• Title/Summary/Keyword: weight change rate

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

  • Kang, Seong-Seong;Kim, Jong-In;Obara, Yuzo;Hirata, Atsuo
    • Tunnel and Underground Space
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    • v.21 no.2
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    • pp.145-150
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    • 2011
  • Variations of physical properties such as weight loss rate, wave velocity and uniaxial compressive strength after performing freeze-thaw cyclic test were measured in order to define weathering characteristics of sandstone and andesite. Weight change in specimens of the two rocks decreased with increasing the repetition number of freeze-thaw cyclic test. In particular, weight loss of andesite specimens was very irregular. P-wave velocity of sandstone specimens decreased more than 5%. On the other hand, P-wave velocity of andesite specimens do not vary up to 500 cycles and decreased more than 5% after 1000 cycles. This implies that the sandstone are easily weakened and loosened by weathering processes, while the andesite are relatively strong. In addition, the wave velocity changes of the andesite specimens coincident with the weight change. Uniaxial compressive strengths of the sandstone specimens slightly decreased at the early stage of the freezing-thawing cyclic test, then tended to be irregular after 64 cycles. In conclusion, the rock specimens showed smaller weight loss, less had lower strength reduction rate.

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

  • 최은희
    • Journal of the Korean Home Economics Association
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    • v.17 no.4
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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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    • v.43 no.3
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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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Analeptic Effects of Doxapram after Succinylcholine Treatment in Dog (Succinylcholine Chloride로 근이완된 견에 있어서 Doxapram Hydrochloride에 의한 회복효과)

  • Kim Myung-Cheol
    • Journal of Veterinary Clinics
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    • v.7 no.1
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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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A Comparative Study on the Characteristics of Accelerated aging at Low and High Temperatures of the Fluorocarbon Rubber Composites (불소 고무복합체의 저온과 고온촉진노화 특성에 대한 비교 연구)

  • Park, JeongBae;Lee, BeomCheol;Jeong, YoonSeok;Park, SungHan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.915-922
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    • 2017
  • The study on the thermal and oil resistance rubber composite, 2016. [6] predicted the lifetime of Fluorocarbon Rubber by accelerating aging at high temperature ($150^{\circ}C$, $175^{\circ}C$, $200^{\circ}C$). general rubber products are likely to exhibit different properties depending on the degradation factors such as temperature, humidity, ozone, light, emulsion, mechanical and electrical stress. To solve these problems, We compared the rate of change about tensile strength, elongation rate, volume change rate, weight change rate, thickness change rate, thermal conductivity in low temperature promoting aging on the basis of predictive lifetime of high temperature promoting aging. As a result of the review, the required life expectancy was satisfied, but there was a slight difference in the rate of change between the high-temperature promoted aging life result and the low temperature promoted aging life result. The cause was a reduction in "tensile strength / elongation" and an increase in "volume / weight / thickness" caused by the main chain decomposition of fluorine rubber due to aging at high temperature promoting aging. However, the low temperature promoting aging was caused by the curing reaction of fluorine rubber at $80^{\circ}C$. The tensile strength / elongation and volume / weight / thickness changes were small.

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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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    • v.17 no.8
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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.

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

  • 홍성철;이희준;조대현;김승진
    • Textile Coloration and Finishing
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    • v.11 no.1
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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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The Effect of Subjective Body Type Recognition on Weight Change in Women with Normal BMI (체질 량 지수가 정상인 여성의 주관적 체형 인식이 체중변화에 미치는 영향)

  • Park, Seo-Yeon
    • Journal of the Korea Convergence Society
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    • v.9 no.4
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    • pp.313-320
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    • 2018
  • This study was conducted to establish the effects of subjective body-forming perception on weight-controlling behavior and weight loss, and to suggest the need for proper information and education. Using the data from the National Health and Nutrition Examination Survey conducted in the 6th period (2013-2015), 6,238 women aged 19 and over who have a body mass index of $18.5-25kg/m^2$ were analyzed. As a result, the higher the level of education and income level, the higher they were perceived to be obese, the more they chose to lose exercise and diet in order to lose weight across the board. The weight loss effort rate was higher in the obese body type recognition group, but the body weight type was the highest in the one year body weight change group (p < .001). As a result, subjective perception of body shape affected not only weight control behavior but also weight change (p < .001). Accordingly, it is necessary to have a systematic education on healthy weight-controlling behaviors, proper body image, and healthy body type recognition.

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

  • Kim, Sung-Soo;Shin, Hyun-Dae;Shin, Seung-Uoo
    • Journal of Korean Medicine for Obesity Research
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    • v.3 no.1
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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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Analysis of rainfall infiltration characteristics for unsaturated soils using a column test equipment (모형실험장치를 이용한 불포화토의 강우 침투특성 분석)

  • Park, Kyu-Bo;Chae, Byung-Gon;Kim, Kyeong-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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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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