• Title/Summary/Keyword: Mechanical Loss

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Analysis of Mechanical Properties of Solidified soil using Pig Iron Slag (용선슬래그를 활용한 고화토의 역학적 특성 분석)

  • Yang, Chul-Jin;Bae, Jun-Seok;Byun, Ho-Seok;Lee, Kang-Hwi;Lee, Jong-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.1-10
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    • 2018
  • We conducted research to develop a solidification agent for the ground surface reinforcement method in which activator is fused by recycling pig iron slag, which is a byproduct generated in the steel making process. The purpose of this research is to solve the problems of surface soil by improving the strength and durability of foundation soil such as soil loss, settlement, sinkhole, etc. by recycling pig iron slag from disused or landfilled steelworks. For this purpose, the possibility of using pig iron slag as a solidification soil was evaluated by the compressive strength, elution test of harmful materials, permeability coefficient test. As a result of the compressive strength test, the values of the strength of the curing 28 days of the solidified soil having the solidification agent mixing ratio of 12% were found to be 0.93, 0.96 and 1.3 MPa, respectively, satisfying the required strength value of 1 MPa, In the case of permeability coefficients, the minimum values were $4.1{\times}10^{-8}$, $7.0{\times}10^{-7}$, and $1.7{\times}10^{-7}cm/sec$, respectively, at the solidification agent mixing rate of 12%. In addition, as a result of the elution test of harmful materials, a small amount was detected in the item of hexavalent chromium but satisfied the inclusion criteria, and in the remaining items, heavy metals were not eluted.

RESTORATION OF MAXILLARY PRIMARY INCISORS USING POLYETHYLENE FIBER-REINFORCED POST (폴리에틸렌 섬유 강화형 포스트를 이용한 상악 유전치의 수복)

  • Yun, Hyo-Jin;Park, Ho-Won;Lee, Ju-Hyun;Seo, Hyun-Woo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.37 no.4
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    • pp.526-531
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    • 2010
  • Early childhood caries which mainly affect maxillary anterior area, defined as 'the presence of 1 or more decayed, missing, or filled tooth surfaces in any primary tooth in a child 71 months of age or younger'. Extraction of teeth when early childhood caries affected in maxillary primary incisors often develops progressively, result in severe destruction of crowns, acute or chronic pulpitis, and periapical abscess formation. Maxillary primary incisors are need to preserve as possible, because the early loss of maxillary primary incisors may lead to various functional, esthetical, and psychological problems. It is necessary to the availability of an easy to perform technique capable of providing efficient, durable, functional, and esthetic restorative methods. Polyethylene fiber-reinforced post can be used in strengthen of composite resins that is esthetic and good physical and mechanical properties. $Ribbond^{(R)}$ is made from an polyethylene fiber, has numerous usages, its surface is treated to enhance adhesion to resins, ease of manipulation, relatively cost effective. We report this case, had restored of maxillary primary incisors with severe coronal destruction due to affecting severe early childhood caries, using polyethylene fiber-reinforced posts, composite resin cores, and celluloid crowns. We could obtain good result of treatment.

Quality Characteristics of Pound Cakes Prepared with Flowering Cherry (Prunus serrulata L. var. spontanea Max. wils.) Fruit Powder during Storage (버찌(Fruit of Prunus serrulata L. var. spontanea Max. wils.) 분말을 첨가한 파운드케이크의 저장 중 품질 특성)

