• Title/Summary/Keyword: CM test

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A Study on Double - Punch Test for Tensile Strength of Concrete (Double-Punch Test에 의한 콘크리트의 인장강도 시험에 관한 연구)

  • 이우종;고재군
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.2
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    • pp.82-94
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    • 1988
  • The purpose of this study is to introduce the Double Punch test method which is an indirect testing method of tensile strength of concrete, and to compare with the tensile strength of concrete as determined by the split-cylinder test, a practical method for performing the Double Punch test to obtain the tensile strength of concrete is proposed and recommended for general use. In this study, the dimensions of cylindrical specimens used in the Double-Punch test were 15X30cm, 15X15cm, 10${\times}$(20cm, and 5${\times}$l0cm, and in the split-cylinder test were 15${\times}$(30cm, 15${\times}$(15cm, and 10${\times}$(20cm. And the diameters of loading punches used in the Double-Punch test were 1.5cm, 2.5cm, and 3.5 cm. The results obtained from tests are summarized as follows ; 1. In the split-cylinder test, the tensile strength of concrete by the linear elasticity theory is similar to that of plasticity theory. 2. Both split-cylinder test and Double-Punch test, tensile strength of concrete is increased with decreasing specimen size. This tendency is identical when the ratio of specimen diameter to height is 1: 2, but that tendency is quite different when the ratio is 1: 3. In the Double-Punch test, if specimen size is constant, by increasing the punch size, tensile strength of concrete is increased, too. 4. Using a 15 ${\times}$( 15 cm cylinder specimen and 3.5 cm diameter punch in the Double Punch test would give the most uniform and consistent result in tensile strength, and the result showed a gQod correlation with splitting tensile strength from 15 x 30cm specimen. 5. In order to obtain satisfactory results and to nuninuze variability, it is proposed that specimens of 15 cm in diameter and 15 cm in height with two 3.5 cm diameter punches should be used. It seems, therefore, reasonable tt) take f't=0.0024 P(kg / cm$^2$) as a working formula for computing the tensile strength in the Double Punch test for concrete.

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Stress Change Varying with Hole Place of RC Column (유공위치 변경에 따른 RC기둥의 내력변화에 관한 실험적 연구)

  • Son, Ki-Sang
    • Journal of the Korean Society of Safety
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    • v.21 no.2 s.74
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    • pp.70-79
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    • 2006
  • many plumbing system are needed in the ceiling of the building as it becomes advanced more and more. This leads to make effective space between ceiling level and slab less. Also, piping system is not suitably arranged and operated if it is bent around the columns which they are a lot. But this system can be more effective if it passes through the columns directly. Most people think that those columns should not be damaged with such as holes. But actually this is existed in a hotel building in switzerland. This study is to fing out how much capacity the columns become damaged and low using model size of $20cm{\times}30cm$ rectangular section, and 160cm long, in the structural test. it's compressive strength is focused on $240kg/cm^{2}$ design strength, commonly used in korea. Compressive test for them was done at Hanyang University using UTM one thousand tone(1000t) capacity. Variable numbers for the study are one hole of dia 3cm with distance 20cm or 40cm, two holes of dia 3cm with 20cm and 40cm distance, one hole of dia 5cm with distance 20cm and 40cm, two holes of dia 5cm with 20cm and 40cm distance, me eccentric hole with 20cm and 40cm distance, Normal(without hole). two test specimens of each variable are made for the test. ED5H20 capacity was 16.7% decreased, compared to normal one. While ED5H40 distant 40cm from the end of column top showed 19.5% capacity decrease, compared to normal one. Strain of ED5H20 diameter 5cm, in distance of 20cm form the top of the column was less 5% than the one of diameter 3cm. Finally, conclusions are that in case of hole diameter 3cm, located at 20cm from the end of the column top, capacity was decreased down to 3, percent only compared to the same diameter hole with 20cm distant from the end of it.

