• 제목/요약/키워드: Brittleness

검색결과 703건 처리시간 0.026초

두유 첨가에 따른 도토리식빵의 색도 및 조직감 특성 변화 (Changes in Color and Textural Properties of Acorn Bread According to Added Amount of Soymilk)

  • 김정미;윤계순;주정임
    • 한국식생활문화학회지
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    • 제31권6호
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    • pp.605-615
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    • 2016
  • The objective of this study was to prepare acorn bread added with soymilk in order to improve its quality and develop the best possible recipe. The loaf volume, color, texture and sensory evaluation of acorn bread added with soymilk 10~40% were measured during the storage period. The L-value significantly decreased upon addition of 40% soymilk. A-value increased, but b-value decreased. During the storage period, the L- and a- values increased except 2 days at room temperature and 7 days in a freezer, whereas b-value decreased. For textural measurement, hardness, springiness, gumminess and brittleness increased significantly upon addition of soymilk. However cohesiveness decreased for 2 days of storage, whereas gumminess and brittleness for 1 day of storage at room temperature. Freezer storage for 1 day reduced cohesiveness, and gumminess for 4 and 7 days, respectively, and brittleness after all storage periods. The sensory evaluation showed that acorn bread added with soymilk 20% produced the best results in color and taste. The bitter aftertaste increased according to addition of soymilk with lower scores. Softness, chewiness and overall preference decreased significantly. Therefore, 10% soymilk addition got the best scores in aftertaste, softness, chewiness and overall acceptances.

Bonded-cluster simulation of tool-rock interaction using advanced discrete element method

  • Liu, Weiji;Zhu, Xiaohua;Zhou, Yunlai;Li, Tao;Zhang, Xiangning
    • Structural Engineering and Mechanics
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    • 제72권4호
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    • pp.469-477
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    • 2019
  • The understanding of tool-rock interaction mechanism is of high essence for improving the rock breaking efficiency and optimizing the drilling parameters in mechanical rock breaking. In this study, the tool-rock interaction models of indentation and cutting are carried out by employing the discrete element method (DEM) to examine the rock failure modes of various brittleness rocks and critical indentation and cutting depths of the ductile to brittle failure mode transition. The results show that the cluster size and inter-cluster to intra-cluster bond strength ratio are the key factors which influence the UCS magnitude and the UCS to BTS ratio. The UCS to BTS strength ratio can be increased to a more realistic value using clustered rock model so that the characteristics of real rocks can be better represented. The critical indentation and cutting depth decrease with the brittleness of rock increases and the decreasing rate reduces dramatically against the brittleness value. This effort may lead to a better understanding of rock breaking mechanisms in mechanical excavation, and may contribute to the improvement in the design of rock excavation machines and the related parameters determination.

Enhancing ductility in carbon fiber reinforced polymer concrete sections: A multi-scale investigation

  • Moab Maidi;Gili Lifshitz Sherzer;Erez Gal
    • Computers and Concrete
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    • 제33권4호
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    • pp.385-398
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    • 2024
  • As concrete dominates the construction industry, alternatives to traditionally used steel reinforcement are being sought. This study explored the suitability of carbon fiber-reinforced polymer (CFRP) as a substitute within rigid frames, focusing on its impact on section ductility and overall structural durability against seismic events. However, current design guidelines address quasi-static loads, leaving a gap for dynamic or extreme circumstances. Our approach included multiscale simulations, parametric study, and energy dissipation analyses, drawing upon a unique adaptation of modified compression field theory. In our efforts to optimize macro and microparameters to improve yield strength, manage brittleness, and govern failure modes, we also recognized the potential of CFRP's high corrosion resistance. This characteristic of CFRP could significantly reduce the frequency of required repairs, thereby contributing to enhanced durability of the structures. The research reveals that CFRP's durability and seismic resistance are attributed to plastic joints within compressed fibers. Notably, CFRP can impart ductility to structural designs, effectively balancing its inherent brittleness, particularly when integrated with quasi-brittle materials. This research challenges the notion that designing bendable components with carbon fiber reinforcement is impractical. It shows that creating ductile bending components with CFRP in concrete is feasible despite the material's brittleness. This funding overturns conventional assumptions and opens new avenues for using CFRP in structural applications where ductility and resilience are crucial.

Fabrication of transparent conductive thin films with Ag mesh shape using the polystyrene beads monolayer

  • Jung, Taeyoung;Choi, Eun Chang;Hong, Byungyou
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.313-313
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    • 2016
  • Transparent conductive oxide (TCO) films have many disadvantages, such as rarity, possible exhaustion, process temperature limitations, and brittleness on a flexible substrate. In particular, as display technology moves toward flexible displays, TCO will become completely unsuitable due to its brittleness. To address theses issue, many researchers have been studying TCO substitutes. In recent efforts, metal nanowires, conducting polymers, carbon nanotube networks, graphene films, hybrid thin films, and metal meshes/grids have been evaluated as candidates to replace TCO electrodes. In this study, we fabricated the TCO film with Ag meshes shape using polystyrene (PS) beads monolayer on the substrate. The PS beads were used as a template to create the mesh pattern. We fabricated the monolayer on the flexible substrate (PES) with the well-aligned PS beads. Electrodes with Ag mesh shape were formed using this patterned monolayer. We could fabricated the Ag mesh electrode with the sheet resistance with $8ohm{\Omega}/{\Box}$.

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경취성 난연삭 재료의 연삭특성 평가 (Evaluation of Grinding Characteristics on the Hardened-Brittle and Difficult-to-Grind Materials)

  • 곽태경;곽재섭;하만경;구양;류인일
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.1101-1104
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    • 2001
  • The special purposed materials, such as ceramics and stainless steel, are widely used in the various industrial area. They have properties of the higher strength of material, the wear-resistance, and the corrosion proof. But ceramics is a difficult-to-grind material which possesses the higher level of a strength and a brittleness. In this study, the theoretical investigation of a grinding force and of a surface roughness was conducted. The evaluations of grinding characteristics on the hardened-brittle and difficult-to-grind materials were experimentally carried out.

