• Title/Summary/Keyword: Experimental Size

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New Evaluation Method for The Particle Size and Morphology Via Change of Ground Particle During a Grinding Process (분쇄공정에서 변화된 입자크기 및 형상특성의 평가방법에 관한 새로운 제언)

  • Choi, Heekyu;Lee, Jehyun;Choi, Junewoo
    • Particle and aerosol research
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    • v.9 no.1
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    • pp.1-6
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    • 2013
  • New evaluation method for the particle size and morphology via change of ground particle during a grinding process was investigated. The grinding experiments were carried by a planetary ball mill. The relationship between the particle outline of the scanning electron microscopy photograph and measurement line, the measurement contact number was evaluated. The value of contact number decreased with the increase in the particle size of the ground sample, and varied with the experimental conditions. The value of contact number, which is related to the particle size of the raw sample, changed at the various experimental conditions.

Effects of Paljin-tang on Surgically Induced Endometriosis in Rats (팔진탕(八珍湯)이 자궁내막증(子宮內膜症)을 유발한 흰쥐에 미치는 영향)

  • Lim, Eun-Mee;Kwon, Ki-Rok;Lee, Mi-Jumg
    • The Journal of Korean Obstetrics and Gynecology
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    • v.19 no.3
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    • pp.83-94
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    • 2006
  • Purpose : This study examined effects of Paljin-tang on endometriosis. Methods : Sugically induced endometriosis in rats were given an oral dose of Paljin-tang for 40 days. The size of the ectopic uterine implants at the serosal wall and the concentration of progesterone, estradiol, tumor necrosis factor(TNF)-${\alpha}$ and interleukin(IL)-2, IL-4, IL-6, and IL-10 in the blood were examined and compared with the control group. Results : The size of the ectopic uterine implants in the experimental group was much smaller than of that in the control group. The concentration of estradiol was significantly lower in the experimental group than in the control group. The TNF-${\alpha}$, IL-4, IL-6 levels was significantly lower in the experimental group than the control group and IL-10 level was higher in the experimental group than the control group. The progesterone, IL-2 levels were similar in the experimental and control groups. Conclusion : These results indicate that Paljin-tang reduces the size of ectopic uterine implants at the serosal wall and inhibits the growth of ectopic uterine implants. This suggests that Paljin-tang is an effective treatment for endometriosis.

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Experimental Study on the Effect of Particle Size Distribution of Soil on the Liquefaction Resistance Strength (입도분포가 액상화 저항강도에 미치는 영향에 관한 실험적 연구)

  • Seo Kyung-Bum;Choi Mun-Gyu;Kim Soo-Il;Park Inn-Joon
    • Journal of the Korean Geotechnical Society
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    • v.21 no.7
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    • pp.13-20
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    • 2005
  • For experimental study on the effect of particle size distribution on the liquefaction resistance strength, particle size distribution curves of the dredged soil were investigated. In this process, four mean particle sizes and three uniformity coefficients were defined representatively and twelve representative particle size distribution curves which have different mean particle size and uniformity coefficient, were defined and manufactured by using the real dredged river soil. Cyclic triaxial tests and resonant column tests were carried out to analyze the effect of mean particle size and uniformity coefficient on the liquefaction resistance strength and dynamic characteristics.

An Experimental Study on Influence of Concrete Strength and Cover Size on Transfer Length of Prestressing Strand in Pretensioned Prestressed Concrete Members (압축강도 및 피복두께에 따른 프리텐션 부재의 전달길이 변화에 관한 연구)

  • 오병환;김동백;김의성;최영철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.355-358
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    • 1999
  • In recent times, large strands have become increasingly popular in the pretensioned prestressed industry and have found wide applications in varying geometries of sections. However, use of such elements and their behavior in several situations have been questioned with respect to anchoring of these strands in concrete. In addition, the experimental results available on bond are limited and information relating to large strands is rare. This study was conducted to determine the influence of some of the inadequately examined properties on transfer length of prestressing strand. The principle variables considered were strand size, concrete strength and clear bottom cover. The experimental results indicate clearly that concrete strength at transfer and cover size influence transfer length significantly. An attempt was made to suggest prediction equation for transfer length including above parameters.

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Assessment of Acoustic Iterative Inverse Method for Bubble Sizing to Experimental Data

  • Choi, Bok-Kyoung;Kim, Bong-Chae;Kim, Byoung-Nam;Yoon, Suk-Wang
    • Ocean Science Journal
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    • v.41 no.4
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    • pp.195-199
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    • 2006
  • Comparative study was carried out for an acoustic iterative inverse method to estimate bubble size distributions in water. Conventional bubble sizing methods consider only sound attenuation for sizing. Choi and Yoon [IEEE, 26(1), 125-130 (2001)] reported an acoustic iterative inverse method, which extracts the sound speed component from the measured sound attenuation. It can more accurately estimate the bubble size distributions in water than do the conventional methods. The estimation results of acoustic iterative inverse method were compared with other experimental data. The experimental data show good agreement with the estimation from the acoustic iterative inverse method. This iterative technique can be utilized for bubble sizing in the ocean.