Effect of a Intentional Scapular Abduction on the Sit-and-Reach Test (의도적인 견갑골 외전이 Sit-and-Reach Test에 미치는 영향)

  • Kim, Suhn-Yeop;Chi, Chang-Yean;Kim, Kwang-Soo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.6 no.1
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    • pp.15-26
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    • 2000
  • Purpose : This study was done to examine the actual effect of the scapular position in these flexibility tests. The purpose of this study was to examine the differences between the measurement of SRT(Sit-and-Reach Test) without intentional abduction of the scapular (pre-test) and with intentional abduction of the scapular (post-test). The hypothesis is: 1. There is no differences in the SRT result of the pre-test and the post-test. 2. There is no differences in the HJA(Hip Joint Angle) result of the pre-test and the post-test. 3. There is no differences in the Spine Motion Test(SMT) result of the pre-test and the post-test. Method : The total 60 people (30 men, 30 women) were participated in this study. In the pre-test, the subjects were asked to sit on the examination table and try the SRT motion; and then the HJA, SRT and the SMT numerical values were taken. In the post-test. the subjects were instructed to intentionally bring the scapula outward from the midline; and the HJA, SRT and the SMT numerical values were taken. Result : In the pre-test. the SRT result averaged 34.17cm. and in the post-test. the SRT result averaged 36.68cm. The difference was about 2.81cm which showed a significant mean statistically (p<0.01). The measurement increased by 8.22%. The HJA was $85.9^{\circ}$ in pre-test, and it was $85.5^{\circ}$ in post-test. giving the $0.4^{\circ}$ differences. Therefore, it didn't have a statistical mean (p>0.05). The SMT value was 69.56cm in the pre-test. and it was 69.28cm in the post-test, about 0.28cm decreased. Therefore, it didn't have a statistical mean (p>0.05). SRT values and HJA values were correlated (p<0.01). SMT values and SRT values (p<0.01), and SMT values and HJA values(p<0.05) were each in counter correlation. Conclusion : The result of the SRT without intentional scapular abduction (34.17cm) and with intentional scapular abduction (36.68cm) showed a significant increase about 8.22% (p<0.01). In SRT, the effect of the intentional scapular abduction on SMT showed no significant means, the pretest value being 69.56cm and the post-test value being 69.28cm (p>0.05).

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Research on the Bacillus-fermented Enzamin Administration on Human NK Cell Activity and Bone Density of Hamster: A Pilot Study (Bacillus 발효액 Enzamin의 투여가 인체의 NK세포 활성도와 Hamster의 골밀도에 미치는 탐색연구)

  • Won, Ryu Seo;Fujii, Tokio;Lee, Hyung H.
    • Journal of Naturopathy
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    • v.7 no.2
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    • pp.63-69
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    • 2018
  • Purpose: The purpose of this study was to investigate the effects of Bacillus fermentation broth (ENM) on the human NK cell activity, and bone matrix density, matrix content and area of hamsters fed ENM. Methods: NK cell activity was tested, and bone mineral density were measured by x-ray. Results: NK cell activity was significantly higher in the control group (644.71 pg/ml) and in the test group (1796.37 pg/ml) (p<.004). Test groups were significantly increased by 1110.37 pg/ml in the pre-test and 1796.37 pg/ml in the post-test(p<.001). Behavioral observations after feeding ENM to hamsters showed normal behavior with no difference between control and test groups. The hamster body weight of the control was 106 g at the initial and final 27 days. In the test group, the initial weight was 96.6 g and the final 27 days was 114 g. No morphological changes were observed in the X-ray photographs of the hamster hind legs. The bone matrix density was 0.059 g/cm3 in control and 0.062 g/cm3 in the test, which was increased by 0.003 g/cm3. The bone matrix content was 0.175 g in the control and 0.196 g in the test. The bone area was 2.95 cm2 in the control and 3.19 cm2 in the test, which was increased by 0.19 cm2. In the autopsy, neither the control nor the test group showed any remarkable abnormality, and each organ was normal. Conclusions: It is thought that ingestion of ENM is useful for immunity enhancement.

