• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.36-42
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• 2019

A macroporous Sn thick film as a high capacity negative electrode for a lithium ion secondary battery was prepared by using a chemical etching method using nitric acid for a Sn film having a thickness of $52{\mu}m$. The porous Sn thick film greatly reduced the over-voltage for the alloying reaction with lithium by the increased reaction area. At the same time. The porous structure of active Sn film plays a part in the buffer and reduces the damage by the volume change during cycles. Since the porous Sn thick film electrode does not require the use of the binder and the conductive carbon black, it has substantially larger energy density. As the concentration of nitric acid in etching solution increased, the degree of the etching increased. The etching of the Sn film effectively proceeded with nitric acid of 3 M concentration or more. The porous Sn film could not be recovered because the most of Sn was eluted within 60 seconds by the rapid etching rate in the 5 M nitric acid. In the case of etching with 4 M nitric acid for 60 seconds, the appropriate porous Sn film was formed with 48.9% of weight loss and 40.3% of thickness change during chemical acid etching process. As the degree of etching of Sn film increased, the electrochemical activity and the reversible capacity for the lithium storage of the Sn film electrode were increased. The highest reversible specific capacity of 650 mAh/g was achieved at the etching condition with 4 M nitric acid. The porous Sn film electrode showed better cycle performance than the conventional electrode using a Sn powder.

• Journal of Popular Narrative
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• v.26 no.2
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• pp.251-276
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• 2020

The purpose of this article is to critically read Globalizing Borderlands Studies in Europe and North America to examine trends in border studies conducted so far in Europe and North America and to discuss the expandability and limitations of the narrative. It introduces a variety of case studies covering the borderlands of Europe and North America from ancient to modern times. It consists of a total of 10 chapters, in addition to the introduction chapter to clarify the purpose and definition of the collaboration and the short conclusion chapter on the prospects for the future of borderlands studies. This volume has some important implications for current borderland research in two main respects. First, it can introduce us we the areas and targets that the leading researchers from European and North American academia (usually the United States') have paid attention to. It also examines the current status of borderland research and predicts whether it will be possible to study various border areas where exist in other regions (especially in Asia) based on accumulating academic achievements, as well as the possibility of expansion of so-called 'globalization'. Second, it introduces the borderland as a conceptual space, beyond the border area as a physical space that is commonly thought of when it comes to 'border'. Cases of "conceptual borderlands" can be applied to a number of topics ranging from an individual's identities to the methods of governance, religions, economies, social institutions, families, labor issues, public health services and gender issues. There are, however, also some questions to be noted in the volume: the lack of consistent use of terminology, which can be considered general problems of collaboration studies; the fact that the authors still tend to understand borderlands within the imperialist discourse, perhaps because of their academic background is situated mainly in Europe and North America; the borderlands cases described here as the areas of conflict and struggle only. Nevertheless, the book is of significance in that it suggests a possibility of various borderlands studies and helps us to have better understanding of the current geopolitical situation imposed on the Korean Peninsula, which is located on the borderland between the continental and maritime powers.

• Journal of Environmental Impact Assessment
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• v.32 no.1
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• pp.1-14
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• 2023

When carrying out development projects around Ardeidae breeding habitats, we intend to devise a plan for sustainable coexistence by presenting measures to select and reduce key evaluation items so that conflicts can be prevented in advance at the environmental impact assessment stage. The results of the study are as follows. The main evaluation items are animal and plant items for preservation of Ardeidae breeding habitats and odor and noise items that can evaluate the effects of odors and noise in Ardeidae breeding habitats. First, the scope of the survey in animals and plants categories is not limited to legal guardian species, but includes egrets breeding and feeding grounds corresponding to major species breeding grounds and migratory birds, and preservation measures are established according to the reduction of the area of breeding and feeding grounds. Second, in the odor category, the irradiation period includes the period when the odor generation is the highest from the end of June to the end of July. The odor evaluation standard is based on the complex odor discharge standard, which is a concentration regulation, and the odor concentration felt by humans shall be 2 to 5OU/m³ and the frequency shall be 2% or less. Third, in the noise category, the timing of the survey is measured every month from May to August, including when the sound of egrets and young birds is combined to maximize noise generation. Since the noise of Ardeidae, a bird in summer, occurs only for a certain period of time, measures are taken to reduce noise by securing separation distances, securing buffer green areas, and installing construction rather than installing artificial structures such as soundproof walls. In order for existing Ardeidae breeding sites to maintain an appropriate density of populations and not move populations elsewhere, it is necessary to manage nesting tree and maintain stable habitat quantity and quality.