Currently, a technique to subdivide the process refining is introduced, can be divided into the steel slag. In this study, Free-CaO in the electric arc furnace slag by the ethylene glycol method for the quantitative analysis for the expansion to proceed with construction materials.

As environmental concerns including climate change drive the strong regulations for car exhaust emissions, electric vehicles attract the public eye. The purpose of this study is to identify rural areas vulnerable for charging infrastructures based on the spatial distributions of the current gas stations and provide the target dissemination rates for promoting electric cars. In addition, we develop various scenarios for finding optimal way to expand the charging infrastructures through the administrative districts data including 11,677 gas stations, the number of whole national gas stations. Gas stations for charging infrastructures are randomly selected using the Monte Carlo Simulation (MCS) method. Evaluation criteria for vulnerability assessment include five considering the characteristic of rural areas. The optimal penetration rate is determined to 21% in rural areas considering dissemination efficiency. To reduce the vulnerability, the charging systems should be strategically installed in rural areas considering geographical characteristics and regional EV demands.

CO2 emitted from building materials and construction materials industry reaches about 67 million tons, which occupy about 30% of CO2 emitted from the construction field. Controls on the use of consumed fossil fuels and reduction of emission gases are essential for the reduction of CO2 in the construction area as we reduce the second and third curing to emit CO2 in the construction materials industry. Accordingly, this study applied the low energy curing admixture (hereinafter “LA”) to the extruded panels to observe the physical properties, depending on the mixing amount of fiber, type of fiber and mixing ratio of fiber. The type of fiber did not appear to be a main factor to affect strength, while the LA mixing ratio and mixing amount of fiber appeared to be major factors to affect strength. Especially, the highest strength was developed when the LA mixing ratio was 40%, whereas the test object with the mixing ratio of 50% resulted in the decrease of strength. In addition, it appeared that the mixing ratio of fiber greatly affected flexural strength and strength increased as the mixing ratio increased.

This laboratory study showed the performance evaluations of a improved C12A7 based mineral accelerator (I-CA) by both mortar and shotcrete tests. Performance of I-CA as a shotcrete accelerator was excellent by KCI-SC-102, which is a Korean specifications of shotcrete accelerator. In addition, I-CA showed equal qualities to the setting time and the compressive strength when compared those of the existing C12A7 based mineral accelerator (CA). The I-CA was manufactured with 40wt.% of electric arc furnace reducing slag, 24wt.% of lime, and 36wt.% of bauxite, indicating that the commercialization of I-CA contributed to recycle electric arc furnace reducing slag and to reduce the manufacturing cost of C12A7 based mineral accelerator due to the use a cheap raw material(electric arc furnace reducing slag), and to reduce the greenhouse gas emission due to the reductions in usage of lime and bauxite.

전기화재의 주된 원인은 단락, 과부하·과전류, 누전 및 접촉 불량 사고로 크게 구분되고, 전기화재는 상기의 1차적인 원인보다는 이들 사고에서 동반되는 전기아크(electric arc)에 의한 주변 가연물질로 확대되는 2차적인 영향에 의한 화재가 대부분이다. 본 논문에서는 저압배선계통을 이용하는 가정이나 산업현장에서 주로 발생하는 전기화재의 주요 원인인 아크 사고를 감지하지 못하는 기존 과부하겸용 누전차단기(RCD)의 문제점을 해결하기 위하여, 첨단 마이크로프로세서를 이용한 고속 고정밀의 아크 펄스 사고 감지용 마이크로프로세서 제어기를 제안한다. 또한 아크 펄스 사고 시뮬레이터를 이용한 실측 특성분석을 통하여 그 성능을 입증하고자 한다. 제안한 마이크로프로세서 제어기는 구조와 제어알고리즘 기법이 간단하여 소형·경량으로 설계 및 제작이 가능하고, 이에 따른 제작비용 감소와 설치 방법이 간단한 장점을 가진다.

Carbon dioxide generated from construction materials and construction material industry among the fields ofconstruction is approximately 67million tons. It is about 30% of the carbon dioxide generated in the fields of construction.In order to reduce carbon dioxide in the fields of construction, it is necessary to control the use of fossil fuel consumedand decrease carbon emission by reducing the secondary and tertiary curing generating carbon dioxide in constructionmaterial industry. Therefore, this study produced an extrusion panel by using cement as the base materials and substitutingbinding materials up to 40% to analyze strength characteristics. According to the results of strength characteristics bythe replacement binder (Low energy curing Admixture) showed an apparent active strength improvement. In particular,specimens substituting binder as 45% indicated the greatest strength improvement. When binding materials was used withsubstitution, it showed strength characteristics similar or higher than specimens made from tertiary autoclave curing assecondary steam curing.

