• 제목/요약/키워드: surface changes

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반응표면분석에 의한 Maillard 반응기질의 동적변화 모니터링 (Monitoring of Dynamic Changes in Maillard Reaction Substrates by Response Surface Methodology)

  • 이기동;김정숙;권중호
    • 한국식품과학회지
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    • 제28권2호
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    • pp.212-219
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    • 1996
  • Maillard 반응중 피질의 변화를 4차원 반응표면으로 나타내어 기질의 동적변화를 모니터링하고자 하였다. Total amino acids의 함량변화에 대한 회귀분석 결과 높은 $R^2$ (0.9470)를 나타내었으며, 각각의 amino acid또한 높은 R'를 나타내어 대부분 유의성이 인정되었다. 유리당의 함량에 대한 회귀분석에서 glucose의 함량에 대한 R'는 0.9250이었으나 fructose에 대한 $R^2$는 0.6490으로 낮은 값을 보였다. Maillard반응중 total amino acids의 함량은 반응온도가 높고 용매의 pH값 이 증가할수록 크게 감소되었다. 반응생성물의 갈색도는 반응온도가 증가할수록 증가하나 145‘C 내외에서 최대값을 나타내었다. 각각의 amino acid함량변화는 total amino acids 함량인화와 유사한 경향이었으며, 4차원 반응표면분석 결과 aspartic acid, threonine, glucose등의 기질들은 복합기질계 Maillard반응에 있어서 특이하게 반응온도가 증가할수록 크게 감소한 반면, 용매의 pH와 반응시간의 영향은 거의 받지 않는 것으로 나타났다.

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슬랙스의 동적 적합성 향상을 위한 설계 요인 연구 (A Study on the Design Factor for Increasing the Dynamic Fit of Slacks)

  • 조성희
    • 복식
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    • 제58권2호
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    • pp.162-180
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    • 2008
  • The purpose of this study is to find the basic design factors that affect the changes in body surface lines caused by lower limb movements, thereby resulting in slacks that fit well regardless of whether the human form is static or in motion. Using unmarried female university students aged 18-24 as subjects, a total of 32 body surface lines (15 body surface total lines and 17 body surface segment lines) were measured in one static and 9 movement poses, The analysis first involved the calculation of the expansion and contraction rates per body part in body surface line in 9 lower limb movements, Second, a factor analysis was conducted using the expansion and contraction rates of these changes in body surface line. The results of this study are as follows, According to the factor analysis, basic design factors that affect changes in body surface lines comprised 8 types of factors as illustrated in fig, 2-fig, 9, which explained 79.2% of total variate for the variables studied, Factor 1, comprising the lower segment of center back leg line, center front leg line and inner leg line, and lower limb girth except midway thigh girth and ankle girth below hip girth, accounted for 30.3% of total variance, Factor 2, comprising waist girth, the total and upper segment of center back leg line and center tront leg line, and front and back segment of crotch length, explained 17.4% of total variance, Factor 3, the total and upper segment of lateral leg line at the center, accounted for 56.5% of total variance in accordance with Factors 1, 2, and 3, Factor 4 was the contracting upper part of lower leg between legscye girth and midway thigh girth, Factor 5 comprised the total and upper segment of inner leg line and posterior knee girth, Factor 6 was the total crotch length, Factor 7 was the ankle girth, Factor 8 was the abdomen girth.

실험적 외상성교합이 치주조직의 혈관에 미치는 영향에 관한 연구 (Vascular Changes of the Periodontium in Experimental Trauma from Occlusion)

  • 김기효
    • 대한치과보철학회지
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    • 제9권1호
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    • pp.53-57
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    • 1969
  • Trauma from occlusion causes apparent changes in the blood vessels of the periodontal ligament. The initial response is primarily mechanical, due to compression, and secondarily characterized by necrotic changes. Recently, many investigators are concerned with vascular changes in relation to the loss of the alveolar bone. Author observed vascular changes of the periodontium in the experimental trauma from occlusion on rats. The results were observed as follows.: 1) There were no remarkable changes in the gingiva. 2) The blood vessels that normally occupied a position closer to the bone surface showed a displace-ment toward the cemental surface due to trauma from occlusion. 3) There were no appreciable changes of the alveolar bone in the initial period of trauma from occlusion, whereas there was excessive resorption of the alveolar bone in the long range.

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도시 확장에 따른 온열환경의 변화 (Change of Thermal Environment with Urban Expansion)

  • 김상진
    • 한국태양에너지학회 논문집
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    • 제27권2호
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    • pp.95-101
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    • 2007
  • The surface changes due to urban expansion and the increase of artificial heat releases have brought significant climate changes such as heat island phenomenon in urban area. Furthermore, these changes also have brought serious problems such as air temperature increase, wind changes, and air pollution in urban area. Comprehensive analytical technologies considering various effects are required to analyse complicated mechanism of climate changes, and review the efficient measures. In this research, the effect of the urban expansion in Tokyo and Bangkok area on urban environment will be discussed. By using CFD, urban development and the mechanism of global warming and wind change are studied in those two cities. As a result of numerical research, the surface changes of city could bring the environmental changes in urban area.

