• The Journal of Korean Physical Therapy
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• v.19 no.1
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• pp.23-31
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• 2007

Purpose: As a preliminary study, the purpose of this study was to examine the indirect estimation of the lumbar intervertebral disc size by two anthropometric methods, in order to compare these indirect methods with the direct analysis by radiological imaging. Methods: The wrist, elbow, knee, and ankle joint (both right and left) diameters were measured in 52 volunteers, and then intervertebral disc size was calculated using two anthropometric methods (Colombini and modified Colombini). The data were analysed with independent t-test to assess clinical usefulness. Results: When using right and left joint diameter, there was no significant difference in the estimation value of the L4-5 and L5-S1 intervetebral disc sizes. However, the study has shown that male subjects have significantly larger L4-5 and L5-S1 intervertebral disc sizes, compared with those of female subjects. In addition, disc sizes calculated by Colombini's formula were significantly larger than modified Colombini's formula. Conclusion: The indirect estimation of the intervertebral disc size by anthropometric method can be considered as a clinically useful method. However, further study should be conducted to compare anthropometric values with other radiological imaging.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.2
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• pp.129-138
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• 2013

Objectives : This study investigated the relationship between straight leg raising(SLR), valsalva test and size, position of lumbar disc herniation. Methods : We took SLR and valsalva test on 105 patients with lumbar disc herniation. According to the result of MRI findings, this study classified three groups of 105 patients with lumbar disc herniation, bulging, protrusion and extrusion. According to the position of lumbar disc herniation, 72 patients that were diagnosed protrusion and extrsuion were sorted 4 groups, lateral, lateral postero-lateral, central postero-lateral, central. The association size, position of lumbar disc herniation and SLR, valsalva test were analysed. Results : The bigger size of disc herniation, the more positive result of SLR and valsalva test, the lower angle of SLR test. There was not significant association between the position of lumbar disc herniation and the angle of SLR test. Conclusions : The SLR and valsalva test is an useful physical examination to speculate about the degree of lumbar disc herniation.

• Journal of Korean Neurosurgical Society
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• v.37 no.5
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• pp.336-339
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• 2005

Objective: The goal of this study is to establish the anatomical criteria of the normal and stenotic lumbosacral extraforaminal tunnel, and also to determine the effect of the pathologic intervertebral disc on the size of extraforaminal tunnel in the lumbosacral spine. Methods: MRI and CT scans were reviewed and classified into two groups: (1) 40 patients with normal discs at L5- S1 (Group 1) and (2) 43 patients that had undergone successful decompression surgery for extraforaminal entrapment at the lumbosacral region(Group 2). In these two groups, the following parameters were compared are compared: the distance between the disc margin and the ala (lumbosacral tunnel) on the axial MRI, and the posterior disc height at L5-S1 on the mid-sagittal MRI. Results: In the group 1, the mean distance of the lumbosacral tunnel on the axial MRI was $10.1{\pm}2.2mm$. The mean posterior disc height at L5-S1 was $7.4{\pm}1.7mm$ on the mid-sagittal MRI. In the group 2, the mean distance between the disc margin and the ala (costal process) was $1.6{\pm}1.3mm$ on the axial MRI. The average posterior disc height was $4.4{\pm}1.5mm$ on the mid-sagittal MRI. The posterior disc height and the size of the lumbosacral tunnel between the two groups were statistically different on the paired t-test (p<0.0001). However, the posterior disc height was not positively correlated with the size of the extraforaminal tunnel for group 2 (p=0.909). Conclusion: The extraforaminal stenosis was correlated to pathologic disc. However, the posterior disc height was not correlated to the size of the of the extraforaminal tunnel.

• Journal of Korea Foundry Society
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• v.10 no.6
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• pp.528-537
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• 1990

7XXX aluminum alloy powders produced by the self-manufactured rotating disc atomizer were investigated to determine the influence of the atomization parameters on the particle size distributions in air atmosphere. The particle size distributions are almost always bimodal with the dominant mode on the large particle size. Average powder size of 7XXX aluminum alloy is $74/{\mu}m~125/{\mu}m$ when melt is poured with the rate of 9g /sec at 730$^{\circ}C$ on a rotating disc of 30㎜ diameter at 6300rad/sec. The mass of finer particle increased when disc diameter, angular velocity, pouring temperature increased and pouring rate decreased. The powder shapes of bimodal change from acicular to tear-drop and from tear-drop to ligament with increasing powder size. Powder shape was determined by the atomization mechanism and oxidation in liquid state. Microstructure of powders appeared to be cell and cellular dendrite. The SDAS of Al-7.9wt%Zn-2.4wt%Mg-1.5wt%Cu-0.9wt%Ni Powders is $0.8{\mu}m~1.0{\mu}m$ for the powders of $size＋44{\mu}m~53{\mu}m$ and $1.6{\mu}m∼1.8{\mu}m$ for the powders of $size＋105{\mu}m~125{\mu}m$, repectively.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.285-287
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• 2010

