• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.41-49
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• 2002

Resource recovery and recycling of materials and products including polyurethanes are viewed as a necessity in today's society. The problems of recycling polyurethane wastes has major technological, economic and ecological significance because polyurethane itself is relatively expensive and its disposal by burning is also costly. In general, the recycling methods for polyurethane could be classified as mechanical, chemical and physical. In the chemical recycling method, there ate hydrolysis, glycolysis, pyrolysis and aminolysis. This study was carried out glycolysis using new method such as sonication and catalyzed reaction. There are kinds of recycled polyols were produced by current method(glycolysis) but, this study were with catalyzed reaction and sonication as decomposers and the chemical properties were analyzed. The reaction results in the formation of polyester urethane diols and then the OH value which is determined by the quantity of diol used for the glycolysis conditions. The glycolysis rates by sonication and catalyzed reaction for the various glycols, increased as: PPG

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.668-672
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• 2010

In wireless sensor networks, a fault-tolerant scheme that detects the failure of sensor nodes and improves the reliability of collected information must be considered. Resource-constraint sensor nodes expose vulnerability and cannot use existing checkpointing schemes that do not consider a feature of sensor networks. In this paper, we propose a fault-tolerant scheme for clustering routing protocols that support the recovery of a head node.

• Journal of Korea Foundry Society
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• v.2 no.3
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• pp.16-24
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• 1982

For the purpose of development of domestic carburizer, when the basicity of ash in carburizer was changed from $Na_2O/Al_2O_3+SiO_2$ ; 0.06 to $Na_2O/Al_2O_3+SiO_2$ ; 0,196wt%, using $Na_2O$ as flux for domestic graphite resource (Bong Myung armorphous graphite), carburizing efficiency was improved as basicity increased, optimum basicity value was $Na_2O/Al_2O_3+SiO_2$ ; 0.151. This means that $Na_2O$ contributed to lower viscosity of slag and raise occurence probability of specific reaction surface between molten iron and carburizer. The experiment of effect of general characteristics offecting carburizing ability of this carburizer was performed, the result is that 10/30 mesh was optimum size of the carburizer and as carbon equivalent of molten iron was higher, carburizing ratio was lowered, but when si concentration was below 1.8% in general cast iron melting region, recovery showed 75-85%. As agitation rate of molten iron and temperature interval were higher, Carburizing ratio was increased and showed max, 94%. Desulfurizing phenomena of molten iron by $Na_2O$ in carburizer didn't appear.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.653-658
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• 2012

There is an increasing interest in the use of electrochemical methods for the food waste treatment. The technologies using the electrochemical method provide ideal tools for approaching industrial and food wastes problems. Unlike other chemical treatments, the electrochemical systems do not make the volume of the secondary waste increase. The electrochemical methods can be operated with electrochemical apparatus and inorganic agent allow selective separation and recovery and even quieter than others. This study concerns design factors, electrode construction and wastewater treatment process of the electrochemical apparatus. The experiment of color, COD and BOD removal is much effective in using electrochemical method with ultrasonication and ozonation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1046-1054
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• 2002

In this paper, we propose a subnetwork-based segment restoration scheme to reduce the restoration time and restoration resources. And we compare and analyze the restoration performance according to the size of divided subnetworks. Segment restoration is based on network partitioning where a large network is divided into several small subnetworks and the end-to-end data path is divided into multiple segments according to the subnetworks. In segment restoration, the link/node failure is restored by segment instead of end-to-end path. Because most faults are restored within the subnetwork, the restoration performance can be improved. From the simulation analysis, we verified that the proposed segment restoration has advantage of restoration time and backup resource utilization.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.42-51
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• 2013

Climate changes have become the major issue for the sustainable society and the various regulation has been established for promoting low carbon and green growth in Korea. The paper industry as a large comsumer of energy is forced to cope with these regulation. In this study, the various examples were investigated for providing the basic schemes to develop environmental management strategies of Korean paper industry. The various cases to follow carbon economic were introduced and were categorized into five ways, for example, the carbon capture projects such as reforestation, the increasing the process efficiency, the resource recovery form process waste, the cogeneration systems, the application of non-woody biomass.