기후변화에 따른 한국 연근해 어업생산량 변화 분석 (An Analysis of Changes in Catch Amount of Offshore and Coastal Fisheries by Climate Change in Korea)

  • 엄기혁;김홍식;한인성;김도훈
    • 수산경영론집
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    • 제46권2호
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    • pp.31-41
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    • 2015
  • This study aimed to analyze the relationship between sea surface temperature as a climatic element and catch amount of offshore and coastal fisheries in Korea using annual time series data from 1970 to 2013. It also tried to predict the future changes in catch amount of fisheries by climate change. Time series data on variables were estimated to be non-stationary from unit root tests, but one long-term equilibrium relation between variables was found from a cointegration test. The result of Granger causality test indicated that the sea surface temperature would cause directly changes in catch amount of offshore and coastal fisheries. The result of regression analysis on sea surface temperature and catch amount showed that the sea surface temperature would have negative impacts on the catch amount of offshore and coastal fisheries. Therefore, if the sea surface temperature would increase, all other things including the current level of fishing effort being equal, the catch amount of offshore and coastal fisheries was predicted to decrease.

습식 식각에 의한 실리콘 웨이퍼의 표면 및 전기적 특성변화(1) - 불산 농도에 따른 표면형상 변화 - (Change of Surface and Electrical Characteristics of Silicon Wafer by Wet Etching(1) - Surface Morphology Changes as a Function of HF Concentration -)

  • 김준우;강동수;이현용;이상현;고성우;노재승
    • 한국재료학회지
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    • 제23권6호
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    • pp.316-321
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    • 2013
  • The electrical properties and surface morphology changes of a silicon wafer as a function of the HF concentration as the wafer is etched were studied. The HF concentrations were 28, 30, 32, 34, and 36 wt%. The surface morphology changes of the silicon wafer were measured by an SEM ($80^{\circ}$ tilted at ${\times}200$) and the resistivity was measured by assessing the surface resistance using a four-point probe method. The etching rate increased as the HF concentration increased. The maximum etching rate 27.31 ${\mu}m/min$ was achieved at an HF concentration of 36 wt%. A concave wave formed on the wafer after the wet etching process. The size of the wave was largest and the resistivity reached 7.54 $ohm{\cdot}cm$ at an 30 wt% of HF concentration. At an HF concentration of 30 wt%, therefore, a silicon wafer should have good joining strength with a metal backing as well as good electrical properties.

허스롤 목 부위 형상 변화에 따른 열응력 분포 변화 유한요소해석 (Finite Element Analysis of Thermal Stresses on a Hearth Roll Surface Depending on Changes in the Neck Shape)

  • 나두현;이영석
    • 소성∙가공
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    • 제25권3호
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    • pp.169-175
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    • 2016
  • The hearth roll, which transfers the cold-rolled strip sheet in a Continuous Annealing Line (CAL), is always subjected to changes in the surface temperature and subsequently experiences thermal stress in service. These variations lead to the generation of thermal cracks on the hearth roll surface as well local plastic deformation. We performed finite element analysis to predict the thermal stress changes on the hearth roll surface and designed the collar shape of the hearth roll to minimize these thermal stresses. Results show that the hearth roll with a collar having an obtuse angle is much more effective than a hearth roll with collar having a right angle when the tangential stress, which is one of main causes leading to surface cracks, is compared for the various conditions. It was found that the tangential stress and the temperature on the surface of hearth roll can be reduced by 51.9% and 26℃ if the shape of roll on collar is re-designed.

Surface structure characteristics of dental implants and their potential changes following installation: a literature review

  • Pitchaya Aneksomboonpol;Basel Mahardawi;Pheeradej Na Nan;Palawat Laoharungpisit;Thongnard Kumchai;Natthamet Wongsirichat;Napapa Aimjirakul
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제49권3호
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    • pp.114-124
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    • 2023
  • Dental implants have been utilized for many years to treat individuals with missing teeth. To optimize the long-term success rate of such implants, new designs, surfaces, and materials have been analyzed. It is important for the clinician to have a background in the field of implant surface design, to be familiar with the strengths and limitations of the available options, and to be aware of the alterations in surface structure that may occur following installation. This article provides a detailed review of the structure and the surface characteristics of dental implants, the modifications of implant surface, as well as the methods of evaluating implant surface structure. Moreover, it provides information concerning the structural changes that may take place at the time of dental implant placement. It is important for clinicians to be aware of such changes to plan and execute implant procedures with the highest possible success and implant survival rates.

금속의 Surface Integrity에 미치는 소성스트레인의 영향 (Effect of Plastic Strain on the Surface Integrity of Steel)

  • 김태영
    • 한국정밀공학회지
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    • 제6권4호
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    • pp.94-102
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    • 1989
  • The effect of plastic strain on the surface integrity of mild steel (SS 41) was studied. This paper shows that the recrystallization technique is adequate to evaluate the plastic strain in a machined surface experimentally. The relations between the plastic strain and the machining conditions are quantitatively evaluated by using the recrystallization technique. The obtained results are summarized as follows. 1. The surface integrity of steel is considerably influenced by the amount of surface region deformation produced by changes in cutting conditions. 2. The plastic strain in machined surface produced by changes of the cutting conditions is evaluated by the recyrstallization technique. 3. The plastic strain increases with the increase of depth of cut and the decrease of rake angle. 4. When the cutting force is high and the rake angle is small, the value of maximum true strain reaches to high. 5. The maximum true strain is related to the cutting energy, and the values increase with the increase of the unit shear and total engergy in constant depth with the increase of the energy values.

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