• 제목/요약/키워드: weight change rate

검색결과 821건 처리시간 0.027초

동결융해시험에 의한 사암 및 안산암의 풍화특성 평가 (Estimation of Weathering Characteristics of Sandstone and Andesite by Freeze-Thaw Test)

  • 강성승;김종인;오바라 유조;히라타 아츠오
    • 터널과지하공간
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    • 제21권2호
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    • pp.145-150
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    • 2011
  • 사암과 안산암에 대한 풍화특성을 살펴보기 위하여 동결융해 반복시험을 실시한 후, 두 암석에 대한 중량 감소율, 탄성파속도, 일축압축강도 등의 물성 변화를 측정하였다. 중량 변화의 경우 두 암석 모두에서 동결 융해 반복 횟수가 증가함에 중량이 감소하는 경향을 보였다. 특히 안산암에서는 중량 감소 경향이 시험편에 따라 매우 불규칙하게 나타났다. 탄성파속도 변화에 있어서 사암은 5%이상의 감소 경향을 보였으며, 안산암은 동결융해 반복시험 500 사이클까지 탄성파속도 변화가 거의 없다가 1000 사이클부터 5%이상의 감소 현상을 보였다. 이것은 안산암이 비교적 풍화에 강한 암석인 반면, 사암은 풍화받기 쉬운 암석인 것을 의미한다. 또한 안산암의 탄성파속도 변화 양상은 안산암의 중량 변화와 일치한다. 사암의 일축압축시험 결과에서 일축압축강도는 동결융해 반복시험 초기 사이클 구간에서 미미한 강도저하를 보이다 64 사이클부터는 불규칙한 경향을 나타냈다. 결과적으로, 중량 감소가 적은 암석 시험편일수록 강도저하율도 작게 나타났다.

세탁에 따른 안감의 물성변화에 관한 연구 (Change of Physical Properties of Lining Fabrics by Washing)

  • 최은희
    • 대한가정학회지
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    • 제17권4호
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    • pp.15-22
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    • 1979
  • This paper was studied changes of physical properties of Lining fabrics by washing and difference between dry method. I experimented four kinds of Lining fabrics for the sample . The analysis was performed by correlation coefficient analysis and significance tested between correlation coefficients. The results are summarized as follows : 1) Increasing rate of shrinkage tends to call high density and weight. 2) Rayon fabrics is shown the most high rate of shrinkage and decreasing strength by increasing washing times. 3) Drip dry makes little change of physical properties. 4) Polyester fabrics is little by washing times and dry method.

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Effects of Storage Environmental Conditions on Weight Loss, Whiteness Change, and Microbial Activity of Mushrooms (Agaricus bisporus)

  • Pai, Tongkun
    • Journal of Applied Biological Chemistry
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    • 제43권3호
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    • pp.161-164
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    • 2000
  • The effects of storage temperature and high relative humidity (RH) on the weight loss, color change, and microbial activity of a mushroom ('Sylvan' hybrid white) were investigated. The experiment was performed at three temperature (5, 10 and $15^{\circ}C$) and four different relative humidity levels (91, 94, 97 and 99%). The weight loss of the tested samples had a highly correlated linear relationship with storage time at each RH level during storage. Both the storage temperature and RH levels in the experiment had signigicant effects (p<0.05) on the weight-loss rate of the tested samples. The loss whiteness of mushrooms was not significantly affected (p>0.05) by RH ranges at the same temperature. No visible damage was caused by either bacteria or fungi in all samples during storage.

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Succinylcholine Chloride로 근이완된 견에 있어서 Doxapram Hydrochloride에 의한 회복효과 (Analeptic Effects of Doxapram after Succinylcholine Treatment in Dog)

  • 김명철
    • 한국임상수의학회지
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    • 제7권1호
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    • pp.407-414
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    • 1990
  • This study was performed to evaluate the effects of doxapram after succinylcholine treatment. Succinylcholine was administered intravenously at a dose rate of 0.07 mg per kg of body weight and then ten minutes after the injection of succinylcholine doxapram was administered intravenously at a dose rate of 2 mg per kg of body weight. The results obtained were as follows : 1. Recovery time in dog given doxapram after succinylcholine treatment was shortened comparing with control group. 2. The changes in respiratory rate revealed a maximal increase immediately after the injection of doxapram. Thereafter respiratory rate gradually decreased, and revealed normal levels 20 minutes after the injection of doxapram. 3. The changes in heart rate revealed a maximal increase immediately after the injection of doxapram. Thereafter heart rate gradually decreased, but remained above the levels of control group. 4. Although arrhysthmias were observed after treatment of succinylcholine, these were disappeared after doxapram treatment. And there was no another change on electrocardiograms.