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세라믹스의 제거가공 기술 동향 (Review of Technology Trends for Ceramics Removal-Machining)

  • 곽재섭;곽태수
    • 한국정밀공학회지
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    • 제30권12호
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    • pp.1227-1235
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    • 2013
  • Ceramic materials are classified by oxide, nitride and carbide material and have high brittleness, strength and hardness. Ceramic materials are strong in compression but weak in shearing and tension. This review paper has focused on technology trends and mechanism analysis of ceramics removal machining. The ceramic materials have superior mechanical, physical and chemical properties, but it is very hard to machining and the use of ceramics has been limited because of high strength and brittleness. In this paper, technology trends of ceramic removal-machining was introduced for types of machining technology, abrasive machining, cutting process, laser machining and so on.

알루미나 연삭표면 특성에 관한 연구 (A Study on the Surface Characteristics n the Alumina Grinding)

  • 하상백
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.519-524
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    • 1999
  • To manufacture alumina products, sintering and grinding process are needed. In Al2O3 grinding, macro/micro surface fracture and cracks are easily occurred on the ground surface because of its high brittleness. In view point of fatigue fracture, surface profile produced by grinding is considered as notches. Therefore, it was reasonable that magnitudes and shapes of surface profiles effects on fatigue strength and life. Particularly, surface finish of Al2O3 which have high hardness and brittleness have an effect on fatigue strength. In this paper, some experiments are carried out to examine influence of grinding conditions to magnitude and shape of surface profile as well as the relationships of Ra, Rmax, Rmax/Ra, and Ku. Through the experimental results, It is found that Ra and Rmax was affected by grinding conditions, but Rmax/Ra and Ku was not. There are linear relations between Ra and Rmax, and between Rmax/Ra and Ku.

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돈육의 사후 처리시간이 유화형 소시지의 품질에 미치는 영향

  • 양한술;정진연;사우컷알리;주선태;박구부
    • 한국축산식품학회:학술대회논문집
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    • 한국축산식품학회 2005년도 제36차 추계 학술발표대회
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    • pp.157-160
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    • 2005
  • 사후처리시간에 따른 유화형소시지의 제조시 강직근의 낮은 pH는 제품의 유화안정성 및 가열감량을 높여 최종제품의 결착력 및 형태에 부정적인 영향을 미치는 것으로 사료되나, 이러한 낮은 수분보습력의 결과와는 달리 강직근 및 강직후근에 비해 낮은 명도 및 높은 적색도를 보여 온도체육의 가공 특성인 발색 향상과 일치하는 것으로 나타나 이에 대한 연구가 더 이루어져야할 것으로 판단된다. 또한 온도체육의 낮은 brittleness, hardness 및 gumminess은 제품의 결착력 감소에 따른 결과이며, 강직근의 높은 brittleness, hardness 및 gumminess은 사후강직을 통한 낮은 수분보습력에 기인한 것으로 사료된다.

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펙틴을 이용한 과즙젤리의 질감특성과 기호도 연구 (A Study of Textural Properties and Preferences of Fruit Pectin Jelly)

  • 최지영;송은승;정혜경
    • 한국식생활문화학회지
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    • 제9권3호
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    • pp.259-266
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    • 1994
  • This study was done to evaluate the effects of grape variety, pH and sugar contents on textural and sensory properties of grape pectin jelly. As a gelling agent, pectin 1% was selected due to highest sensory scores in preparatory experiments and also nutritional and economical reasons. To get the proximate composition of grape extract, moisture, pH, reducing sugar, and total titratable acidity was measured. Grape pectin jellies, made by 12 different recipies, were tested by sensory and instrumental evaluatoin. The results were as follows; 1) Hardness and chewiness were lowered in grape jelly which has lower pH and lower sugar contents. 2) People preferred grape jelly which has lower hardness, brittleness and sweetness, and higher sourness. 3) Comparing overall quality, Recipe C1 in Jelly 1 and recipe B1 in Jelly 2 were chosen as best. 4) Sensory hardness showed positive correlation with instrumental hardness, brittleness and chewiness.

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슬러리 충전 고성능 섬유 보강 시멘트 복합체의 역학적 성능 (Mechanical Performance of Slurry Infiltrated High Performance Fiber Reinforced Cementitious Composite)

  • 김현욱;이창준
    • 한국건축시공학회지
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    • 제17권2호
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    • pp.167-174
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    • 2017
  • 고비율의 고로슬래그를 사용한 슬러리 충전 고성능 섬유보강 시멘트 복합체(SI-HPFRCC)의 역학적 성능을 평가하였다. SI-HPFRCC 실험체 제작을 위해 hooked-end 형의 강섬유를 6.4% 사용하였다. 재령에 따른 압축강도 및 압축인성과 휨강도 및 휨인성 실험을 통해 SI-HPFRCC의 역학적 성능을 평가하였다. 또한 섬유보강 효과를 평가하기 위해 SI-HPFRCC 실험체 제작에 사용된 슬러리 매트릭스의 압축강도 및 휨강도를 측정하였다. 실험결과 SI-HPFRCC의 휨거동이 재령에 따라 취성이 증가함을 확인하였다. 압축거동의 경우에도 재령에 따른 취성 증가를 볼 수 있었으나 그 정도는 미미하였다. 강도측면에서 볼 때 SI-HPFRCC는 슬러리 매트릭스에 비해 약 140~190%의 압축강도 증가와 440~500%의 휨강도 증가를 보였다.