• 제목/요약/키워드: physical change

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이온결합 화합물과 산의 용해 현상을 물리변화와 화학변화로 구분하는 문제에 대한 중·고등학교 과학교사들의 인식 조사 (A Survey of Secondary School Science Teachers’ Thinking on Classifying Phenomena Related to Dissolution of Ionic Compound and Acid into Physical and Chemical Change)

  • 백성혜;김선경
    • 대한화학회지
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    • 제46권6호
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    • pp.561-568
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    • 2002
  • 이 연구에서는 물리변화와 화학변화에 대한 중·고등학교 과학교사들의 인식을 조사하였다. 연구를 위해 중·고등학교 과학교사들에게 설문지를 투입하여 총 80명의 설문을 분석하였다. 과학교사들의 인식 조사 결과, 이온결합 물질이나 산이 물에 녹는 현상을 물리${\cdot}$화학변화로 구분하는 것에 대해 교사들은 다양한 견해를 가지고 있음을 알 수 있었다. 그리고 유사하거나 동일한 현상에 대해서도 문항에서 언급한 초점이 다를 경우 다른 변화로 판단하는 경향이 있었다. 즉, 응답에 일관성을 기지지 못하는 것으로 나타났다.

고랭지 영농방법이 비점원오염 물질의 유출과 토양의 물리적 변화에 미치는 영향 (The Impacts of Runoff the Nonpoint Source Pollution and Soil Physical Change for Mountainous Management Practice)

  • 최중대;강태영;김도찬
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1998년도 학술발표회 발표논문집
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    • pp.521-526
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    • 1998
  • This study was initiated to build runoff plots, install soil and water quality monitoring systems and collect background data from the plots and soils to assess runoff the nonpoint source pollution and soil physical change in mountainous soils. Eleven 3 $\times$ 15 m runoff plots and monitoring systems were installed at a field of National Alpine Agricultural Experiment Station to monitor soil physical change, and discharge of nonpoint source pollutant. Corn and potato were cultivated under different fertilizer, tillage and residue cover treatments. The soil has a single-layered cluster structure that has a relatively good hydrologic properties and can adsorb a large amount of nutrient. 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge.

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운동성 테이핑이 정상인의 요부근력 및 유연성에 미치는 영향 (The Effects of Kinesio taping on Lumbar muscle strength and Flexibility)

  • 윤나미;서연순
    • The Journal of Korean Physical Therapy
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    • 제13권3호
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    • pp.579-584
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    • 2001
  • The purpose of this study was to determine the effects of kinesio taping on lumbar muscle strength and flexibility. The samples for this study were 61 normal subjects(35 experimental group, 26 control group), aged 19 to 29 years. The data were analyzed by paired t-test. pearson and bivariate correlations. The results of this study were as follows : 1. The lumbar muscle strength was significant change in the experimental group(p<0.05). 2. The lumbar muscle strength was no significant change in the control group(p>0.05). 3. The flexibility was significant change in the experimental group and control group(p<0.05). 4. The lumbar muscle strength and flexibility were high associated in between session reliability(p<0.05).

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간섭 전류 치료의 자극부위에 따른 활력징후의 변화 (The Change of the Vital Sign by the Variables of Stimulated Areas in Interferential Current Treatment)

  • 박영한
    • 대한물리치료과학회지
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    • 제16권3호
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    • pp.1-9
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    • 2009
  • Background: The purpose of this study is to have examined the influence on the blood circulation by comparing the differences between stimulating the sympathetic ganglion and the muscle group among the stimulation variables in interferential current stimulation. Method: The object of the study is the twenties(M=8, F=12), who are in great condition and have no pathological report for the blood circulation influence. The intensity of the inferential current stimulation is the medium degree, 100 bps constant current, which is the comfort and degree to confirm the muscle contraction. The areas stimulated are the stellate ganglion area in the seventh cervical vertebrae and the forearm muscle area. Results: We have made sure that there is no change in blood pressure and pulse and that the change in the skin temperature occurred highly. Conclusion: In considering the change of the blood circulation in case of stimulation area by the inferential current stimulation, we have seen that stimulating the sympathetic ganglion area is more effective than stimulating muscle area directly.