Experimental human infection with Fibricola cratera (Trematoda: Neodiplostomidae)

  • Shoop, Wesley-L.
    • Parasites, Hosts and Diseases
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    • v.27 no.4
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    • pp.249-252
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    • 1989
  • Fibricola cratera is a strigeoid trematode indigenous to North America that, heretofore, was known only to infect wild mammals. Herein, it is reported that an experimental inoculation of a human volunteer produced a patellt infection that lasted 40 months. Symptoms of epigastric discomfort, loose stools and flatulence occurred over the first year of infection and ameliorated thereafter. Eggs per gram of stool were low (${\leq}2$) throughout the course of infection and were not detected by the standard technique of formalin-ether concentration. To monitor infection, the entire stool sample was examined each month after sieving through No. 10 (pore size 2 mm) and 100 (pore size $145{\;}{\mu\textrm{m}}$) sieves and collecting eggs on a No. 325 (pore size $45{\;}{\mu\textrm{m}}$) sieve. This is the first report of a North American strigeoid trematode capable of maturing in a human and is only the second species of strigeoid known to do so. The other species is F. seoulensis which has been implicated in 26 human infections in Korea.

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A Study on the Fabrication of Prototype Ultrasonic Machine Tool and It's Experimental Machining (실험용 초음파 가공기의 제작 및 가공실험에 관한 연구)

  • 김종광;서용위
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.930-933
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    • 2000
  • In this report experimental ultrasonic machine system has been fabricated and experimental machining has been performed using glass as a workpiece material. As grit size increases, material removal rate(MRR) was observed to be increased at decreased applied tool pressure on the workpiece, however at the higher applied pressure above $2-4\;kg/cm^2$ for smaller grit size, the MRR was not increased. Also better surface roughness was obtained for smaller grit size. Microchipping was observed from the microscopic examination and the pattern is similar to the iso-stress field where cracking is considered to be initiated near the surface.

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The Effect on the growth of landscaping trees by fixed trampling in brick paved under-surface soil physical properties -Sand bed's thickness & prticle size were setted by experimental variable factors (일정 답압시 보도블럭포장재 하부 토양물리성의 변화가 조경수 생육에 미치는 영향 - 포설모레 두께 및 립경을 실험변이 인자로 설정하여 -)

  • 조재현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.2
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    • pp.94-103
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    • 1997
  • The purpose of this study is to find out the effects of brick paved under-surface soil physical properties which are changed by fixed trampling. Thus, a sandy loam which is known as a profitable soil for plants is used an experimental soil to study the changes of the soil physical properties. It is related to sand bed's thickness & particle size which are settled by experimental variable factors. According to the variation of sand bed's particle size, bulk density and soil hardness at natural dryed soilcondition result in 0.075~2.00mm>2.00~5.00mm>2.00~8.00mm>5.00~8.00mm, and water content at natural dryed soil condition are observed being insensible change rate from the point that sand thickness is 30~40mm and more sand bed's thickness constructed by the variation of sand bed's thickness.

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An Evaluation on the Effect of Reversed Plastic Zone on the Fatigue Crack Opening Behavior under 2-D Plane Stress (2차원 평면응력 상태에서 되풀이 소성역이 피로균열 열림 현상에 미치는 영향에 관한 연구)

  • Choi, Hyeon-Chang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.8 s.239
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    • pp.1078-1084
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    • 2005
  • The relationship between fatigue crack opening behavior and the reversed plastic zone sizes is studied. An elastic-plastic finite element analysis (FEA) is performed to examine the opening behavior of fatigue crack, where the contact elements are used in the mesh of the track tip area. The smaller element size than reversed plastic zone size is used fer evaluating the distribution of reversed plastic zone. In the author's previous results the FEA could predict the crack opening level, which crack tip elements were in proportion to the theoretical reversed plastic zone size. It is found that the calculated reversed plastic zone size is related to the theoretical reversed plastic zone size and crack opening level. The calculated reversed plastic zone sizes are almost equal to the reversed plastic zone considering crack opening level obtained by experimental results. It can be possible to predict the crack opening level from the reversed plastic zone size calculated by finite element method. We find that the experimental crack opening levels correspond with the opening values of contact nodes on the calculated reversed plastic zone of finite element simulation.

A Study on the Development of Pants for Daily Use Appropriate for Korean School Girls aged 6 to 11 (학령기 여아를 위한 바지 원형 개발에 관한 연구)

  • Lee, Hyun-Ok;Cho, Kyeong-Sook
    • Journal of the Korean Society of Costume
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    • v.58 no.8
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    • pp.47-62
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    • 2008
  • The purpose of this study is to develop a basic sloper for pants that would be appropriate for young Korean school girls between the ages of 6 to 11 years old. Pants available in the apparel market for children do not properly correspond to the body size of the target consumer group. This research explores the characteristics of the body size of the group and also identifies problems of the conventional pants sloper that would be generally used for the production of children's apparel. Ultimately it presents a basic sloper for a possible use for manufacturing. The basic slopers for pants were collected from three different companies and were the examples used for this study. An experimental pants sloper was developed, reflecting the average body size of a nine year-old girl, which Is thought to be the master size for grading in children's wear Four different cotton prototype pants were made based on the three companies' slopers and the experimental one for evaluation of the fit and overall shape of the pants on subjects. The results revealed that the design, fit, and overall look of the experimental pants was superior to that of the opposing companies' product. After alteration of the experimental sloper, a basic pants sloper was finalized. The finalized pants sloper was determined at W/4+1cm for the front waist and W/4+2cm for the back, H/4+0.5cm for the front hip and H/4+1.5cm for the bark hip, and 73cm for its length with 15.5cm and 18cm for its front and back pants width at the bottom, respectively.