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불소 고무복합체의 저온과 고온촉진노화 특성에 대한 비교 연구 (A Comparative Study on the Characteristics of Accelerated aging at Low and High Temperatures of the Fluorocarbon Rubber Composites)

  • 박정배;이범철;정윤석;박성한
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.915-922
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    • 2017
  • 내열 및 내유성 고무복합체 특성연구(The study on the thermal and oil resistance rubber composite), 2016.[6] 연구에서는 고온($150^{\circ}C$, $175^{\circ}C$, $200^{\circ}C$) 조건의 고온촉진노화를 통하여 불소고무 복합체의 수명을 예측하였다. 일반적인 고무제품은 온도, 습도, 오존, 빛, 유제, 기계 및 전기적 응력 등의 특성저하 인자에 따라 다른 특성을 나타낼 가능성이 있으며, 이러한 문제를 해결하기 위하여 "내열 및 내유성 고무복합체 특성연구"[6] 연구에서 얻어진 고온촉진노화에 의한 수명 예측값과 저온촉진노화간의 인장강도 변화율 및 신장률 변화율 그리고 부피 변화율, 무게 변화율, 두께 변화율 및 열전도도를 비교 검토하였다. 검토 결과, 요구 한계수명은 모두 만족하였지만 고온촉진노화 결과와 저온촉진노화 결과 간 변화율에서 약간의 격차를 보였다. 이러한 변화율 격차가 일어나는 원인은 고온촉진노화에서는 노화 시 불소고무의 주사슬 분해로 인하여 인장강도, 신장률 감소 및 부피, 무게, 두께 증가가 일어나는데 비해 저온촉진노화에서는 $80^{\circ}C$에서 불소고무의 지속적 경화반응으로 인하여 인장강도, 신장률 및 부피, 무게, 두께 변화가 적게 나타났을 것으로 판단된다.

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Minimum Row Weight and Polar Spectrum Based Puncture Polar Codes Construction Algorithm

  • Liu Daofu;Guo Rui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권8호
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    • pp.2157-2169
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    • 2023
  • In order to handle the problem that puncture patterns will change the position distribution of original information bits and frozen bits in polar codes, which affects performance of puncture polar codes further, a minimum row weight and polar spectrum based puncture polar codes construction algorithm (called PA-MRWP) is proposed in this paper. The algorithm calculates row weight of generator matrix and sorts the row weight in ascending order first. Next, the positions with the minimum row weight are selected as initial puncture positions. If the rows with the same row weight cannot all be punctured, polar spectrum based auxiliary puncture scheme is used. In sub-channels with the same row weight, rows corresponding to the polarized sub-channels with higher reliability are selected as puncture positions to construct puncture vector, and the reliability is calculated based on polar spectrum. It is actually a two-step selection strategy, the proposed minimum row weight puncture (MRWP) algorithm is used for primary selection and polar spectrum based auxiliary puncture is used for adjustment. Simulation results show that, compared with worst quality puncture (WQP) algorithm, the proposed PA-MRWP algorithm and Gaussian approximation-aided minimum row weight puncture (GA-MRWP) algorithm provide gains of about 0.46 dB and 0.29 dB at bit error rate (BER) of 10-4, respectively when code length N=400, code rate R=1/2. In addition, the proposed puncture algorithms improve the BER performance significantly with respect to quasi-uniform puncture (QUP) algorithm.

PET직물의 감량율에 따른 역학적 특성변화에 관한 연구(III) (A Study on the Mechanical Properties to the Weight Reduction Rate of PET Fabrics(III))

  • 홍성철;이희준;조대현;김승진
    • 한국염색가공학회지
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    • 제11권1호
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    • pp.1-8
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    • 1999
  • This study surveys the mechanical properties such as surface properties(MIU, MMD, SMD) to the weight reduction rate of PET fabrics. For this purpose, 12 kinds of satin and 18 kinds of plain weave fabrics are prepared with change of the physical properties of weft yarn(T.P.M., density, and denier). The weight reduction rate was 0%, 12%, 25%, and 30%. Coefficient of friction(MIU), mean deviation of friction(MMD), and geometrical roughness(SMD) of the fabrics were measured and discussed with wed twist, yarn linear density, weft fabric density and weave structures.