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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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크로마토그램을 이용한 아스팔트시멘트의 노화형질 분석 (Analysis of Asphalt Cement Aging Characteristics Using Chromatogram)

  • 김광우;연규석;박제선
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1991년도 가을 학술발표회 논문집
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    • pp.1-4
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    • 1991
  • Relationship between againg and characteristic change of asphalt is not well known through asphalt rheolopy. Therefore, this study was conducted to evaluate characteristic change of asphalt cement due to againg based on experimental results of chromatogram and selected physical properties. Currently, three virgin asphalt cements were tested for physical properties and chromatograms before and after artificially conditioning for againg. Results in the current study showed that againg caused significant changes of physical properties and increase of larger size molecules and approximately corresponding reduction of smaller size molecule in asphalt cement molecular size distribution.

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만성 무릎 퇴행성관절염 환자의 Q각 변화에 따른 보행의 변화 (The Change of Gait as Q-angle in Chronic Knee Osteoarthritis Disease)

  • 채정병;조현래;하남진;김용훈
    • 대한물리의학회지
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    • 제5권1호
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    • pp.71-79
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    • 2010
  • Purpose : To investigate of gait change as Q-angle in chronic knee osteoarthritis patients. Methods : Participated osteoarthritis disease patients(n=16) and normal adults(n=16). gait measure was used by GaitRite and Q-angle measure was used by tape measur

Sport impact on the strength of the nanoscale protein tissues under the thermal condition

  • Xin, Fang;Mengqian, Hou
    • Advances in nano research
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    • 제13권6호
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    • pp.561-574
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    • 2022
  • The stability of protein tissues and protein fibers in the human muscle is investigated in the presented paper. The protein fibers are modeled via tube structures embedded in others proteins fibers like the elastic substrate. Physical sport and physical exercise play an important role in the stability of synthesis and strength of the protein tissues. In physical exercise, the temperature of the body increases, and this temperature change impacts the stability of the protein tissues, which is the aim of the current study. The mathematical simulation of the protein tissues is done based on the mechanical sciences, and the protein fibers are modeled via wire structures according to the high-order theory beams. The thermal stress due to the conditions of the sport is applied to the nanoscale protein fibers, then the stability regarding the frequency analysis is investigated. Finally, the impact of temperature change, physical exercise, and small-scale parameters on the stability of the protein tissues are examined in detail.

보의 설치에 따른 하상변동과 물리적 교란평가 분석 (Analyses of Riverbed Changes and Physical Disturbance Evaluations by Weir Installation in a Reach)

  • 최흥식;이웅희
    • 대한토목학회논문집
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    • 제34권4호
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    • pp.1203-1213
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    • 2014
  • 청미천의 일부구간을 대상으로 HEC-RAS를 이용하여 보의 설치 유무에 따른 수리 및 하상변동 특성을 분석하였다. 한국수자원공사(2008)에서 제시한 방법을 이용하여 물리적 교란을 평가하였다. 보의 설치에 따른 하상변동이 큰 구간에서의 물리적 교란점수는 낮게 나타났다. 보의 설치에 따른 하상변동과 그에 따른 물리적 교란영향 범위는 거의 일치하여 하상변동은 하천에서 물리적 교란을 야기하는 중요한 인자임을 확인하였다. 기존 보에 의한 교란의 영향이 없는 상류와 하류 지점에 추가적인 보를 설치할 때는 일정구간에 보의 설치 이전과 유사한 교란점수로 나타나 추가적인 하천교란이 발생하지 않았다. 교란의 영향범위 상류와 하류의 끝단에 추가적인 보를 설치한 경우 전 구간에 걸쳐 교란의 영향 나타났다. 물리적 교란 영향범위가 중첩되도록 상류와 하류에 추가적인 보를 설치한 경우 물리적 교란양상의 중첩으로 전 구간의 교란점수는 매우 낮게 나타났다. 따라서 하천에서 보의 설치는 하상변동과 교란의 영향범위보다 충분히 떨어진 위치에 설치할 때 하천의 물리적 교란을 최소화할 수 있다.

Modeling of Grade Change Operations in Paper Mills

  • Ko, Jun-Seok;Yeo, Yeong-Koo;Ha, Seong-Mun;Lim, Jung-Woo;Ko, Du-Seok;Hong Kang
    • 펄프종이기술
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    • 제35권5호
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    • pp.46-52
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    • 2003
  • In this work we developed the closed-loop model of a paper machine during grade change with the intention to provide a reliable dynamic model to be used in the model-based grade change control scheme. During the grade change, chemical and physical characteristics of paper process change with time. It is very difficult to represent these characteristics on-line by using physical process models. In this work, the wet circulation part and the drying section were considered as a single process and closed-loop identification technique was used to develop the grade change model. Comparison of the results of numerical simulations with mill operation data demonstrates the effectiveness of the model identified.