  • Kim, Kyoung-Hee;Hwang, Hye-Rim;Yun, Mi-Hyang;Jo, Ji-Eun;Kim, Mi-Seon;Yook, Hong-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.7
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    • pp.926-934
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    • 2009
  • The study investigated the quality of pound cake prepared with various concentrations of cherry powder (obtained from ground fruit of Prunus serrulata L. var. spontanea Max. wils.). Pound cake was evaluated for their sensory property and physical quality stored for 10 days at $25^{\circ}C$. The pH of the batter decreased with rising cherry powder concentration. The specific loaf volume and height decreased (from 2.95 to $2.60\;cm^3/g$) with increasing in cherry powder. The baking loss rate of the pound cake tended to increased by $11.47{\sim}12.67%$, but with no significant differences. The lightness, redness, and yellowness values were significantly decreased with increases in cherry powder except for redness of pound cake crumb. As the concentration of cherry powder increased, the mechanical characteristics of the pound cake did not differ significantly. The hardness tended to increase, while adhesiveness and springiness decreased with increases in powder. The retrogradation degree of pound cake prepared with cherry powder was higher than the control but there were no significant differences. For the antioxidative activity measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, pound cake prepared with 10% and 15% added cherry powder showed high antioxidant activities. The pound cakes containing 10 and 15% cherry powder had acceptable sensory properties, such as flavor, taste, softness, moisture, and overall acceptability. The results exhibited that adding the cherry powder into the pound cake increased antioxidant activity with the highest quality improvement obtained by incorporating 10% (w/w) of cherry powder into the pound cake formula.

Development of a Moving Body Type Wave Power Generator using Wave Horizontal Motions and Hydraulic Experiment for Electric Power Production (파의 수평운동을 이용한 가동물체형 파력발전장치의 개발과 전력생산에 관한 수리실험)

  • Hwang, Seong Su;Lee, Dong Soo;Yang, Kyong Uk;Byun, Jung Hwan;Park, Il Heum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.2
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    • pp.73-80
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    • 2016
  • To reduce the mechanical energy loss and to get the high energy efficiency, an apparatus of wave power generation inducing a consistent one way rotating motion from the wave reciprocation motions was developed and the hydraulic experiments for the real electric power production were conducted and the results were discussed. In the experiments for the shape of the buoyant tank, the efficiency of the fixed 9 cm diameter type enduring the wave plate weight was 14.6% and this was the best result for all shapes. But although the free sliding type was expected to represent a high efficiency, the experiments did not show a good result as 8.5% efficiency. Therefore, the shape of buoyant tank was decided as the fixed 9 cm diameter type in the next all tests. In the experiments for the various incident waves, when the water depth was 90 cm, the average efficiencies were measured as 3.9% in the 2nd gear, 4.9% in the 3rd gear, 4.9% in the 4th gear, 12.0% in the 5th gear, 10.0% in the 6th gear, 3.1% in the 7th gear, and 3.0% in the 8th gear. Also, when the water depth was 80 cm, the average efficiency was shown as 15.0% with 5th gear condition. Therefore the high average efficiency as 13.5% was given with 80~90 cm water depth and the 5th gear in the model.

Parametric Study for the Optimal Integration Design between the Gas Turbine Compressor and the Air Separation Unit of IGCC Power Plant (석탄가스화 복합발전플랜트 가스터빈 압축기와 공기분리장치 간의 최적 연계설계를 위한 매개변수연구)

  • Lee, Chan;Kim, Hyung-Taek
    • Journal of Energy Engineering
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    • v.5 no.2
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    • pp.160-169
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    • 1996
  • Parametric studies are conducted for optimizing the integration design between gas turbine compressor and air separation unit (ASU) of integrated gasification combined cycle power plant. The present study adopts the ASU of double-distillation column process, from which integration conditions with compressor such as the heat exchanger condition between air and nitrogen, the amount and the pressure of extracted air are defined and mathematically formulated. The performance variations of the compressor integrated with ASU are analyzed by combining streamline curvature method and pressure loss models, and the predicted results are compared with the performance test results of actual compressors to verify the prediction accuracy. Using the present performance prediction method, the effects of pinch-point temperature difference (PTD) in the heat exchanger, the amount and the pressure of extracted air on compressor performances are quantitatively examined. As the extraction air amount or the PTD is increased, the pressure ratio and the power consumption of compressor are increased. The compressor efficiency deteriorates as the increase of the flow rate of air extracted at higher pressure level while improving at lower pressure air extraction. Furthermore, through the characteristic curve between generalized inlet condition and efficiency of compressor, optimal integration condition is presented to maximize the compressor efficiency.

