• 공업화학
• /
• 제23권2호
• /
• pp.195-203
• /
• 2012

폐 LCD유리의 재활용 방안은 평판 디스플레이용 폐 LCD판넬의 전체 재활용 공정의 확립을 위한 중심요건이다. 본 연구는 폐 LCD유리를 보온단열재, 흡음차음제, 토목용 경량골재 또는 수처리용 담체 등의 원료로 재활용하기 위한 발포공정의 기초공정으로서 폐 LCD유리의 분쇄특성, 적절한 탄소발포제의 선정, 유가물 회수를 위한 산침출 후 잔유된 유리질의 물성 및 이들의 발포화의 문제점을 조사하였다. 폐 LCD유리의 분쇄공정을 통해 발포용 원료로 사용가능한 미분화가 가능하였으며, 고융점을 갖는 LCD 유리의 발포화를 위해서는 결정성 천연흑연이 적절하였으며, 산 침출 후 잔사인 슬러지 상태의 폐유리성분도 발포체의 원료로 재활용될 수 있음을 확인하였다.

• 아시안잔디학회지
• /
• 제4권1호
• /
• pp.42-48
• /
• 1990

Experiments were conducted to investigate the soil freezing depth and pattern with freezing measuring instruments during 1988-l989 winter season in Kangwon province. Freezing measuring instrument was made with acrylic pipes which were consisted of inner and outer parts. Inner pipe was filled with 0.01 % methylene blue solution and rubber hose to protect pipe breakdown by solution freezing. Freezing measurements were carried out by observing discoloration of methylene blue solution. Moisture content of evergreen trees and ground cover plants was also examined in the winter season. The observed results are as follows: 1.In the land of I OOM above sea level, soil freezing depth became deeper as the sum of Accumulated degree-days of temperature below 0˚C(0˚C . day) increased: Soil freezing depth was 30-40cm at l00˚C, 42-43cm at 150˚C, and 47cm at 200˚C day 2.Soil freezing with vinyl mulching was less developed by l3cm at l00˚C with sum of subzero temperature, by l7cm at 200˚C than that of the bare ground. Soil of rich hulls mulching with 4Ocm was not frozen until soil freezing at the bare ground was developed to 25cm depth. 3.Cashmeron mulching was more effective than felt mulching in the heat insulation of soil. 4.Thawing of soil was done from the lowest part of the frozen in the ground to upward in the beginning and after that it was done from the surface of frozen soil to downward. Finally thawing was completed at the middle of frozen soil.

• 한국건축친환경설비학회 논문집
• /
• 제12권6호
• /
• pp.531-542
• /
• 2018

Building energy demands have highly risen in modern society; thus, It is necessary to reduce building energy demands especially commercial buildings adopting a curtain wall architecture. Curtain wall architectures have a high ratio of windows which is a vulnerable in heat insulations as cladding. In order to complement insulation performance of windows in these buildings, there are various methods adopted often such as installing blinds, wing wall and films. There are two suggestions of this paper. 1) WWR (Window-to-Wall Ratio) makes a impaction of energy demands in buildings. 2) Another one is an efficiency of blind systems which are installed in buildings in order to reduce cooling demands. It is also critical to make fundamental model for low-energy building construction by processing a lot of simulation As a result by this study, 1) an external blind system is more useful for reducing cooling energy demands rather than an internal blind system. 2) Buildings which have a large window require more amount of cooling demands. In case of WWR 45%, it needs more cooling energy rather than WWR 15% model's 3) Adopting blind system would reduce energy demands. WWR 45% model with external blind systems reduces about 4% of cooling energy demands compared to same model without any blind systems.4) it is necessary to study an efficiency of blind systems combined with renewable energy and it will be possible to reduce more energy demand in building significantly.

