• Resources Recycling
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• v.27 no.2
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• pp.11-23
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• 2018

The need for remanufacturing automotive parts is required due to the depletion of resources, rising raw material prices and strengthening environmental regulations. For remanufacturing, stable supply and demand of core must be accompanied. At present, remanufacturing companies collect cores through various routes, but the recovery rate of cores from the End-of-Life Vehicles is low. If we can systematically collect cores from hundreds of thousands of ELVs that were generated each year, the recovery rate of the core for remanufacturing will be further improved. Therefore, in this paper, we tried to establish a classification system for the ELV as a method for collecting the cores from the ELV. First, we selected the elements affecting the classification and determined the scope for the evaluation. The final rating classification is established by calculating the weights among the influence elements. Finally, through the case study, the dismantling grade of the actual ELV was evaluated to derive the second grade.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.141-149
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• 2013

This paper presents a scheduling technique that reflects various constraints in remodeling project of inhabited condition. The remodeling project of inhabited condition is required more detailed planning and control due to claims by noise, vibration, dust, smells, limited lift capacity, and limited temporary stock area. Because of the constraints, complexity in scheduling is increased and earlier completion is required to reduce the possibility of safety and environment accidents. Especially, in case of inhabited condition, the scheduling should be linked day-time/night-time/weekend work. This paper proposes a structured scheduling technique to incorporate those constraints in remodeling of inhabited condition. This scheduling technique considers not only remodeling process but also dismantling, newly-construction, and residents movement. Process expression method using MS-Project also presented to keep connectivity with existing scheduling system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.121-127
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• 2010

An experimental study of composite beam with perforated fiber reinforced polymer(FRP) plank as a permanent formwork and the tensile reinforcement was performed. A combined formwork and reinforcement system can facilitate rapid construction of concrete members since no conventional formwork is needed, which requires time consuming assembly and dismantling. In order for a smooth FRP plank to act compositely with the concrete, the surface of the FRP needs to be treated to increase its bond properties. Aggregates were bonded to the FRP plank using a commercially available epoxy and perforated web of plank. No additional flexural or shear reinforcement was provided in the beams. For comparison, two control specimens were tested. One control had no perforated hole in the web of FRP plank and the other had internal steel reinforcing bars instead of the FRP plank. The beams were loaded by central patch load to their ultimate capacity. This study demonstrates that the perforated FRP plank has the potential to serve as a permanent formwork and reinforcing for concrete beam.

• Resources Recycling
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• v.22 no.4
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• pp.70-80
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• 2013

Waste refrigerator is the most large amount of item being recycled and the recycling process is the most complicated in WEEE (Waste Electrical and Electronic Equipment) because refrigerator is biggest product and consists of various parts and materials such as ferrous, non-ferrous, and plastics. Recently, recycling process of waste refrigerator has been being more complex since large capacity 2 door refrigerators and standing Kimchi refrigerators with various material are distributed on custom market. In addition, recycling of valuable resource from waste refrigerator is mandatory by WEEEs recycling legislation; therefore, high efficiency recycling enough for economic and environment-friendly recovery of valuable resource through present technical situation analysis and comparison of recycling technologies of waste refrigerator with advanced country.

• Steel and Composite Structures
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• v.44 no.1
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• pp.33-47
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• 2022

This paper presents a finite element model for predicting the monotonic behaviour of bolted endplate joints connecting steel-concrete composite walls and steel beams. The demountable Hollo-bolts are utilised to facilitate the quick installation and dismantling for replacement and reuse. In the developed model, material and geometric nonlinearities were included. The accuracy of the developed model was assessed by comparing the numerical results with previous experimental tests on hollow/composite column-to-steel beam joints that incorporated endplates and Hollo-bolts. In particular, the Hollo-bolts were modelled with the expanded sleeves involved, and different material properties of the Hollo-bolt shank and sleeves were considered based on the information provided by the manufacture. The developed models, therefore, can be applied in the present study to simulate the wall-to-beam joints with similar structural components and characteristics. Based on the validated model, the authors herein compared the behaviour of wall-to-beam joints of two commonly utilised composite walling systems (Case 1: flat steel plates with headed studs; Case 2: lipped channel section with partition plates). Considering the ease of manufacturing, onsite erection and the pertinent costs, composite walling system with flat steel plates and conventional headed studs (Case 1) was the focus of present study. Specifically, additional headed studs were pre-welded inside the front wall plates to enhance the joint performance. On this basis, a series of parametric studies were conducted to assess the influences of five design parameters on the behaviour of bolted endplate wall-to-beam joints. The initial stiffness, plastic moment capacity, as well as the rotational capacity of the composite wall-to-beam joints based on the numerical analysis were further compared with the current design provision.

