• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.416-424
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• 2023

Concrete emits a large amount of carbon dioxide throughout its life cycle, and due to the societal demand for carbon dioxide reduction, research on storing carbon dioxide in concrete in the form of minerals is ongoing. In this study, cyanobacteria, which absorb carbon dioxide through photosynthesis and fix it as calcium carbonate, were applied to a porous concrete substrate, and the changes in the properties of the concrete substrate due to their special environmental curing condition were analyzed. The results showed that the calcium carbonate precipitation by the microorganisms was concentrated in the light-exposed surface area, and most of the precipitation occurred in the cement paste part, not in the aggregate. This microbially induced calcium carbonate precipitation enhanced the mechanical performance of the paste and improved the overall compressive strength as the curing age progressed. In addition, the increase in microbial biofilm and calcium carbonate improved the pore structure, which influenced the reduction in water permeability.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.11-20
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• 2010

With the amendment to the Building Act in November of 2005 that offered incentives in terms of floor area ratio and number of stories to apartment buildings adopting the Rahmen structure to facilitate remodeling, the construction industry is paying more attention to PC structures. As connections between PC columns and beams require complex design, it is very difficult to install and remove forms. Since forms made of plywood for such connections are fabricated and installed on site, a significant amount of labor is required, and constructability is low. Furthermore, after concrete casting, the forms are removed in a state in which they cannot be recycled, which leads to a significant amount of construction waste. For this reason, a solution to address such issues needs to be studied. However, many researchers have focused only on the structural performance of PC structures in Korea and elsewhere, ignoring the need for research on the forms used in building PC structure connections. Therefore, this research aims to develop a form that can improve the productivity of PC structure connection construction, and compare it with conventional forms to highlight its contribution to gains in productivity and economic viability.

• Human Ecology Research
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• v.58 no.3
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• pp.279-298
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• 2020

The purpose of this study is to develop home economics educational programs on the theme of 'improving consumer life' for sustainable development. It is a program to enhance the changemaker mindset for responsible production and consumption among the 17 goals of the Sustainable Development Goals(SDGs). The program was developed 8 that to make solar cookers, make household goods from recycled materials, change maker-practice green life, eco-friendly journal 1, plastic warnings, design alternatives for disposable products, change maker-efforts and eco-friendly journal 2. The developed program was validated 3 times by a group of experts and students. This program has the following features. First, the Home Economics Education(HEE) program under the theme of 'Improving consumer life' for sustainable development are carried out at the stage of change-maker education with project-based process. It can improve students' collaboration skills, self-directed skills, communication skills and problem solving skills. Second, eight programs can increase understanding and interest in sustainable development, and learners are interested in social issues. This program can raise learners who play an active role in solving social problems by increasing their interest and interest in the class, free from the form of passive classes. Third, the HEE programs under the theme of 'Improving consumer life' for sustainable development are meaningful in that they are closely related to students' lives and encourage them to practice in their own lives. Fourth, since the program is well-suited to the present time and includes content elements for sustainable development, it can induce changes in learners' perceptions, attitudes and behaviors.

• Journal of the Korea Furniture Society
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• v.20 no.2
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• pp.166-174
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• 2009

Most of the furniture in the past was dedicated to its original use such as storage and accommodation of articles or sitting tools, but the concept of furniture in contemporary indoor spaces is gradually increasing in its meaning while exchanging close impacts with other spatial components. Indeed, in contemporary furniture, a component other than furniture constituting a space would sometimes serve the common roles of furniture or sometimes furniture would include all indoor objects used to make people's living more convenient. This study reviewed the meaning of furniture and changes in its roles in contemporary indoor spaces and summarized the characteristics presenting a few examples. First, in contemporary indoor spaces, furniture as an independent object does not having a meaning any more. The fusion of functions with other components constituting indoor spaces is the most important characteristics in contemporary furniture and it has been already attempted in diverse ways through fusion with buildings surpassing fusion with other pieces of furniture or electric home appliances. Second, the arrangement conforming to the roles required by spaces and diverse forms of attempts are essential. Since furniture is an item the most closely related to human residential life, studies on human behaviors in spaces must precede. The efforts to enhance work efficiencies and used limited spaces more efficiently will be continued and explorations of new forms should be also continued. Third, with regards to manufacturing methods, new technologies should be applied more widely and furniture materials must be diversified through the use of new materials including not only cutting-edge new materials but also all the materials that can be applied to furniture such as conventional natural materials and environment friendly materials that can be recycled.