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Defect Depth Measurement of Straight Pipe Specimen Using Shearography (전단간섭계를 이용한 직관시험편의 결함 깊이 측정)

  • Chang, Ho-Seob;Kim, Kyung-Suk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.2
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    • pp.170-176
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    • 2012
  • In the nuclear industry, wall thinning defect of straight pipe occur the enormous loss in life evaluation and safety evaluation. To use non-destructive technique, we measure deformation, vibration, defect evaluation. But, this techniques are a weak that is the measurement of the wide area is difficult and the time is caught long. In the secondary side of nuclear power plants mostly used steel pipe, artificiality wall thinning defect make in the side and different thickness make to the each other, wall thinning defect part of deformation measure by using shearography. In addition, optical measurement through deformation, vibration, defect evaluation evaluate pipe and thickness defects of pressure vessel is to evaluate quantitatively. By shearography interferometry to measure the pipe's internal wall thinning defect and the variation of pressure use the proposed technique, the quantitative defect is to evaluate the thickness of the surplus. The amount of deformation use thickness of surplus prediction of the actual thickness defect and approximately 7 percent error by ensure reliability. According to pressure the amount of deformation and the thickness of the surplus through DB construction, nuclear power plant pipe use wall thinning part soundness evaluation. In this study, pressure vessel of thickness defect measure proposed nuclear pipe of wall thinning defect prediction and integrity assessment technology development. As a basic research defected theory and experiment, pressure vessel of advanced stability and soundness and maintainability is expected to contribute foundation establishment.

A Comparison of Fattening Performance, Physico-Chemical Properties of Breast Meat, Vaccine Titers in Cross Bred Meat Type Hybrid Chicks Fed Sulfur (유황을 급여한 육용 교잡계의 성장능력과 계육의 물리.화학적인 성상의 비교)

  • 박재홍;류명선;이영은;송근섭;류경선
    • Korean Journal of Poultry Science
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    • v.30 no.3
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    • pp.211-217
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    • 2003
  • A study was conducted to investigate the fattening performance, physico-chemical properties of breast meat, vaccine titers in cross bred meat type hybrid chicks fed organic sulfur. Total three hundred and sixty chicks of eight weeks old were replaced in individual cage from 8 to 10 weeks old. Four levels of organic sulfur (0, 1.0, 2.0, 4.0%) containing 45% sulfur were added into basal diet containing CP 19% and ME 2,950 kcal/kg. Weight gain, feed intake, fred conversion were weekly measured. The proximate composition, physico-chemical properties of breast meat, vaccine titer and sensory characteristics were examined at the end of experiment. Weight gain, feed intake and feed conversion of birds fed organic sulfur were not statistically different with control. There were no significant difference in feed intake and feed conversion. However, abdominal fat(%) of birds fed organic sulfur tended to increase compared with control. Crude fat of breast meat decreased significantly in organic sulfur treatments(P<0.05). The red color of breast meat seemed to increase but was not statistically different among the treatments. Cooking loss showed decrements significantly in organic sulfur treatments(P<0.05). Mechanical Hardness, cohesiveness and springiness were prone to be high and gumminess greatly high in breast meat of birds fed organic sulfur addition compared with control. Juiciness tended to increase and greasiness decreased(P<0.05) in organic sulfur treatments by the sensory evaluation. The overall acceptability of the breast meat was the highest at 2.0% organic sulfur added chicks(P<0.01). There were no different blood cholesterol, AST, ALT and BUN.

Effect of Corrosion Environment on the Fretting Wear Corrosion of a Hinge Material( I ) (힌지재료의 찰과마멸부식에 미치는 부식환경의 영향( I ))