• Journal of the Korean GEO-environmental Society
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• v.23 no.3
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• pp.5-13
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• 2022

In this study a test was conducted to identify weak section using 100kJ class rock energy to find out the protection performance of rockfall prevention fences in Korea. Performance rating of the rockfall protection fences is very low (48~61kJ) compared to that of foreign countries and it is necessary to determine whether it can function properly if high rock energy is generated. Furthermore, a reinforcing technology that can improve to 100kJ energy on the existing rockfall protection fences should be developed. Therefore, this study confirmed the protection performance using 100kJ rock energy in the existing rockfall protection fence system (for national road, for highway) and identified weak section of post, wire ropes and nets. Furthermore, it will be used as basic data for developing 100kJ class reinforcement technology without dismantling the existing rockfall protection fence (48-61kJ).

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.402-408
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• 2016

Master packaging system consists of an inner individual package and secondary outer package. During the stages of chilled transport and distribution, the combination of primary individual package and secondary package was used to maintain a modified atmosphere for shiitake mushrooms. During the retail stage at higher temperature ($25^{\circ}C$), the primary individual package was exposed to display conditions after dismantling of the secondary packaging. The master packaging system was constructed to contain eight individual $30-{\mu}m$ thick polypropylene film bags of 500 g shiitake mushrooms inside a $40-{\mu}m$ low-density polyethylene bag. Carbon dioxide absorbent material [$Ca(OH)_2$] and/or moisture absorbent (superabsorbent polymer) were designed in their required amounts based on respiration characteristics and then applied to the outer secondary packaging in sachet form. Gas concentration of the packaging, temperature, and humidity were monitored throughout transport and storage. The quality of shiitake mushrooms was measured at the retail stage to determine the packaging effect. During the distribution stage of 108 h, $O_2$ and $CO_2$ concentrations in the master packaging system were maintained at 9~11% and 1~4% in the inner packaging, respectively, which are good for quality preservation. Compared to the control, the master packaging with $CO_2$ and/or moisture absorbents improved mushroom preservation and particularly reduced decay.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.135-145
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• 2016

In Korea, a series of noise-reduced aluminum forms are being recently used in apartment housing construction. However, their complicated and time-consuming work processes, and the noise which is still generated due to the inherent property of aluminum when especially installing and dismantling them have been pointed out as a problem to be certainly solved for increasing their practical use in construction sites. The primary objectives of this study are proposing an optimal conceptual design of a newly designed noise-reduced aluminum form and verifying the technical feasibility by conducting a working mock-up drive experiment. Thus, conventional noise-reduced aluminum forms have been analyzed and three conceptual designs of a newly noise-reduced aluminum forms have been deducted. AHP has been applied to a survey data collected by interviewing field experts. A trade-off analysis results have shown that 'Noise-reduced System Aluminum Form with a Drop-down Floor Post and Adaptive Beam' the highest weights of safety(0.52), work convenience(0.54) and thus selected. The suggested conceptual design in this study improved problems of conventional system aluminum forms. It is also expected that the suggested design will be used as a reliable guideline for the actual development of an aluminum form that ensures noise-reduce, work convenience and labor safety.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.848-855
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• 2003

During concrete placement, the partially distributed load due to the concrete placement paths creates the lateral force in the connection parts of the shore. In order to restrain this lateral force, the nails must be used in the upper and lower connection parts of shores. But, for the convenience of the construction and dismantling of the shores, the workers hardly use the nails. In this case, the connections of shore cannot resist the shear force and rotation. And this situation may cause the collapse of form-shore system. Therefore, contact and spring models for the connection analysis of the form-shore systems are required. If we take into account this construction situation, we need to understand the effects of shear and rotation stiffness according to the several types of connection parts in shores as a case study. This study evaluates the shear and rotation stiffness of the connection parts of shores according to the variations of the lengths, numbers and positions of nails, and then presents the experimental results depending on the end conditions of shores. And, these results can be used as a spring model and critical load evaluation data for the connection analysis of form-shore system.

• Resources Recycling
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• v.29 no.4
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• pp.15-30
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• 2020

Recently, it is increasing a amount of installed solar-cell rapidly, and end-of-life photovoltaic(ELP) modules are generated in according to the reduction of cell efficiency largely. Recycling of ELP modules are begun at an advanced nation already, but there are bring about environmental contamination and resource recovery problems owing to not treated ELP modules because of economic cost completely. First of all, there were researched basic study for treatment conditions of used solar cell inspection, dismantling of aluminum frame, crushing / grinding & separation of tempered glass, removal of back sheet & EVA film, leaching & precipitation recovery of valuable metals and treatment of waste water. Therefore, we establish optimum conditions through carried out of designed apparatus, installation of equipment, test operation & trouble shooting in scale of 1ton/day pilot plant test. Following to economic review, it does have the economic efficiency until to the case of tempered glass recovery, but does not have the economic value in case of total processes until to recover the valuable metals. However, there are guaranteed economic value if we are gained a large amount of the expenses through EPR supported system. It was confirmed the commercialized possibility of ELP modules recycling if there were established on the collecting ELP modules, reusing criteria, economical technology, enactment of directives and enforcement of EPR supported system efficiently.