• 제목/요약/키워드: Physical density

검색결과 2,568건 처리시간 0.023초

저유동성 그라우팅 시공전후 지반의 물성변화 분석 (Analysis of the Physical Properties of Ground before and after Low Flowing Grouting)

  • 서석현;이정상;강원동;정의엽
    • 한국지반신소재학회논문집
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    • 제18권4호
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    • pp.115-127
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    • 2019
  • 본 연구의 대상 공법인 저유동성 그라우팅 주입공법은 모르타르를 주입재로 하여 비배출 치환원리에 의해 지중에 압입하는 공법으로서 지반의 밀도 증대효과를 기대할 수 있고 저소음, 저공해, 내구성 확보와 함께 경우에 따라서는 높은 주입 고결체의 강도를 이용한 기초파일로 사용할 수도 있다. 저유동성 주입공법으로 지반의 동적 특성이 향상됨을 확인하기 위하여 현장에서 시험시공을 실시하고 물리시험을 수행하였으며 코어에 대한 실내시험을 통해 지중에 형성된 개량체 품질을 확인하고 코어회수율 분석을 수행하였다. 밀도검층은 감마선의 컴프턴 산란을 이용하여 지층의 체적 밀도를 산정하였고, 음파검층은 시추공 내에서 음파발생 및 수신장치로 구성된 검층기를 이용하여 시추공 주변의 지반에 대해서 시험을 실시하였다. 그라우팅 전,후 물성변화(밀도검층, 음파검층)를 측정한 결과, 기본적으로 두 물성 모두 그라우트제 주입 후 물성이 증가하여 측정되었다. 다만, 그라우팅 후 속도 증가보다 밀도 증가의 변화 폭이 컸으며, 지반 밀도 측정 방법이 주입재의 충진 효과를 측정하는데 효과적이다. 재령 28일 후 채취한 시료로부터 강도 및 코어회수율을 측정하였으며, 시험결과 개량체의 확산 및 강도시험 결과가 설계기준을 만족시켜 내진성능보강을 만족한 것으로 확인하였다.

불안정 지지면에서의 동적 안정화 운동이 허리근육의 두께 및 밀도에 미치는 효과 (The effect of dynamic stabilization exercise on unstable surface on thickness, density of back muscle)

  • 한종만;박재철;김금숙;김현애
    • 한국산학기술학회논문지
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    • 제16권3호
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    • pp.1957-1963
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    • 2015
  • 본 연구의 목적은 불안정 지지면에서의 동적 안정화 운동이 배가로근과 뭇갈래근의 두께와 밀도 및 백색영역지수(white area index, WAI)에 미치는 영향을 연구하였다. 연구대상은 20대 성인 27명이며 세 그룹으로 나누어 각기 다른 면에서 동적 안정화 운동을 6주 동안 실시하여 실험 전 후에 배가로근과 뭇갈래근의 두께와 근육 밀도, 백색영역지수를 측정하였다. 그 결과 세 그룹 간 의미있는 차이를 보였다(p<.05). 반복측정분산분석(repeated ANOVA) 결과, 배가로근과 뭇갈래근의 두께가 시기별 차이에서 그룹 간 의미있는 차이를 보였으며(p<.05), 뭇갈래근의 근육 밀도와 백색영역지수의 그룹 간 비교결과 의미있는 차이를 보였다(p<.05). 결론적으로 불안정 지지면에서 허리부 안정화 운동의 효과에 의미있는 차이가 있었고 이 같은 결과는 허리안정화 운동에 대한 추후 연구에 기초 자료로 활용 가능할 것으로 보인다.

원예용 배지의 물리·화학성 분석을 위한 유럽의 표준방법 (Introduction to European Standard Methods for Physical and Chemical Analysis of Horticultural Substrates)

  • 김계훈;강지영
    • 원예과학기술지
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    • 제19권2호
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    • pp.179-185
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    • 2001
  • 원예용 배지의 물리화학적 특성을 파악하기 위해 전세계적으로 다양한 분석 방법이 사용되고 있다. 유럽은 배지 분석방법의 표준화 연구를 지속적으로 수행해왔다. 유럽표준화 위원회에서는 유럽표준방법으로 CEN methods를 최종안까지 제출하였으며 사실상 유럽표준 배지분석방법의 제정을 확립하는 단계에 있다. 물리적 특성 중 건물함량과 수분함량은 건조 후 분석하였고, 실험 가밀도는 일정한 부피에 채워진 시료의 무게로 측정하였다. 가밀도, 진밀도, 공극률, 액상, 기상, 부피 감소율은 double ring과 sand suction table이라는 장치를 사용하여 배지를 포화, 배수시킨 후 건조시켜 분석하였다. 화학적 특성 중 pH와 EC는 부피 기준 1:5로 침출하여 분석하였다. 유기물과 회분함량은 건조와 연소 과정을 통해 분석하였다. CEN methods는 유럽표준방법으로 확립을 앞두고 있으나 더 지속적인 연구가 필요할 것이다.