• 대한건축학회논문집:계획계
• /
• 제33권12호
• /
• pp.53-63
• /
• 2017

The purpose of this study is to present an integrated analysis for energy use and its patterns as vertical locations of the dwelling units in apartment buildings which are located in an urban area and constructed by a renowned contractor. In order to enhance the effectiveness of the method, the original data of electricity, water, and gas bills which directly reflect the energy use are sorted and analyzed into several groups as vertical locations in each building. And also, by use of comparing and contrasting the data on a monthly and yearly basis, the accuracy of analyses for seasonal energy use and its patterns is strengthened. Comparative analyses used in this study describe the results that vertical locations of dwelling units do not have much influence on electricity and water usage, but are closely related with gas usage for a heating season. According to the analysis of gas usage, the units on the ground and right above pilotis need enhancement in the insulations for heating to mitigate energy loss. Also, the analysis for the middle floor units in each group describe the fact that the gas usage of the units on the ground is consumes 1.5 times greater than that of the typical floors. Therefore, enhanced insulation strategies need to be considered against the adverse condition that the heat loss increases as the wall facing the outside air increases or as the wind velocity increases through the pilotis.

• 대한건축학회논문집:계획계
• /
• 제34권2호
• /
• pp.41-48
• /
• 2018

This study is expected to provide some basic data on how to apply more economical and efficient eco-friendly factors to reduce the carbon emissions. It has been scrutinized and analyzed the environmental factors of passive eco-friendly elements along with active eco-friendly elements as more efficient factors for energy conservation based on the case of a newly constructed broadcasting building with the green building certification in Sangam-dong DMC area. The first analysis was the energy consumption trends in Korea and the necessity of energy saving. Secondly, it was examined the energy consumption in the current status of the broadcasting building. Thirdly, it was looked into the correlation between the eco-friendly design application factors applied to the broadcasting building and the energy consumption types. As a result of the analysis, the application of fan and feed pump inverter along with ventilation system of waste heat recovery ventilation system were more meaningful in accordance with the economic feasibility of broadcasting buildings rather than economical effect of passive elements such as rooftop garden, reinforcement of building insulation. Also, the application of lighting control had the economical feasibility. Therefore, when it is intended to change the green building certification energy related evaluation items of the similar broadcasting building types, it is necessary to change the direction of adding weight to the more economical active element items in the future.

• 한국폐기물자원순환학회지
• /
• 제35권8호
• /
• pp.692-700
• /
• 2018

In this study, the results of PBDEs and HBCDs of the products and waste that contain BFRs such as domestic electronic products, automobiles and textile products were compared with international management standards, and their excess rates were calculated. Deca-BDE was detected among the PBDEs in TV rear cover plastics, car seats, automotive interior plastics, and automobile shredding residues of products and waste containing BFRs. The comparison with Basel Convention management standards (1,000 mg/kg) for PBDE-containing wastes (4 types in total) shows that the excess rate of all samples was less than 1.5%. The estimated excess rate compared to the EU and Basel convention management standards (1,000 mg/kg) for PBDEs (4 species + deca-BDE) and TV rear cover plastics was 37.5% (30 of 80 samples exceeded the standards). The estimated excess rate compared to the Basel convention management standards (1,000 mg/kg) for HBCD, building materials products and waste was 15.7% (17 of 108 samples exceeded the standards). In the case of PBDEs, it is necessary to remove only the rear cover of CRT TV among the electric and electronic products and treat it in the flame retardant treatment facility to improve the recycling collection system. In the case of HBCD, it is necessary to appropriately dispose of the recycled materials, heat insulation materials, TV plastics, and styrofoam in marine fishery among construction materials and restrict the use as recycled raw materials.

• 한국기계가공학회지
• /
• 제20권6호
• /
• pp.33-43
• /
• 2021

A60 class bulkhead penetration piece is a fire resistance system installed on a bulkhead compartment to protect lives and to prevent flame diffusion in a fire accident on a ship and offshore plant. This study focuses on the approximate optimization of the fire resistance design of the A60 class bulkhead penetration piece using a multi-island genetic algorithm. Transient heat transfer analysis was performed to evaluate the fire resistance design of the A60 class bulkhead penetration piece. For approximate optimization, the bulkhead penetration piece length, diameter, material type, and insulation density were considered discrete design variables; moreover, temperature, cost, and productivity were considered constraint functions. The approximate optimum design problem based on the meta-model was formulated by determining the discrete design variables by minimizing the weight of the A60 class bulkhead penetration piece subject to the constraint functions. The meta-models used for the approximate optimization were the Kriging model, response surface method, and radial basis function-based neural network. The results from the approximate optimization were compared to the actual results of the analysis to determine approximate accuracy. We conclude that the radial basis function-based neural network among the meta-models used in the approximate optimization generates the most accurate optimum design results for the fire resistance design of the A60 class bulkhead penetration piece.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2022년도 춘계학술대회
• /
• pp.314-316
• /
• 2022