Based on the study of development of motor-driven electric tool, it was found that the use of the mechanism developed was effective to bolt unit modules. On the other hand, an additional study is required such as torque of the tool.

In this study, a new foundation in a spiral type was developed for the solar electric power system. Based on the structural analysis considering the existing design code, the superiority of the new foundation system was verified via a finite element analysis on the structural stability and safety.

In this study, an equivalent circuit model of CNT-filled cement composites is proposed. Both the polarization effect of electrode/composite interface and the complex resistance effect due to dielectric property of CNT cement composite are considered in the proposed model. Effective of the proposed model will be experimentally validated.

본 연구는 산업부산물을 아스팔트 혼합물 포장에 활용하고 천연골재를 대체하기 위한 연구로써 전기로 산화 슬래그를 이용한 아스팔트 혼합물의 물리적 성능과 내구성능을 분석하였으며, 현장 적용성을 분석하기 위하여 시험시공을 실시하였다. 아스팔트 혼합물의 내구성능을 평가하기 위해 아스팔트 혼합물의 최적 배합을 도출하여 평가하였다. 마샬안정도 등 실내시험결과 전기로 산화 슬래그 혼합물이 일반 혼합물보다 높은 강도를 나타내었다. 수분 민감도 실험에서도 일반 혼합물과 동등한 저항성을 나타냈다.시험시공을 통한 현장 적용성은 기존 천연골재 아스팔트 혼합물과 동일하였으며, 미끄럼저항성능이 더 우수한 것으로 확인되었다.

본 연구에서는 MEMS 기반 3축 가속도 센서 모듈을 제작하여 성능 시험을 수행하였고, 지진 모니터링 시스템을 구성하였다. 3축 가속도 센서 모듈의 성능 향상을 위하여 데이터 수집장치를 24bit ADC (Analog to Digital Converter)가 내장된 NI-9239를 사용하였고, 잡음을 줄이기 위해 100Hz LPF (Low Pass Filter)를 통과시킨 데이터를 사용하였다. 또한 지진 모니터링 소프트웨어를 개발하여 구조물에 유의한 진동을 감지하는데 초점을 맞추었다. 진동을 감지하기 위한 방법으로 각 축의 가속도 크기 뿐만 아니라 3축 가속도의 벡터 합을 구하여 이 벡터 합이 미리 설정한 값을 초과할 때의 수치를 별도로 표시하고 이를 파일로 저장하는 알고리즘을 사용하였다.

Apple juices were sterilized by continuous pulsed electric field (PEF) treatments of pulse width of 25 μs at electric field intensity of 20.0 kV/cm, and with the varied pulse frequencies of 35 Hz (40 kJ/L), 55 Hz (70 kJ/L), 72 Hz (100 kJ/L) and 85 Hz (130 kJ/L). The PEF treatments of apple juice reduced the microbial counts from 5.3 log CFU/mL of initial state to 3.0 log CFU/mL after PEF treatment at energy density of 130 kJ/L. Also yeast and fungi after PEF treatments were reduced from 5.3 log CFU/mL to 3.0 log CFU/mL and Escherichia coli were from 5.3 log CFU/mL of initial state to 4.7 log CFU/mL to <101 CFU/mL. The soluble solids and free sugars did not significantly differ (p<0.05) depending on conditions of PEF treatment. The total phenolic contents and antioxidant activity such as the DPPH and ferric reducing antioxidant power (FRAP) by PEF treatments were significantly partly reduced, but the PEF-reduced value came in smaller uantities than the heat treatment at 65℃. The iterative PEF treatments with pulse width of 25 μs and pulse frequency of 85 Hz at electric field intensity of 20.0 kV/cm showed limited in microbial reduction. Also, total phenolic contents and antioxidant activity such as DPPH and FRAP, significantly decreased depending on treatment numbers of PEF (p<0.05).

Finite element analysis using Tower of the beam element. Investigate the mechanisms leg buckling of tower parts. Characterization of the role and behavior of aids and aids to optimize the use of the present one square Envoy maximize workability and economy. The proposed square Envoy existing triangle to reveal that more than reasonable and the absence of nodal wind load compared to the size of history.

Blast furnace slag is recycled as high value-added material, while steel slag is difficult to recycle or is recycled as low value-added one relatively due to its expansion collapsability. It's property is caused by the high content of Free-CaO and unstable steel oxides. Currently, a technique to subdivide the process refining is introduced, can be divided into the electric furnace steel slag and reducing steel slag. In this study, Free-CaO in the electric arc furnace slag by the ethylene glycol method for the quantitative evaluation for the expansion to proceed with construction materials, electric arc furnace slag oxidation is to use.

The possibility to determine the setting time of cement paste using the electrical impedance response of early-age hydrating cement paste is investigated. Electrical impedance responses of cement paste are continuously measured immediately after mixing and during hydration process. Measured responses are then analyzed and compared with temperature responses of hydrating cement paste.