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편마비환자 양측 상지근에 대한 초음파 영상 비교 (Comparison of Ultrasonography on Both Sides of the Upper Extremity Muscle of Hemiplegic Patient)

  • 서삼기;이정우;윤세원
    • 대한임상전기생리학회지
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    • 제5권1호
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    • pp.1-10
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    • 2007
  • This study aims to comparison of ultrasonography on both sides of the upper arm of hemiplegic patient. The biceps brachii and deltoid muscle of ten subjects(4 men, 6 women) with stroke were scanned with ultrasonography at the muscle belly at rest at elbow angles of 90 deg. The echogenicity(densit, white area index; WAI) and muscle thickness of ultrasonography was examined using real-time B-mode ultrasonography with 7.5 MHz linear-array prob. In the biceps brachii muscle, MHz there were significant differences of thickness, density, and WAI between affected side and non-affected side. In the deltoid muscle, there were significant differences of thickness, density, and WAI between affected side and non-affected side. Both of the muscles, thickness of the affected side was thin than non-affected side and echogenicity(density, WAI) of the affected side was higher than non-affected side. This study showed that change of skeletal muscle architecture properties occurred in the upper arm of the affected side muscle of hemiplegic patient.

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뇌졸중 환자의 독립보행 유무에 따른 하지 근의 질적 특성에 대한 분석 (The Analysis on Quality Properties of Lower Extremity of Patient with Stroke by the Existence of the Independent Walking)

  • 이정우;서삼기;윤세원
    • 대한임상전기생리학회지
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    • 제5권1호
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    • pp.11-20
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    • 2007
  • The purpose of this study were to analysis on quality properties of lower extremity of patient with stroke by the existence of the independent walking. We recruited fourteen adults after stroke(7 male, 7 female; mean age, 64y) for our study. The subjects were divided into two groups; independent walking group(3 male, 3 female) and non-independent walking group(4 male, 4 female). We used in this study included a B-mode ultrasonography scanner with a 7.5 MHz linea probe. During the experiment, the subject was seated in the chair. The echogenicity(density, white area index; WAI) of the tibialis anterior and rectus femoris muscles were measured on both sides of the leg. In both of the density and WAI, the tibialis anterior muscle were significant differences between paratic side and non-paratic side, the independent walking and non-independent walking group. However, in both of the density and WAI of the rectus femoris muscle were only significant differences between paratic side and non-paratic side. This study showed that stroke and the independent walking have influenced on quality properties of lower leg. Especially, the independent walking has influenced on the tibialis anterior muscle.

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더블라셀파일 원단의 열처리조건에 따른 물리적 특성 변화에 관한 연구 (A Study on the Physical Properties of Double Raschel Pile Fabric according to Heat Treatment)

  • 손은종;박홍원;황영구
    • 한국염색가공학회지
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    • 제31권4호
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    • pp.288-297
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    • 2019
  • The specimens were heat treated at 180℃, 190℃, 200℃, 210℃ and 220℃ to observe the change of the physical properties of the double raschel pile fabric. The density, tensile strength, weight, elongation, dyeing characteristics, fabric surface morphology and cross sectional shape were observed by heat treatment temperature. Compared with untreated samples, weight, density and tensile strength were increased with increasing heat treatment temperature. No increase was observed at 220℃. In the case of elongation, it increased to 190℃ but thereafter it could not be observed. In the case of uprightness of brushed hair, it was observed that the gap between the yarns was narrowed and the density was increased and the straightness of the yarn and pile yarn was improved by widening the heat treatment temperature. As a result, it was observed that the uprightness was remarkably improved and the bulky properties was increased. It was also observed that the increase of the dyeability was observed with increasing the heat treatment temperature.

