• 한국공작기계학회논문집
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• 제10권4호
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• pp.1-6
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• 2001

In the present industry, there are necessary to cut only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia), therefor it had been made the studies of non-ferrous metals by many scientists. we hope this kind of study will continue. The purpose of this study is to conduct the basic experiment about influencing of the feedrate adjustment and the change of the side rake angle at turning of non-feerous metals. As the results, the surface roughnesses were on the decrease with a side-rake angle and feedrate diminution in the case of the pastic, aluminum, and paulownia.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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• pp.88-89
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• 2011

The study on synthesis of carbon nanomaterials by H2 mixing in counterflow methane diffusion flames has been experimentally conducted. We have also investigated on effect of catalyst and temperature in flame. The counterflow flame was formed by many kind of gas (fuel side using $CH_4-H_2-N_2$ and oxidizer side $N_2-O_2$) and nitrogen shields discharge on each other side to cut off oxidizer of the atmosphere. Ferrocene was used as a metal catalyst for CNTs synthesis. substrate was used to deposit carbon nanomaterials and these were analyzed by FE-SEM. We could find that carbon nanotubes and many kind of carbon nano materials were formed in Cu wire substrate, through this experiment.

• 한국구조물진단유지관리공학회 논문집
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• 제6권2호
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• pp.175-182
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• 2002

The cement injection technology on the purpose of ground reinforcement and cut-off has been used in construction sites until now. However, recently it is applied to prevent leakage of underground structure. In this study, applicability of the back side waterproof grouting method was verified through performing field model tests and reviewing case histories. From the results of this study, injection shape of the back side waterproof grouting method was appeared to be root type, and waterproof effect by injection of cement grout material was excellent because grout material infiltrated into boundary between wall of structure and back side ground to be waterproof layer. Components influencing infiltration of injection material are type of soil and degree of compaction. For effective injection, injection pressure has to vary gradually from high pressure to low pessure and small quantity of injection material has to be injected for long times. Also, spacing of injection hole must be designed considering condition of back side ground, injection area, W/C ratio, the number of injection and injection pattern properly.

• 한국식품영양과학회지
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• 제36권5호
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• pp.622-628
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• 2007

Fresh-cut 채소 제품이 소비자에 의해 선택되어 소비되려면 이의 친환경적 원료생산과 가공, 포장, 서빙에 이르는 전 과정에서 체계적인 품질관리가 이루어져야 하며 갈변제어, 연화제어 및 미생물적 제어 등 관련 기술의 연구개발이 요구된다. 본 연구에서는 시중 유통 판매되고 있는 fresh-cut 채소제품의 품질을 비교평가하기 위해 현재 유통되고 있는 9개사 제품을 선정하였으며, 관능검사를 포함하여 vitamin C, 무기질, 중금속 함량, 잔류농약 및 미생물오염 정도를 조사하였다. 관능평가에서는 갈변 등 품질변화로 인해 전반적인 기호도가 그다지 높지 않았다. 채소류에서 중요 영양성분인 vitamin C 함량은 9개사 모든 제품의 주재료인 양상추에서 거의 검출되지 않았고 다른 채소류의 vitamin C 함량 역시 식품성분표보다 소량이었다. 무기질 함량 역시 극히 소량이었는데, 이는 박피, 절단 등의 최소 가공 공정을 거치면서 파괴되기 쉬운 vitamin C와 무기질이 대부분 손실되었기 때문으로 사료된다. 안전성측면에서 평가한 잔류 중금속 함량의 경우 몇 개의 제품에서 구리와 납이 소량 검출되었으며 잔류농약은 검출되지 않았다.

• 대한기계학회논문집A
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• 제41권5호
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• pp.391-399
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• 2017

절삭속도 및 이송속도가 평엔드밀로 하향절삭 가공된 측벽 형상에 미치는 영향을 실험을 통하여 알아보고자 한다. 실험은 절삭속도 및 공구 직경, 절삭날 당 이송거리를 변수로 하여 수행하며, 실험 결과로서 배분력과 축방향 형상을 측정한다. 연구 결과, 이송속도를 절삭속도로 나눈 값에 비례하는 날 당 이송거리가 작을수록 축방향 형상정밀도가 높아지는 것이 확인되었다. 아울러, 축방향 형상은 서로 다른 기울기를 갖는 두 직선이 특이점에서 만나는 형태로 단순화 할 수 있다. 그러므로 운전 중 작업자에 의한 형상정밀도의 추정 및 날 당 이송거리 조정에 의한 개선이 용이할 것으로 판단된다.