• Journal of the Korean Electrochemical Society
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• v.5 no.2
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• pp.74-78
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• 2002

Zinc Air battery obtain their energy density advantage over the other batteries by utilizing ambient oxygen as the cathode materials, and reusing cathode as recycled form. And specific capacity of zinc powder is as high as 820 mAh/g. However, if the pore size in cathode is small then the flow rate of air decreased, and as a result of that discharge voltage of batteries becomes low. We focused on resistance and porosity of cathode. So we studied the effects of conducting agents to zinc air batteries performance, capacity, power density, average discharge voltage, resistance. And we also measured porosity of cathode by the ASTM. So we have got optimum contents of conducting agent.

• Resources Recycling
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• v.27 no.2
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• pp.3-10
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• 2018

In this paper, Proposed bonding mechanism that can separate sole and upper for recycle and reuse of parts. It was confirmed that the PVC film with better physical properties than the existing parts was inserted between the sole and the upper. It was confirmed that the separation of the desired form can be induced. As a result of checking the performance of the proposed mechanism, it is confirmed that intentional separation is possible and the separated sole and upper can be recycled or reused.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2325-2332
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• 2012

A series $[C_3Omim]$[X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like $^1H$, $^{13}C$ NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of $CO_2$ for ILs were evaluated at 30 and $50^{\circ}C$ at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for $CO_2$. In general, the $CO_2$ absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol $CO_2$ per mol of IL at $30^{\circ}C$. The most probable mechanism of interaction of $CO_2$ with ILs were investigated using FTIR spectroscopy, $^{13}C$ NMR spectroscopy and result shows that the absorption of $CO_2$ in ether functionalized ILs is a chemical process. The $CO_2$ absorption results and detailed study indicates the predominance of 1:1 mechanism, where the $CO_2$ reacts with one IL to form a carbamic acid. The $CO_2$ absorption capacity of ILs for different anions follows the trend: $BF_4$ < DCA < $PF_6$ < TfO < $Tf_2N$. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of $70^{\circ}C$ or under vacuum and can be used repeatedly.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.05a
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• pp.78-85
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• 2006

In textile industries, waste effluent containing zinc is generated during the manufacture of rayon yarn from the wood pulp or cotton linters. Due to the strict environmental regulations and the presence of toxic metallic and other constituents, the discharge of industrial effluents in the sewage or disposal of solid sludge as landfill is restricted. Before recycling of zinc as zinc sulphate solution to the spinning-bath of the rayon manufacturing plant the zinc sulphate solution must be free from calcium, which is deleterious to the process as gypsum precipitates with the increase in concentration and forms scale in the bath. In the present work an attempt has been made to develop a process following solvent extraction technique using thiophosphinic extractants, Cyanex 272 and 302 modified with isodecanol and diluted in kerosene to recover zinc from rayon effluent. Various process parameters viz. extraction of zinc from different concentration of solution, distribution ratio, selective extraction, O/A ratio on extraction and stripping from the loaded organic, complex formation in the organic phase etc. have been studied to see the feasibility of the process. The extractant Cyanex 302 has been found selective for the recovery of 99.99% of zinc from the effluent above equilibrium pH 3.4 maintaining the O/A ratio of 1/30 leaving all the calcium in the raffinate. It selectively extracted zinc in the form of complex $[R_{2}Zn.3RH]_{org}$ and retained all the calcium in the aqueous raffinate. The zinc from the loaded Cyanex 302 can be stripped with 10% sulphuric acid at even O/A ratio of 10 without affecting the stripping efficiency. The stripped solution thus obtained could be recycled in the spinning bath of the rayon plant. The raffinate obtained after the recovery of zinc could be disposed safely without affacting environment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.2
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• pp.73-78
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• 2009

The decay heat of Cs and Sr contained in a LiCl waste salt, generated from an electrolytic reduction process in pyroprocessing of spent nuclear fuel, has been calculated. The calculation has been carried out under some assumptions that most of the LiCl waste is purified and recycled to main process, and the residual is fabricated to make a waste form. As a result, the decay heat from daughter nuclides such as Ba and Y seems to be maximum 4.6 times higher than that from their parent nuclides such as Cs and Sr. The thermal release from Cs and Sr in the LiCl waste is the maximum around the first one month, so an cooling system operation for some time at the beginning would be suggested to control a rapid increase in the temperature of the LiCl waste salt.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1729-1734
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• 2009

About 40 million automotive vehicles all over the world and 0.55 million in Korea were retired from use annually. Every nation is desperate to decrease environmental pollution by ELVs(End of Life Vehicles) and try to tighten the regulations. Europe passed laws requiring OEMs to increase vehicles' recovery and reuse rate to 95% by 2015 from current 84%. The ferrous parts, 75% of total automobile weight, are almost recycled whereas the remaining 25% of the non-metal -predominantly plastics as well as form, glass and rubber- and the non-ferrous materials -copper, nickel and aluminium- end up in landfills. The recycling status of non-ferrous materials represented by copper and nickel is reviewed and how much the recycling rate will be improved is calculated.