일반적으로 송전철탑 부재들의 보강은 적절한 그라우팅재를 활용한 인젝션과 구조 보강재 부착을 이용한 단면 확장에 따른 강성보강 방식을 주로 사용한다. 이와 같은 그라우팅 인젝션 및 단면보완은 주로 축력능력을 확장시키는 데에 의미를 갖는다. 그렇지만 보다 안정적 상태를 유지케 할 수 있는 보강방안이 적극 요구되는데 그 방법은 좌굴에 의해 손상을 받은 부재를 원상태의 길이로 환원시키고, 또한 내부적 보강효과를 동시에 갖는 새로운 부재로 교체하는 것이다. 본 연구에서는 기초침하로 구조적 손상을 받은 송전철탑의 손상회복을 위한 실증적 과정으로 우선 현장에서의 손상도 확인점검과 손상상태 및 회복상태에 대한 수치 해석적 결과를 도출하였고, 새롭게 고안한 잭킹시스템을 이용하여 보강된 부재를 교체하는 과업을 수행하였다. 이 결과는 송전철탑 유지관리의 차원상승 효과를 갖게 한다.

The effects of pretreatment by pulsed electric fields (PEFs) on the juice expression characteristics of the Malus pumila fruit were investigated. Fresh fruits were divided into quarters, were produced on a laboratory scale (100 g apples per lot) by pretreatment with electric fields at two different field intensities (1, 2 kV/cm; n=50, 100, 200, and 400 pulses), and were then pressed at room temperature. Relative to the control samples, the juice yield increased with increasing field intensities. The total phenolics and antioxidant activity were higher in the juice from the PEF-treated fruit than in the juice from the untreated fruit. There was no significant difference in soluble-solid and reducing sugar contents between the PEF-treated and untreated fruits. These results suggest that PEF pretreatment may be useful for increasing the juice yield, total phenolics, and antioxidant activity of the Malus pumila fruit.

Replacement aggregate source like as electric arc furnace slag will be important more and more in the domestic construction field. Recently KS F 4715 was revised in order to utilize electric arc furnace slag as concrete aggregate. However, stability for an actual structure has not been confirmed sufficiently. Therefore, more careful attention should be paid on the quality management of slag aggregate. To evaluate the volume stability of electric arc furnace slag, a method of immersion expansion for evaluating road aggregate has been used. These conventional method needs long time, so there are many demands from industry for fast testing method. This paper is intended to evaluate whether the acceleration test method in the hydro thermal condition is proper or not, and find the correlations between the volume expansion and oxide compounds of slag aggregate. The test results indicates that the acceleration test method has sufficient possibility as a way of evaluating the safety of electric arc furnace slag, and that there is no correlations between the volume expansion of mortar bar with slag aggregate and the oxide compositions of slag aggregate, but the main cause of the pop-out phenomenon is the MgO content of slag aggregate.

For utilization of Electric Arc Furnace Slag’s high added value, KS F 4571 was revised, so the institutional environment to use concrete aggregate was prepared. But, it has hardly been reported how much the slag occurring in actual steel-making plants meets KS requirements. Therefore, this study was intended to analyze various engineering features of electric arc furnace slag, which occur in diverse kinds of electric arc furnace process to manufacture reinforcing rebar, hot roll, and shape steel, in accordance with KS and relevant standards. The test results from this study showed that electric arc furnace slag occurring in Korea didn’t meet the standards relating to many physical properties, such as water absorption, grading, unit volume weight, and material passing standard sieve 0.08 mm which are required for concrete aggregate and are prescribed in KS F 4571, and therefore that something is needed to be improved. Regarding chemical properties, heavy metal solubility based on official wastes test method, CaO and FeO were met, but content of MgO related to expansion and basicity exceeded or came close to standards. Therefore, it was found that some measures should be taken to address the issue.

이 연구에서는 철강 공정에서 발생되는 전기로 산화슬래그 골재를 사용한 철근콘크리트 보의 전단 성능을 평가하였다. 이를 위하여 총 6개의 단순지지형 실험체를 제작하여 전단실험을 수행하였다. 주요 실험변수는 골재의 종류와 전단철근의 유무로 하였다. 실험체는 전단경간비가 2.5, 폭 200mm, 유효깊이가 300mm인 직사각형 단면으로 4점가력을 받도록 계획하였다. 기존 강도식을 사용하여 실험체의 전단강도를 예측하였으며, 전단해석모델을 사용한 유한요소해석을 수행하여 전기로 산화슬래그 골재를 사용한 실험체의 전단거동을 예측하였다. 실험결과로부터, 전기로 산화슬래그 골재를 사용한 실험체의 전단 성능은 천연골재를 사용한 실험체와 서로 유사한 것을 확인할 수 있었다.