• 대한영양사협회학술지
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• 제26권2호
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• pp.116-125
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• 2020

The purpose of this study was to assess the sugars contents of home meal replacement (HMR) products currently sold in Korea. This study surveyed and examined the sugars contents in 835 popular HMRs (294 ready-to-eat foods; RTE, 499 ready-to-cook foods; RTC, 42 fresh-cut vegetables; FCV) through the nutrition labels. The average price, weight and energy content of 835 HMR products were 3,917.5 Korean won, 336.0 g, and 522.7 kcal, respectively. The sugars content per product was significantly higher in the RTCs (13.4 g) and RTEs (10.3 g) than that in the FCVs (4.2 g) (P<0.001), and the percentage of energy from sugars was 9.7% for the RTEs, 10.2% for the RTCs, and 8.7% for the FCVs without any significant difference. The sugars contents of 9 RTE types were in the order of side dishes (34.3 g), sunsik (22.5 g) and hamburgers (12.1 g) per package. The percentage of energy from sugars was highest in side dishes (28.1%), followed by kimchi (24.9%), sunsik (17.2%), and hamburgers (10.6%). Among 14 RTC types, the sugars contents were in the order of hot dogs (52.9 g), tteokbokki (30.4 g) and noodles (21.2 g) per package. The percentage of energy from sugars was the highest at 22.9% for sauces, followed by side dishes (17.3%), porridges (14.4%), instant stews (14.3%), and hot dogs (13.1%). Strategies and practices are needed to reduce the sugars contents of HMR producers and the sugars intakes of HMR consumers.

• 터널과지하공간
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• 제22권6호
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• pp.393-402
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• 2012

정상부가 개착된 암반사면에 지중경사계를 설치하여 개착사면의 내부 거동을 계측하였으며, 국지적으로 배후면 방향으로의 거동이 관찰되었다. 사면 거동, 특히 배후면 방향으로의 거동을 유발시키는 원인을 분석하기 위하여 시추작업을 수행하였다. 추출된 시추코어를 관찰하여 사면 암반의 암석학적 취약성을 조사하였으며, 공내 BIPS 영상을 취득하여 암반의 구조적 특성을 분석하였다. 코어 절리 시료를 이용하여 불연속면의 역학적 특성을 측정하였으며, 탄질물이 협재된 절리 시료에 대한 직접전단시험을 수행하여 전단강도를 측정하였다. 사면 거동에 대한 계측결과를 사면 암반과 탄질물이 협재된 절리들의 구조적 및 역학적 특성을 종합적으로 고려하여 해석하였으며, 절리에 협재된 탄질물 및 팽윤성 점토광물의 존재에 의해 국지적인 사면거동이 지배될 수 있는 잠재성을 확인하였다.

• Geomechanics and Engineering
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• 제32권1호
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• pp.111-123
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• 2023

The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m³ formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

• 한국안전학회지
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• 제30권1호
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• pp.47-51
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• 2015

In the study, a new non-open cut tunnel steel pipe method using slot hole has been developed. As is overcomes shortcomings of conventional methods, it is applied to the field. The main concept of the new method is the steel pipe pumping system with slot holes which, by means of formation slot holes between each steel pipe, applied to the magnitude of the relaxed earth pressure caused by excavation to the ground to prevent ground displacement. The stability of the support members and effect of displacement control of the new method were verified through several ways as numerical analysis and site test. The new method was applied to the construction of a 11.5m wide, 7.4m high and 50m long section that passes side subway and large buildings in inner city. By applying the new method, tunnel construction was successfully completed in 6 months. It decreases the construction period to 30% compared to that of conventional methods, and ground was almost negligible.

• 한국안전학회지
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• 제14권4호
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• pp.114-119
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• 1999

When NaOCl was generated and put into sea-water cooling machine in order to overcome the biological hindrances against sea-water cooling machine, it was converted into metallic ion, particularly Ca and Mg, as a hydrate in sea-water and is to stick to electrolyte as a side reaction. This phenomena make the distance between the electrolytes narrow to decrease the flow rate, which induces the local vortex flow which erodes the pole plate. Moreover, this increases the resistance of the electrolyte as well as voltage to decrease the electrolytic efficiency, which has curtailed a chlorine yield and caused a pole plate cut. We are able to overcome these problems by chemical cleaning and intend to extend the life-time of electrolyte and to increase output of the sea-water electrolysis facilities by studying optimal policy regarding chemical cleaning of electrolytic cell. Cleaning time of electrolytic facilities is determined when both increase in electrolytic efficiency and decrease in pole-plate voltage are 10%. At this time as operating current of electrolytic facilities is high, operating time is diminished. Whereas, parameter of end point determination according to cleaning is Mg ionic concentration in solution. When we use Cleaner as a 7wt% HCl, cleaning time is about 80min proper. We are able to maintain pole plate performance by protecting against pole plate cut by means of electrolytic by-product, improve operating rate of facilities, and cut down on maintenance expenditure after acidic cleaning.