• 제목/요약/키워드: Strength Index

검색결과 1,555건 처리시간 0.031초

전통한지의 종이 방향성 (Orientation properties of Korean traditional paper-Hanji)

  • 윤승락;나종범
    • 펄프종이기술
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    • 제45권3호
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    • pp.52-58
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    • 2013
  • To evaluate the anisotropic characteristics of Korean traditional paper-Hanji, the physical and mechanical characteristics of hand-made hanji, and machine-made hanji were investigated in this research. The densities of copying paper and newsprint paper appeared to be two times higher than the densities of hand-made hanji using Ssangbal sheet forming and hanji made of paper mulberry fiber. The breaking length, and tear index of both Hanji using Owangbal sheet forming, and hand-made Hanji using Ssangbal sheet forming appeared to be different according to the directions in paper. The breaking lengths of Hanji using Owangbal sheet forming showed little differences according to the directions. Breaking length of Hanji using Ssangbal sheet were slightly higher than those of Hanji using Owangbla sheet forming. The breaking lengths of machine-made hanji, copying paper, and newsprint paper were two to four times higher than those of hand-made Hanji. The breaking length showed higher differences according to the direction than the tear index. The tensile strength according to the directions in paper showed significant differences (${\alpha}$=0.05) in all papers used in this research.

3차원 보행분석을 통한 무릎 모음 모멘트와 고관절 내외회전의 임상적 특성 (Clinical Characteristics of Hip Joint Rotations and Knee Adduction Moment through 3D Gait Analysis)

  • 김용욱;강승묵
    • 대한통합의학회지
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    • 제5권4호
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    • pp.41-48
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    • 2017
  • Purpose : The purpose of this study was to verify the relationships among the knee adduction moment, hip rotation range, strength of hip rotators, and Foot Posture Index of healthy young adults. Method : Thirty-two healthy adults(24 male, 8 females) participated in this study. Subjects performed 5 walking trials to evaluate the knee adduction moments using a three-dimensional motion analysis system. Hip rotation ranges and hip rotator strengths were measured using a standard goniometer and a handheld dynamometer, respectively. The mean of three trials of clinical tests was used for data analysis. Results : The first peak knee adduction moment was significantly correlated with the hip rotation ranges and hip rotator strengths (P<.05). The second peak knee adduction moment was showed significant correlations with hip external rotation and rotation ratio. There were no correlations between Foot Posture Index and all knee adduction moments (P>.05). Conclusion : This study suggests that imbalances of the range of motion and strength of the internal and external rotation of the hip joint can affect knee adduction moments. The impact may exacerbate musculoskeletal disorders such as osteoarthritis of the knee. Therefore, further studies should be conducted to evaluate the effects of clinical interventions to correct these imbalances on the reduction of the knee adduction moments in patients with knee osteoarthritis.

고농도 도공의 건조조건이 도공지의 품질에 미치는 영향 (Effect of Drying Condition of High Solid Coating on the Coated Paper Properties)

  • 유성종;조병욱;이용규
    • 펄프종이기술
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    • 제42권1호
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    • pp.26-34
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    • 2010
  • Effects of drying condition (IR radiation) on the optical properties and the printability of coated paper were elucidated at various latex sizes and low and high coating color concentrations. It was found that the smaller latex provided better rheology and higher dry and wet pick strength than the larger one. The high solids coating resulted in higher paper gloss and smaller roughness than the low solids coating, even though the clay addition was reduced by 20 parts in the high solids coating. Increasing IR radiation prohibited binder migration into the base paper. Thus it improved binder distribution and decreased pores in the coated layer, resulting in the increased dry and wet pick strength and the improved printing gloss. On the other hand, the color trapping and ink set-off was impaired with increasing IR radiation. Print mottle index passed through a maximum with increasing IR radiation.