니트웨어 소재 특성에 다른 패턴 개발 연구 - 쉬프트 원피스 드레스를 중심으로 - (A Study on the Pattern Development of Knitwear According to Yarn Property - Focused on Shift One-Piece Dress -)

  • 윤혜준;송미령
    • 복식문화연구
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    • 제13권6호통권59호
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    • pp.896-909
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    • 2005
  • In need of studies on the kinds and structure of thread, the biggest variable factor in knitwear patterns, this study attempts: to examine the physical properties by thread type to basically establish systematic data in order to utilize various mixture and structure of yarn and to contribute to the development of optical patterns by building a systemic and scientific methods to produce knit wear patterns though a statistical analysis of the relation between the variations and physical properties. The results is as follows: with time, a feature of knit, which causes instability making it difficult to maintain the original shape, related to material properties, the weight and expansibility recovery rate have the greatest influence on the variation of wale lengths, though the amount varies by material. The variation of course contraction is closely related to density, the dense fabrics showing the highest values, due to the bust of the human body, the wale length variation of the front is greater than that of the back, by a regression analysis of material properties and the variations is obtained showing the weight, density and expansibility recovery rate have the greatest influence on the wale extension and course contraction of knit.

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정상노인과 뇌졸중 환자의 우세측과 비우세측의 골밀도 비교 (Compared to Bone Mineral Density between Dominant Side and Recessive Side in Normal Elderly and Stroke Patients)

  • 민동기
    • PNF and Movement
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    • 제11권2호
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    • pp.127-134
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    • 2013
  • Purpose : The purpose of this study of normal elderly and stroke patients by comparing the dominant side and recessive side was to evaluate the differents between each Methods : Thirty-two elderly participated in this study. They were classified two groups: stroke patients group and the normal elderly group. Outcome measures were: general characteristics and BMD. General characteristics included age, height, weight and body mass index. BMD was represented in the osteoporosis index, T-score and Z-score. The measurements of bone mineral density were evaluated on the calcaneus region of the dominant and recessive side, using OsteoPro. The data analyzed using SPSS 17.0 software and the Paired-sample T-test and the Independent-sample T-test Results : OI, T-score, Z-score showed no significant differences between dominant side and recessive side in normal elderly group. But stroke patients group showed OI, T-score, Z-score significant differences between paretic side and nonparetic side. Change score subtracted recessive side from dominant side was significant differences between stroke patients group and normal elderly group. Conclusion : There is positive relationship between physical activity and BMD in stroke patients. Therefore, improved physical activity can have a beneficial effect by reducing osteoporosis in stroke patients, considering a positive relationship between physical activity and BMD.

파워워킹과 플라자댄스가 중년 여성 고혈압 환자의 혈압감소 및 혈중지질에 미치는 영향 (Effect of brisk walking and square dancing on blood pressure reduction and blood lipid in middle-aged female patients with hypertension)

  • 류이회이;김정현;김옥자
    • 대한물리치료과학회지
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    • 제28권3호
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    • pp.76-87
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    • 2021
  • Background: The purpose of this study was to evaluate the effects of power walking and square dancing on middle-aged women with hypertension. Design: Randomized controlled Trial. Methods: 30 middle-aged women with hypertension were selected and divided into two groups. 15 cases in the control group received routine treatment, and 15 cases in the intervention group received community vigorous walking and square dancing intervention on the basis of routine treatment. The intervention time was 40-60minutes/day, 5days/week, total 16 weeks. total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), angiotensin II (Ang II), Leptin, blood pressure, and heart rate were measured. Results: Body weight, body mass index (BMI), TC, TG, LOW-density lipoprotein, angiotensin II, leptin, systolic blood pressure and heart rate were significantly reduced after power walking and square dancing (p<0.05). After the experiment, TC and TG in the experimental group were lower than those in the control group (p<0.05), while HDL was higher (p<0.05). Conclusion: The results of this study suggest that power walking exercises and square dances are significant effects on lipid mechanism and heart rate.

목공예적 가치평가를 위한 수종의 국내산 목재의 물리적 특성 평가 (Evaluation of the Physical Properties of Some Unused Domestic Woods Designed for Woodcraft Materials)

  • 장재혁;권성민;권구중;박병호;;김남훈
    • Journal of Forest and Environmental Science
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    • 제26권2호
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    • pp.131-136
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    • 2010
  • In an effort to evaluate the qualities of the unused woods designed for art materials, Yellow pine, Pitch pine, Suwon poplar, Platanus and Cherry grown in Korea has been investigated in the study. Physical and mechanical properties such as density, hardness, roughness, and abrasion of the woods were examined. Among the five species, Cherry wood showed the highest density in green, air-dried and oven-dried conditions. Hardness of Cherry wood was higher than those of Suwon poplar and Platanus. In softwoods, Pitch pine showed greater hardness than Yellow pine. Yellow pine and Platanus had the highest values of wood surface roughness. Abrasion value of cross, radial and tangential sections was the highest in Yellow pine and Suwon poplar. It has been concluded from the experiment that physical and mechanical properties such as density, hardness, roughness, and abrasion of the woods can be used as an indicator of the suitability for woodcraft material.