• Resources Recycling
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• v.10 no.6
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• pp.15-21
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• 2001

Shape-controlled copper oxides have been recovered from copper-containing waste etchant by neutralization with alkalihydroxide. Large amount of copper-containing waste etchant is generated from Printed Circuit Board industry. In an environmental and economic point of view, retrieve of the valuable natural resource from the waste is important. In recycling process of copper oxide from the waste etchant, reaction temperature controls shapes and sizes of the products. Copper oxide recovered below reaction temperature $40^{\circ}C$ was of a needle shape, while copper oxide comes in a platy shape above $40 ^{\circ}C$ . Physical properties of samples have been characterized using SEM, XRD, TGA and Atomic absorption spectroscopy.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.247-250
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• 2009

Awareness of resource conservation and pollution prevention has been continually increasing. The proven benefits from CFRP's unique combination of light weight and high strength compare to conventional material is well suited for minimizing fuel consumption during vehicle in particular rail operation. Responding the awareness, this work intends to study CFRP's recycling method that is not only technical performance but also environmental view point. According to prior work of technical performance test, this work aims at quantifying the footprint of energy and GHG derived from the two appreciated performance of pyrolysis and acids recycling methods. The streamline LCA is the concept for systematic assessment. The boundary is scoped at the recycling activity, consequently, the data in and out from the specific target activity are obtained under the gate to gate data collection. Its function is recovery carbon fiber. To count and compare function, functional unit is set at 60% of recycling rate. Korea database is mainly source for acquiring the footprint of both. The numerical results presented that the energy footprint of acids and pyrolysis is 164.95 and 1,199.88 MJ-eq., respectively. Meantime, the GHG footprint of is 1,196.22 and 5,916.08 g CO2 eq. for acids and pyrolysis. In summary, the acids recycling method is, in regarding the environmental performance, better than pyrolysis recycling method.

• Fire Science and Engineering
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• v.32 no.1
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• pp.116-121
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• 2018

This study aimed to provide help to seeking a preventive method of intervention in firefighter's depression by investigating empowerment and family function level of firefighter's on their depression. For this, the study conducted purposive sampling survey among 351 firefighters at Gyeonggi area. As a result of the research, all of empowerment and family function had a significant effect on depression of firefighters. Based on these findings, the study demonstrated the potential for applying each individual's empowerment as an internal resource for their prevention of mental health. The study suggested that diverse counter measures are needed to boost family bond and family functionality of firefighters, and also proposed positive adoption and assistance for preventive and effective implementation of 'work and life balance' policy to derive the recovery of healthiness of families.

• Environmental Engineering Research
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• v.24 no.4
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• pp.618-629
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• 2019

Along with growing population and economic development, increasing waste generation rates in developing countries have become a major issue related to the negative impacts of waste management on the environment. Currently, the business-as-usual waste management practices in Myanmar are largely affecting the environment and public health. Therefore, this study developed an alternative approach to waste management for reducing the environmental impacts in Myanmar by highlighting the greenhouse gas (GHG) emissions from business-as-usual practices and three proposed scenarios during 2018-2025. The calculation methods of the Intergovernmental Panel on Climate Change and Institute for Global Environmental Strategies were used for estimating the GHG emissions from waste management. It was estimated that the current waste management sector generated approximately 2,000 gigagrams of CO₂-eq per year in 2018, trending around 3,350 Gg of CO₂-eq per year in 2025. It was also observed that out of the proposed scenarios, Scenario-2 significantly minimized the environmental impacts, with the lowest GHG emissions and highest waste resource recovery. Moreover, the GHG emissions from business-as-usual practices could be reduced by 50% by this scenario during 2018-2025. The target of the similar scenario could be achieved if the local government could efficiently implement waste management in the future.