• /
• pp.10-17
• /
• 2007

Chitosan(CS) and cellulose acetate(CA) composite films were prepared using formic acid as a cosolvent by casting, solvent evaporating and neutralization method. This study examines if the blending method, which uses formic acid as a cosolvent is efficient in improving the mechanical properties of CS film, especially wet strength and elongation. Formic acid is an effective cosolvent for the blend of CS and CA. Under wet condition, tensile strength and elongation of the composite films were obviously higher than those of the films made from pure CS. FTIR, DSC, and X-ray diffraction showed that the composite films exhibit a high level of compatibility and that strong interaction between the CS and CA was caused by intermolecular hydrogen bonding. The affinity series of composite film to transition metal ions are Cu(II) > Cd(II) > Cr(III). The adsorption of Cu((II) ion was shown to be highly pH sensitive.

• Asian Journal of Business Environment
• /
• v.13 no.4
• /
• pp.19-28
• /
• 2023

Purpose: Emerging markets under industrialization have become increasingly influential over the global natural-resource transactions. However, their average deal completion rates have been relatively low. The international business (IB) literature regards the low rate as evidence of 'double hurdle', the extra disadvantages in doing overseas business for firms from developing countries. Because legitimacy building mitigates liability of foreignness, we argue that an acquirer's environmental responsibility effectively builds legitimacy. Research design, data and methodology: Stakeholders in the host country spread the acquirer's environmental responsibility so that, by raising legitimacy, they may strengthen the link between environmental responsibility and deal completion. Our dataset consists of the 608 cross-border acquisition deals announced by the 196 firms in Brazil, Russia, India, and China over 2008-2019 period. Results: A logit regression result confirms that environmental responsibility increases the likelihood of acquisition deal completion. Also, host-market stakeholders positively moderate the relationship between environmental responsibility and the likelihood of deal completion. Conclusions: Overall, this study contributes to the IB literature by identifying environmental responsibility as a key approach to lowering the double hurdle in internationalization of firms in emerging markets. Any emerging multinationals interested in the foreign, brownfield entries to the natural-resource industries must enhance the environmental responsibility, which turns out extremely important.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.2
• /
• pp.22-31
• /
• 2001

The purpose of this paper is to investigate in resources of natural recreation forest(RNRF) developed both publicly and privately in order to answer the research question: what are the differences in RNRF development between public and private developers. After reviewing the literature, the developer´s decision-making and motivation of investment, and the planning process of natural recreation forest, We constructed the conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed of 625 visitors at 9 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test and logistic regression method. We found that 1) the overall quality of resource elements in RNRF has been development excellent except for the sociocultural element of recreational resources, and public recreation forest have been of higher quality than that fo private development, 20 in bivariate analysis, all the variables on quality of RNRF by public developers have turned out to be better than those of private ones, 3) in multivariate analysis, such variable as valley and water, forest and wildness area, wild life, and landscape have been statistically significant at one percent level, 4) the higher the value of valley and water, the higher the probability of public development, while the higher the value of other variables excluding water and valley, the more likelihood the recreational forest is developed by a private developer, and 5) forest and wildness area has been turned out to be the most important independent variable in contributing to the value of dependent variable. The research results suggest that 1) the differences in the quality of resource elements in RNRF developed by public and private body be considered in the planning and design process in order to develop diverse activities to make use of the resource potential, and 2) considering the resource characteristics of private natural recreation forest and the motivation of private developers, private natural recreation forest will possibly be more dynamic and dynamic attractive areas. It is recommended that the difference in the degree of visitor´s satisfaction between public and private development be examined.

• Applied Biological Chemistry
• /
• v.47 no.1
• /
• pp.17-21
• /
• 2004

This study was investigated the physiological properties of auxin-producing bacteria that have plant growth promoting activity and plant pathogen antagonistic ability. Auxin-producing bacteria were isolated from field soils of Gyeongsan, Korea. Selected strains were identified as a Pseudumonas fulva N21 and a Pantoea agglomerans; K35 by morphological and physiological test, and Biolog (Microlog) system. Auxins were determined by Salkowski in vitro test and mungbean adventitious root induction bioassay. Also produced indole-3-acetic acid (IAA) was identified by TLC. During cell growth, auxin production were highest in their idiophase after log phase and $35^{\circ}C$ at pH 7.5.