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Evaluation of Strength Parameters of North-Cheju Basalt Rubble Using Large-Scale Triaxial Test (대형삼축압축시험을 이용한 북제주현무암 사석재의 강도정수 산정)

  • 정철민;김종수;채영수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.189-196
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    • 2002
  • According to the Korean Design Code for port and harbor facilaties, bearing capacity of rubble mound under eccentric and inclined load is calculated by the simplified Bishop method, and strength parameters are recommended to be c=0.2kg/$\textrm{cm}^2$ and ø=35$^{\circ}$for standard rubble if the compressive strength of parent rock is greater than 300kg/$\textrm{cm}^2$, quoting from research results by Jun-ichi Mizukami(1991), But this facts have never been certified in Korea because there was not large-scale triaxial test apparatus until 2000 in Korea. Firstly in Korea, the large-scale triaxial test (sample diameter, 30cm and height, 60cm) on the rubble originated from porous basalt rock in North-Cheju was accomplished. Then strength parameters for basalt rubble produced in North-Cheju are recommended to be c=0.3kg/$\textrm{cm}^2$ and ø=36$^{\circ}$if the compressive strength of parent rock is greater than 400kg/$\textrm{cm}^2$.

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Characteristic of a Soft Ground Behavior Subjected to Static and Dynamic Loads (A Study on the Model Test) (정하중 및 동하중이 작용하는 연약지반의 거동특성(비교모형실험))

  • Kim, Jong-Ryeol;Kang, Jin-Tae;Lee, Chi-Yeal;Part, Yong-Myun;Jeong, Jea-Hoon
    • Journal of the Korean Geotechnical Society
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    • v.24 no.1
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    • pp.111-118
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    • 2008
  • In the study a 2 dimensional model test was executed to grasp the effect of the taking load of equipments on the ground when improving a soft ground like dredging reclaimed ground. The static load and the dynamic load in the consolidated model ground was $0.02kg/cm^2,\;0.03kg/cm^2\;and\;0.04kg/cm^2$ respectively. After consolidating far two months by consolidation load of $0.02kg/cm^2,\;0.03kg/cm^2\;and\;0.04kg/cm^2$ respectively, the ultimate bearing capacity was $0.16kg/cm^2,\;0.19kg/cm^2,\;0.24kg/cm^2$ respectively. And the energy price of dynamic load test at the same point as the settlement of static load test indicated $E=336{\sim}945kg{\cdot}cm,\;E=252{\sim}780kg{\cdot}cm\;and\;E=323{\sim}727kg{\cdot}cm$ for each consolidation load. When the static load and the dynamic load operated at the same ground condition, the heaving quantity was bigger in the case of the dynamic load than in the case of the static load, and the horizontal displacement quantity the in the case of dynamic load was exhibited very deficiently compared to the quantity in the case of static load test.

A Study on the Explosion to Fire Transition Phenomena of Liquidfied Petroleum Gas (LP가스 폭발로부터 화재로의 천이에 관한 연구)

  • 오규형;이춘하
    • Journal of the Korean Society of Safety
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    • v.8 no.4
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    • pp.107-113
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    • 1993
  • Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm$\times$5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.

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A Study on Ease for the Skirt of Stretch Fabric according to the Fat Body Types (비만체형을 위한 신축성 직물 스커트의 여유분에 관한 연구)

  • 설경희;서미아
    • The Research Journal of the Costume Culture
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    • v.10 no.4
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    • pp.392-403
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    • 2002
  • The purpose of this study was to make clear reduction ratio due to the stretch ratio and to find out the ease for the patterns of stretch skirt according to fat body type to improve the aesthetics and wearing satisfaction. For this study, three college students were selected according to the fat body types; According to fat body types, 15 experimental skirt which were different each other in terms of the amount of ease on wait and hip, were made for the appearance test and wearing satisfaction test. The results from the study were as follows: 1. The results from the appearance test were as follows. For the ease on waist, W+2cm and W+0cm for fat body type were suggested for the best fit. For the ease on hip, H+2cm and H+0cm for fat body type were suggested for the best fit. 2. The results from wearing satisfaction test were as follows. W+2cm, H+2cm for fat body type were suggested for the best wearing satisfaction. 3. Based on the results from the above tests, the pattern reduction ratios for stretch skirt were as follows. pattern reduction ratio 0∼2.4% of waist, 1.9∼3.8% of hip for fat body type, were suggested for the appropriate reduction ratio for stretch skirt. 4. The result from this study for stretch skirt was as follows. For fat body type, W+2cm, W+0cm for waist and H+2cm, H+0cm for hip were appropriate for stretch skirt pattern. Therefore, different ease has to be applied to stretch skirt pattern according to the body parts, to make the skirt looks good, is appropriate for fat body type, and is satisfied with appearance and wearing satisfaction test.