수도계량기는 사용자가 사용하는 물의 양을 계측하는 기기로 계량안정성 관리가 필요하다. 하지만 겨울철 한파로 인해 계량기 내부의 물이 얼음으로 상변화하며 약 9%의 체적이 커지게 되며 계량기의 파손이 발생된다. 기존 동파방지용 수도미터 동파방지 기술은 크게 세 가지로 보호통 내부에 열을 공급하는 방법, 단열을 위한 수도미터 외부 보호방법, 수도계량기에 동파방지 장치를 설치하는 방법으로 나뉜다. 기술개발 제품의 상용화를 위하여 구조를 최대한 변형시키지 않으며 외부전원이 필요하지 않은 기술을 개발하는데 목적이 있다. 따라서, 영하의 온도에서 수도계량기에 가해지는 내부압력을 해석하여 동파 취약부위를 확인하고 파손을 방지하기 위해 내부 압력을 감소시킬 수 있는 동파방지 효과가 우수한 수도계량기를 개발하고자 한다.

• 한국안전학회지
• /
• 제38권1호
• /
• pp.25-33
• /
• 2023

In this study, we determined the failure rate and fire status of electric motors widely used in domestic and industrial devices and analyzed the associated fire risks by identifying the electrical and temperature characteristics of electric motors under the normal and restrained operation modes in industrial sites and laboratories. A 2.2kW motor used for driving a conveyor during the vulcanization process in a rubber product manufacturing plant was employed as the study object and was exposed to a high- temperature environment as this motor is widely used in industrial sites. The current amplitude was 4.45-4.50 A during normal operation and 38.2-41.5 A during restrained operation due to the pinching of products and semi-finished products (i.e., 8.5 times higher than that during normal operation). The leakage current amplitude was 0.33 mA during both operation modes. The temperature of the workplace in summer was 42.38℃, indicating a poor environment for the installed motor. In the laboratory, the current and temperature of the coil inside a 3.7kW motor were measured under the restrained operation mode as performing measurements of the coil inside the motor in industrial sites is challenging. The current amplitude during normal operation was 3.5 A, whereas that during restrained operation for 30 s was 51.7-58.6 A, which is 14.8-16.7 times higher than that of normal operation. Moreover, the temperature of the motor coil increased from 22.9℃ to 101℃. Based on the experimental data, we derived the temperature increase formula according to the restrained operation time by performing a regression analysis and verified the time at which the temperature exceeded the stipulated limit for the insulation grade. The findings presented in this paper can be utilized to establish fire-prevention measures and perform safety management of motors of the same type or with a similar capacity.

• Structural Engineering and Mechanics
• /
• 제84권3호
• /
• pp.393-411
• /
• 2022

A high-performance reactive powder concrete (RPC) has been readied alongside river sand, with 1.25 mm particle size when under the condition of 80C steam curing. As a heat and sound insulation, expanded perlite aggregate (EPA) provides economic advantages in building. Concrete containing EPA is examined in terms of cement types (CEM II 32.5R and CEM I 42.5R), doses (0, 2%, 4% and 6%) as well as replacement rates in this research study. The compressive and density of concrete were used in the testing. At the end of the 28-day period, destructive and nondestructive tests were performed on cube specimens of 150 mm150 mm150 mm. The concrete density is not decreased with the addition of more perlite (from 45 to 60 percent), since the enlarged perlite has a very low barrier to crushing. To get a homogenous and fluid concrete mix, longer mixing times for all the mix components are necessary due to the higher amount of perlite. As a result, it is not suggested to use greater volumes of this aggregate in RPC. In the presence of de-icing salt, the lightweight RPC exhibits excellent freeze-thaw resistance (mass is less than 0.2 kg/m²). The addition of perlite strengthens the aggregate-matrix contact, but there is no apparent ITZ. An increased compressive strength was seen in concretes containing expanded perlite powder and steel fibers with good performance.