  • Kwak Nam-In;Lim Uh-Joh;Lee Jong-Rark
    • Journal of the Korean Institute of Gas
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    • v.4 no.1 s.9
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    • pp.26-32
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    • 2000
  • The fretting wear corrosion characteristics between the SM20C and the SM20C, the YBsC3 and the STC4H was experimented by using radical type friction experimental device under the corrosion environment of atmosphere, neutral solution, acid solution and chemical factors of the sea water. The affection of underground water that affect fretting wear corrosion of the SM20C which is moving specimen was more sensitive at the STC4H and more insensible at the YBsC3. The affection of underground water that affect fretting wear corrosion of the STC4H was less, but in the $0.5\%\;H_2SO_4$ and $0.5\%\;HNO_3$ solutions the fretting wear corrosion of the STC4H was more large. The fretting wear corrosion of the SM20C which is moving specimen in the underground water was less than in the $3.5\%\;NaCl$, $0.5\%\;H_2SO_4$ and $0.5\%\;HNO_3$ solutions. As time passed, the fretting wear corrosion is increased in the $HNO_3$ solution and dull in the $0.5\%\;H_2SO_4$ solution.

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Effects of Yuklinzu on the ovariectomized rat model of postmenopausal osteoporosis (육린주가 난소적출 백서의 골다공병에 미치는 영향)

  • Choi Sang Soon;Uem Ju O;Kim Song Baek;Yoo Sim Keun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.4
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    • pp.788-800
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    • 2002
  • Aging is characterized by an age-dependent reduction in bone density. Pronounced bone loss by postmenopausal estrogen deficiency induces a bad effect on dynamic balance of bone metabolism. When the bone density is reduced to the level below the fracture threshold, the risk for fracture is greatly increased. The purpose of this study is to examine what are the effects of the Yuklinzu(YLZ: 毓麟珠) on the ovariectomized rat model of postmenopausal osteoporosis. The results of the experiment are as follows: Body weight in control group showed significant increase in comparison with sham, but that in YLZ-treated showed no change in comparison with control. The level of serum albumin in control group showed significant decrease in comparison with sham. That in YLZ-treated was slightly decreased in comparison with control. The level of serum ALP activity in control group showed significant increase in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. The level of serum phosphorous in control group showed significant increase in comparison with sham, but that in YLZ-treated showed no change in comparison with control. The level of serum calcium in control group showed no change in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. The level of serum GOT in control group showed no change in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. The level of serum GPT did not significant change among the three groups. The level of serum estrogen in control group showed slightly increased in comparison with sham, but that in YLZ-treated showed no change in comparison with control. The level of serum T3 in control group showed no change in comparison with sham, and that in YLZ-treated showed no change in comparison with control. The level of serum T4 in control group showed significant increase in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. Mechanical strength of the femur neck in control group showed significant decrease in comparison with sham. That in YLZ-treated showed slightly increased in comparison with control. Trabecular bone area as well as trabecular thickness in control group showed significant decrease in comparison with sham. Those in YLZ-treated showed significant increase in comparison with control. Trabecular number and did not significant change among the three groups. Trabecular separation only in YLZ-treated showed significant decrease in comparison with control. Osteoclast number and oseoblast surface in control group showed significant increase in comparison with sham. Those in YLZ-treated showed slightly decreased in comparison with control. According to the above these results, YLZ has shown to be capable of preventing and curing osteoporosis caused by old-aged and postmenopause.

Assessment of a Pre-conceptual Design of a Spent PWR Fuel Disposal Container (가압경수로형 사용후핵연료 처분용기의 예비 개념설계 평가)

  • Choi, Jong-Won;Cho, Dong-Keun;Lee, Yang;Choi, Heui-Joo;Lee, Jong-Youl
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.1
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    • pp.41-50
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    • 2006
  • In this paper, sets of engineering analyses were conducted to renew the overall dimensions and configurations of a disposal container proposed as a prototype in the previous study. Such efforts and calculation results can provide new design variables such as the inner basket array type and thickness of the outer shell and the lid & bottom of a spent nuclear fuel disposal container. These efforts include radiation shielding and nuclear criticality analyses to check to see whether the dimensions of the container proposed from the mechanical structural analyses can provide a nuclear safety or not. According to the results of the structural analysis of a PWR disposal container by varying the diameter of the container insert, the Maximum Von Mises stress from the 102 cm-container meets the safety factor of 2.0 for both extreme and normal load conditions. This container also satisfies the nuclear criticality and radiation safety limits. This decrease in the diameter results in a weight loss of a container by $\sim20$ tons.

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