TBM 디스크 커터 마모 예측 모델 비교 연구 (A comparative study on the TBM disc cutter wear prediction model)

  • 고태영;윤현진;손영진
    • 한국터널지하공간학회 논문집
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    • 제16권6호
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    • pp.533-542
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    • 2014
  • 본 연구에서는 Gehring, CSM, NTNU 모델을 이용한 디스크 커터 수명 예측 방법과 각 모델이 가지는 특징을 살펴보았다. 디스크 커터 수명에 크게 영향을 주는 요소인 관입깊이, 암석의 일축압축강도, 마모지수의 변화가 각각의 예측 모델들에 미치는 영향을 분석하였다. 디스크 커터 수명은 1회전당 관입깊이에 선형적으로 증가하였고, 일축압축강도의 증가에 따라 감소하는 경향을 보였다. 마모지수인 CAI 값이 증가함에 따라 Gehring과 CSM 모델에서의 디스크 커터 수명은 감소하였으나, CLI 값이 증가할수록 NTNU 모델의 디스크 커터 수명은 증가하는 경향을 보였다. 그리고 실제 현장 자료를 이용하여 디스크 커터 수명을 상호 비교하였다.

제지 슬러지-목재 파티클 혼합보드의 내화성과 기계적 성질 (Fire Retardancy and Mechanical Properties of Paper Sludge-Wood Particle Mixed Board)

  • 손정일;이필우
    • Journal of the Korean Wood Science and Technology
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    • 제22권1호
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    • pp.54-65
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    • 1994
  • This research carried out to investigate the effects of inorganic materials in paper sludge on the thermal degradation and of paper sludge addition on physical and mechanical properties of paper sludge-wood particle mixed boards in comparison with unmodified particleboards. Also these unmodified particleboards and paper sludge-wood particle mixed boards were soaked in aqueous solutions of fire-retardant chemicals(diammonium phosphate and zinc chloride), and their fire retardancy were tested by oxygen index method and ISO ignition test to determine the feasibility of paper sludge, industrial waste, as a recyclable resource in fabrication of fire-resisting panels for building material. Since the redrying of fire-retardant treated particleboards and paper sludge-wood particle mixed boards were made by press drying method, this process was a simple and effective method. On the other hand, flexural bending strength and internal bonding strength were also analysed to evaluate mechanical properties through standard method.

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Improvement of Tetraplegia and Respiratory Symptoms with Complex Korean Medicine Treatment After Traumatic Cervical Spinal Cord Injury: A Case Report

  • Cho, Eunbyul;Woo, Hyeonjun;Cho, Nam geun
    • Journal of Acupuncture Research
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    • 제37권4호
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    • pp.275-280
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    • 2020
  • This study reports the effectiveness of traditional Korean medicine in treating tetraplegia and respiratory symptoms (including dyspnea) after traumatic cervical spinal cord injury surgery. The patient was treated with complex Korean medical treatment including electroacupuncture, pharmacopuncture, and herbal medicine. The manual muscle test (expanded Medical Research Council system) was used to measure the patient's muscle strength. The Korean version of the modified Barthel index and the functional independent measure were used to evaluate the patient's independence in performing daily activities. Following 2 hospitalizations and treatments, the patient's muscle strength improved > 4+ score for all joints, and the Korean version of the modified Barthel index and functional independent measure scores increased from 26 to 79 and 56 to 95, respectively. Symptoms of dyspnea, coughing, and sputum gradually improved and finally disappeared during hospitalization. This study suggests complex Korean medicine treatment may be effective in the rehabilitation of post-surgical cervical spinal cord injury patients.