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체질 량 지수가 정상인 여성의 주관적 체형 인식이 체중변화에 미치는 영향 (The Effect of Subjective Body Type Recognition on Weight Change in Women with Normal BMI)

  • 박서연
    • 한국융합학회논문지
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    • 제9권4호
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    • pp.313-320
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    • 2018
  • 본 연구는 주관적 체형 인식이 체중 조절 행태와 체중 변화에 미치는 영향에 관하여 규명하고, 바른 정보와 교육의 필요성을 제시 하기위해 시행 되었다. 제6기(2013-2015년) 국민건강영양조사 원시자료를 활용하여 체질 량 지수가 $18.5-25kg/m^2$ 인 만 19세 이상 성인 여성 6,238명을 대상으로 분석한 결과, 교육 수준과 소득 수준이 높을수록 자신을 비만으로 인식하고 있었으며 전체 조사대상자에서, 체중 감소를 위해 운동과 식사량 감소를 가장 많이 선택하고 있었다. 체중 감소 노력 비율은 비만 체형 인식 군이 높았으나, 1년간 체중 변화에서 마름 체형 인식 군이 가장 높은 체중 감소 결과를 보였다(p< .001). 결과적으로, 주관적 체형 인식이 체중 조절 행태 뿐 만 아니라 체중 변화에도 영향을 미치고 있었다(p< .001). 따라서 건강한 체중 조절 행태에 대한 교육과 바른 신체 이미지, 건강한 체형인식에 대한 교육이 체계적으로 이루어져야 할 것이다.

절식요법의 체중감량효과와 체성분 변화에 대한 관찰 (The Clinical Study on the Effect of Reduction in Body Weight and the Change of Body Composition after Fasting Therapy)

  • 김성수;신현대;신승우
    • 한방비만학회지
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    • 제3권1호
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    • pp.25-35
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    • 2003
  • Objectives : This study was aimed to investigate the change of the reduction in body weight and the change of body composition after fasting therapy, Chulsikyopub, which was put into practice in Dept. of oriental rehabilitation medicine at Kyung Hee oriental hospital. Method : We measured body weight, body composition, and the degree of obesity 2 weeks after fasting therapy and 10 weeks after fasting therapy with body composition analyzer(Inbody 2.0). Statistical comparisons between pre-therapy group and post-therpay group were done by paired t-test and Wilcoxon's signed rank test. Results : 2 weeks after fasting therapy, body weight was decreased 7.33kg(9.18%), body fat was decreased 2.47Kg(7.24%), muscle weight was decreased 4.66kg(11.37%), body fat ratio was increased 1.08%, and body metabolic rate(BMR) was decreased 118.23kcal(8.22%). 10 weeks after fasting therapy, each of body weight and fat was decreased 10.4Kg, muscle weight was increased 0.3Kg(0.7%), body fat ratio was decreased 7.9%, and BMR was increased 6.8Kcal(0.47%). But muscle weight and BMR did not satisfy statistical significance. Conclusions : fasting therapy for 10 weeks reduced body weight and body fat statistically significant without loss of muscle weight and BMR.

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모형실험장치를 이용한 불포화토의 강우 침투특성 분석 (Analysis of rainfall infiltration characteristics for unsaturated soils using a column test equipment)

  • 박규보;채병곤;김경수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.736-742
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    • 2010
  • This study was conducted to characterize on the relationships of rainfall intensity and infiltration rate of rainfall dependent on unit weight change in the gneissic weathered soil by a column test equipment. In this study, volumetric water content and pore water pressure were measured using TDR sensors and tensiometers at regular time intervals. Rainfall conditions including continuous rainfall and repeated rainfall were selected in order to know the effect of antecedent rainfall. In the condition of rainfall intensity 20mm/h and the unit weights of soil as $1.35g/cm^3$, $1.55g/cm^3$ and $1.61g/cm^3$, average rainfall infiltration rate was $2.814{\times}10^{-3}cm/sec$, $1.969{\times}10^{-3}cm/sec$ and $1.252{\times}10^{-3}cm/sec$ respectively. The higher rainfall intensity and lower unit weight of soil, the faster average infiltration rate. Overflow in the column was happened except rainfall condition of rainfall intensity 20mm and soil unit weight $1.35g/cm^3$. Increasing the soil unit weight, overflowed water was increased and occurrence time was faster.

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