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Comparison of Hydrodynamic Coefficients obtained through Implementation of Diverse Methods in Square Tank

  • Kang, Seunghyun;Yoon, Hyeon Kyu
    • Journal of Navigation and Port Research
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    • v.38 no.1
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    • pp.11-18
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    • 2014
  • To confirm whether the square tank at Changwon National University (CWNU) can be used for estimation of maneuverability, planar motion mechanism (PMM) test and circular motion (CM) test were performed for various conditions. PMM test can be implemented using an XY carriage and a yaw table in the square tank. However, sometimes test section is insufficient for PMM test owing to low length-breadth ratio of the tank. In addition, the speed of a towing carriage is also quite limited. Therefore, it would be useful if PMM test could be effectively performed diagonally, by establishing coupled control logic to drive three servomotors. In addition, Froude number dependency on the estimated hydrodynamic coefficients was checked. Furthermore, CM tests, which cannot be completed in a conventional linear towing tank, were performed, and its results were compared with the results of PMM test. The results of the PMM tests in the diagonal direction were consistent with the results of the test performed in the direction parallel to the sidewall. However, the results of the CM test were greater than those of the PMM test. This tendency was also observed in the results published at Ulsan University.

The Results of Various Vestibular Function Tests in Young Male Adult (장정에 시행한 몇가지 평가기능 검사성적에 대한 고찰)

  • 박찬일;추광철;노관택
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1972.03a
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    • pp.2.3-2
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    • 1972
  • The vestibular function test reveals the objective findings of the impairment of the vestibular labyrinth. It's purpose is based on the analysis of the findings and detect the location and etiology of the labyrinthine impairment. In the vestibular function test, the vestibulo-spinal reflex has the clinical significance upon the tonus of the striated muscles by the labyrithine stimulation and contribute to regulating the posture and the position, at rest as well as in motion. The vestibulo-spinal reflex must performe as one of the routine vestivular function test because it can be evoked in man by such weak stimuli to the labyrinth as cannot induce vestibulo-ocular reflex. Authors performed the vestibular function test such as one leg test, gait test, stepping test and vertical writing test to one hundred of healthy and young male adult and received the following results. Results 1. One leg test: In 30 seconds, the frequency of dropping the leg on the ground was between 0 to 3 times in Rt., and 0 to 5 times in Lt. The mean frequency was 0.48 times in Rt., and 0.68 times in Lt. 2. Gait test: In forward gait; the range of the deviation was distributed 0 to 100 cm and mean range was 22.5cm to the Rt., 26.1cm to the Lt. In backward gait; the range deviation was distributed 0 to 140cm and mean range was 35.4cm to the Rt., 33.0cm to the Lt. 3. Stepping test: In normal head position; forward movement war 93% and backward 5%. The angle of displacement deviated to the Rt. side in 36%, and Lt. in 50%. The angle of rotation deviated to the Rt. side in 53 %, and Lt. in 36%. The mean values: angle of displacement was 22.05 degrees, angle of rotation was 24.40 degrees, distance of displacement was 48.95cm. In backward head position; Forward movement was 94% and backward was 3%. The angle of displacement deviated in 34%, and Rt. in 55%, to the Rt. side The angle of rotation deviated to the Rt. side in 50%, and Lt. in 42%. The mean values; angle of displacement was 29.72 degrees, angle of rotation was 39.53 degrees, distance of displacement was 44.17cm. 44.17cm. 4. Vertical writing test: The angle of deviation was between 0 to 16 degrees in all cases, and was between 0 to 12 degrees in the cases of normal head position. The mean angle of deviation was between 4.15 to 5.76 degrees on each side. The direction of deviation to the Rt. side was 54~69%, Lt. was 25~40% and 3~7% was vertical without deviation.

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