토사면의 한계상태 설계법에 관한 연구 (A Study of Limit State Design Method in Soil Slope)

  • 정기훈;김종민;장범수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.129-136
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    • 2005
  • The deterministic analysis method has generally used to evaluate the slope stability and it evaluates the slope stability with decision value that is a representative value of design variables. However, one of disadvantages in the deterministic approach is there is not able to consider the uncertainty of soil strength properties, even though it is the biggest influential parameter of the slope stability. On the other hand, the limit state design(LSD) can take a consideration of uncertainties and computes both the reliability index and the probability of failure. LSD method is capable of overcoming the disadvantages of deterministic method and evaluating the slope stability more reliably. In this study, both the mean value and standard deviation of the internal land's representative soil strength properties applied to process the LSD method. The major purpose of this study is to gauge the general applicability of the limit state design in soil slope and to weigh the comparative validity of the proposed partial safety factor. In order to reach the aim of this study, the partial safety factor and resistance factor which totally satisfied the slope's overall safety factor were calculated by the load and resistance safety factor design (LRFD).

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원공공차를 가진 볼트 조인트와 핀 조인트의 강도평가에 관한 연구 (A Study on the strength of the Bolted Joint & Pin Joint with Hole Clearance)

  • 정강우;최진호;권진회
    • Composites Research
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    • 제25권6호
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    • pp.186-190
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    • 2012
  • 복합재료가 기계부품 및 항공기 구조물에 폭 넓게 적용됨에 따라, 복합재료 구조물에서 가장 취약한 복합재료 체결부의 설계는 매우 중요한 연구 분야로 대두되고 있다. 본 논문에서는 다양한 원공공차를 가지는 복합재료 볼트 조인트와 핀 조인트의 강도를 상호 비교하였다. 실험결과로부터 조인트의 원공공차가 $880{\mu}m$일 때 원공공차가 $0{\mu}m$ 보다 첫 번째 파손하중의 볼트 조인트는 24.2 %, 핀 조인트는 51.3 %의 강도저하가 발생되었다. 또한, 이에 대한 유한 요소 해석을 수행하여 파손지수를 계산하고 실험값과 상호 비교하였다.

폴리에스터 섬유의 저욕비염색공정에 있어서 직물특성과 균염성의 상관성 분석 (Correlation between Levelness and Fabric Characteristics for Low Liquor Ratio Dyeing Processes of Polyester Fibers)

  • 정종석;장경진;김태경;조성우;이용진;남창우
    • 한국염색가공학회지
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    • 제21권1호
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    • pp.59-66
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    • 2009
  • The seven kinds of polyester fabrics having different fabric characteristics were investigated in terms of their dyeing levelness under various liquor ratios. The levelness was evaluated statistically from color strength obtained at different sections of each piece of dyed fabrics. The color strength data were analyzed using a exponential decay function of 3 parameters, $y=y_0+ae^{-bx}$. The b value of the function was used as a index of sensitiveness of dependence on liquor ratio of levelness. The index, b value, showed a linear proportional relationship to thickness of fabrics. Average unlevelness of dyeings exhibited a inverse proportional relationship to both weight and thickness of fabrics.

석탄 저회로 제조한 인공토양의 기능성 건설재 적용 가능성 (Application for Functional Construction Materials of Artificial Soil Manufactured Using Coal Bottom Ash)

  • 김강덕;이영생
    • 한국세라믹학회지
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    • 제51권4호
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    • pp.300-306
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    • 2014
  • To recycle coal bottom ash(denoted here as CBA) generated from thermal power plants as a functional construction material, artificial soil(denoted as AS) containing CBA with dredged soil(denoted as DS) at a ratio(wt%) of 70 : 30 was manufactured by means of material engineering with sintering in a rotary kiln at $1125^{\circ}C$ using a green body formed via extrusion processing. The properties of the soil mechanics of the AS and the as-received CBA were analyzed and compared. Compaction testing results determined an optimum moisture content of the AS and CBA at 18%. During these tests, the maximum dry unit weights of the materials were similar, at 1.57 and 1.58 $t/m^3$, respectively. The compressive strength levels of the AS and CBA concrete specimens were 5.1 and 5.4 $t/m^3$, respectively, both of which increased after materials engineering processing. In a consolidation test, the compression index of the AS and CBA was found to be $0.114{\pm}0.001$ in both cases. The values were similar regardless of the materials engineering processes, but during the consolidation of AS, its coefficient was higher than that of the CBA materials.