Although the spontaneous disappearance or decrease in size of a herniated disc is well known, that of a large extruded disc has rarely been reported. This paper reports a case of a spontaneous regression of a large lumbar disc extrusion. The disc regressed spontaneously with clinical improvement and was documented on a follow up MRI study 6 months later. The literature is reviewed and the possible mechanisms of spontaneous disc regression are discussed.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.407-417
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• 2007

The purpose of this study is to determine whether change of the lumbar intervertebral disc diameters and size is a risk factor for development of lumbar disc lesion and this changes are associated with aging. The L4-5 and L5-S1 intervertebral disc diameters and size were measured in 50 normal subjects and 50 low back pain patients in the age range $20{\sim}60$ by MRI. The data were analysed with independent t-test to differentiation between normal subjects and low back patients. We also analysed with one-way ANOVA, Pearson correlation and simple linear regression to differentiate between different age ranges. This study has shown that older subjects of both normal and low back pain patients have significantly larger transverse diameters and sizes of the L4-5 and L5-S1 intervertebral disc, compared with those of younger subjects. In addition, low back pain patients's disc sizes were larger than normal subjects but there was statistically no significant difference. The measurement of the intervertebral disc size can be considered as a clinically useful method for diagnosis of the low back pain and aging of the intervertebral disc. However, further study should be conducted to establish normal value of intervertebral disc size on large number of subjects.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.144-151
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• 2014

Recently, according to the advances of vehicle manufacturing technology and the fuel-efficient vehicles, the weight of the vehicle body has been reduced and quietness of the vehicle has been increased. So that, as the emotional qualities of cars, such as NVH, are emphasized in recent years. Also required to be established of the effective measure for brake Judder. The Judder was caused by the increase in DTV by the uneven thermo metamorphosis of brake disc and the partial abrasion of disc. In this study, the disc aggression by friction materials was confirmed and the improving methods of friction materials in connection with the abrasive characteristics reviewed of $ZrSiO_4$ each particle size(under $3{\mu}m$, $5{\sim}10{\mu}m$ and over $15{\mu}m$). In addition, the study is institute make use of limit for $ZrSiO_4$ raw-material particle size and vol% in friction materials. At the result, the optimum size of $ZrSiO_4$ particles was confirmed about 5 to $10{\mu}m$.

• Computers and Concrete
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• v.22 no.4
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• pp.373-381
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• 2018

Hollow center cracked disc (HCCD) in Brazilian test was modelled numerically to study the crack propagation in the pre-cracked disc. The pre-existing edge cracks in the disc models were considered to investigate the crack propagation and coalescence paths within the modelled samples. The effect of particle size on the hollow center cracked disc (HCCD) in Brazilian test were considered too. The results shows that Failure pattern is constant by increasing the ball diameter. Tensile cracks are dominant mode of failure. These crack initiates from notch tip, propagate parallel to loading axis and coalescence with upper model boundary. Number of cracks increase by decreasing the ball diameter. Also, tensile fracture toughness was decreased with increasing the particle size. In this research, it is tried to improve the understanding of the crack propagation and crack coalescence phenomena in brittle materials which is of paramount importance in the stability analyses of rock and concrete structures, such as the underground openings, rock slopes and tunnel construction.

• Journal of the Korean Ceramic Society
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• v.44 no.10
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• pp.568-573
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• 2007

For the manufacturing lightweight fine aggregate, clay and waste material was formed by pelletizer. The fine aggregate of 1-5 mm diameter was formed by diameter 76 cm pelletizer disc. Pelletization variables were : (1) pelletizer disc angle, (2) speed of revolution of pelletizer, (3) added pelletization time. Green and sintered aggregate were measured specific gravity, absorption rate and average size. The optimum condition were found that the pelletization variables were angle at $70^{\circ}$, speed of revolution of pelletizer at 23.2 rpm, and water/solid ratio at 1/5. At these conditions, it was formed that fine aggregate green whose average size was $2.0{\sim}3.35mm$. Specific gravity and average size are increased with low angle of disc and fast revolution speed of disc. Specific gravity and average size were not distinctly influenced by added pelletization time. Sintered aggregate was distinctly influenced by properties of green.

• Journal of Veterinary Clinics
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• v.41 no.1
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• pp.1-7
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• 2024

The intervertebral disc is a crucial structure located between each vertebral body, except C1 and C2 and the fused sacral vertebrae, which provides cushioning and stability. However, sometimes these discs may bulge or extrude, causing painful conditions and various neurological problems such as ataxia, paresis, motor or sensorimotor paralysis. As a result, dogs affected by intervertebral disc disease (IVDD) can suffer a significant decrease in their quality of life. The main objective of this study was to provide comprehensive data on the body size of several IVDD-susceptible dog breeds commonly bred in South Korea, which could help develop supportive devices for IVDD patients. Using standardized measurements, the study aimed to design appropriate support tools, taking into account the mobility challenges faced by IVDD patients. The findings provide valuable data to improve the quality of life of patients with IVDD. In addition, it may lay the foundation for research to establish the correlation between body size and IVDD through future research.