• The Korean Journal of Pain
• /
• v.22 no.1
• /
• pp.99-103
• /
• 2009

We studied the historical changes of intervertebral disc displacement using magnetic resonance imaging. The phenomenon of the spontaneous regression of herniated discs is well known. The case of a 40-years-old male presenting with a large disc herniation at L5-S1, experiencing severe sciatic pain, and having the straight leg raising test positive at 25 degrees is presented. The extruded disc was documented by clinical examination. He was treated conservatively with epidural steroid injection (ESI), medication, physical therapy and self-exercise and reevaluated in 10 weeks later, 30 and 1 year. Large extruded disc can be treated successfully by physical therapy with ESI. However, the degeneration and the dehydration of disc result in decrease of disc height. Consequently, the regression of extruded disc might have been due to the resorption and the dehydration.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.3C no.5
• /
• pp.165-170
• /
• 2003

This paper presents development of solid core suspension disc insulators (cap and cap suspension disc insulator) for replacing cap and pin suspension disc insulators in overhead transmission and distribution lines which expose to lightning discharges. By this means the punctured problem caused by steep front surge voltage created by lightning discharge on the lines can be solved. The solid core suspension insulator was designed and constructed based on the dimensions of conventional suspension disc insulators (cap and pin insulators). The insulators are made of alumina porcelain. The electrical and mechanical characteristics of the solid core suspension insulators were carried out. The puncture test was performed in the air by applying steep front impulse voltage with amplitude about 2.5 per unit of 50% flashover (CFO) of the insulator unit at negative standard lightning impulse $1.2/50\;\mu\textrm{s}$ with steepness up to $9200\;kV/\mu\textrm{s}$. The testing results show that solid core suspension disc insulators are not punctured eventhough the steepness of the steep front impulse voltage was increased up to $9200\;kV/\mu\textrm{s}$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.05a
• /
• pp.101-104
• /
• 2010

A bulkhead-type pulse separation device has been developed for the multi-pulse rocket motor. The design parameters of the pulse separation device were the shape of the rupture disc slit, welding conditions, and the implementation of the seal disc. The pneumatic tests of the fabricated pulse separation devices showed that the rupture pressure increased as the quantity of the rupture disc slit and welding strength increased and the seal disc was implemented.

• Journal of the Korean Society for Heat Treatment
• /
• v.21 no.2
• /
• pp.111-115
• /
• 2008

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1056-1061
• /
• 2003

CD-R disc drive is one of the basic options of personal computer today. In this trend, various CD-R discs can be purchased in every market. Even very low quality discs are in market too. Today's CD-R disc drive is being operated over 10,000 RPM. So the possibility of the disc fracture is growing faster. Sometimes, during the test of a new disc drive by various methods to confirm the quality of it, fracture of the disc happens. And it happens in end user's personal computer scarcely. In this reason, new methods to confirm the quality and the failure mechanism of the optical disc are studied in this paper.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.629-630
• /
• 2006

To investigate sliding friction and wear behaviors of WC-Co/WC-Co pairs containing different WC grain sizes, the ball-on-disc test in air were carried out, where WC grain sizes a $0.5\;{\mu}m$ (F.G.) and $1.5\;{\mu}m$ (C.G.). The wear volume of F.G. pin for F.G. pin/C.G. disc is larger than that of F.G. pin for F.G. pin/F.G. disc due to higher friction coefficient, and the surfaces after wear test are richer in oxygen compared to those before test. Furthermore, the wear debris, which is composed of nona-scale grain, after the wear test are remarkably richer in oxygen than to those before test.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.1055-1056
• /
• 2010

• Journal of Korean Neurosurgical Society
• /
• v.29 no.10
• /
• pp.1340-1344
• /
• 2000

Objective : A prospective biochemical assay of prostaglandin $E_2$ content in symptomatic lumbar disc materials was done in order to clarify the pathogenesis of lumbar radiculopathy. Patients and Methods : Forty-eight disc specimens were purified by a standard solid-phase extraction procedure and analyzed by an enzymelinked immunosorbent assay for prostaglandin $E_2$. Clinical and anatomic correlations were evaluated with analysis of variance and t-test. Results : Acute herniated lumbar disc diseases tended to be associated with a higher prostaglandin $E_2$ content than degenerative lumbar disc disease. Sequestered discs tended to be associated with a higher prostaglandin $E_2$ content than extruded discs, which also showed higher prostaglandin $E_2$ content than protruded ones. A sciatica and positive straight leg raising test appeared to be associated with a higher prostaglandin $E_2$ content than a negative test. Conclusion : This result suggests that the level of prostaglandin $E_2$ would be correlated with clinical symptom and sign in the inflammatory process of lumbar disc herniation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.481-487
• /
• 2011

This paper provides a comparison between finite element analysis results and test data of rupture disc. Rupture disc is safety device of high pressure equipment. Rupture disc of solid rocket motor is a device to control rupture pressure. Rupture discs were made of AISI 316L. By the elastic-plastic analysis, the stress limit of rupture discs were compared to the test results. The results can be used to control the rupture pressure by the change of the disc size.

• The Journal of Korean Physical Therapy
• /
• v.32 no.2
• /
• pp.80-87
• /
• 2020

Purpose: Some patients who have undergone surgery due to lumbar disc herniation still complain of leg pain and other abnormal sensations. Therefore, the study examined the effects of the neurodynamics on pain and other abnormal nerve sensations in post-operated patients with lumbar disc herniation. Methods: The participants of this study comprised 20 adults (10 males and 10 females) who were diagnosed with lumbar disc herniation. The subjects were classified into two groups of 10 patients each in the lower extremity neurodynamics (LEN) and lumbar stabilization exercise (LSE) groups. Each intervention was applied twice a day for one week and was composed of two different exercise patterns; one was applied by a therapist, and the other was performed by the patients themselves. The data were analyzed using assessment methods of Digital Infrared Thermal Imaging (DITI), Toronto clinical neuropathy scoring system (TCNSS), Sympathetic Skin Response (SSR) test, and Oswestry Disability Index (ODI) scale. Results: Significant differences in TCNSS, DITI, ODI scale were observed between the LEN and LSE group (p<0.01). On the other hand, there was no significant difference in the SSR test between pre and post-treatment (p>0.05). Conclusion: The results indicated that neurodynamics treatment is effective in pain reduction and abnormal sensations, such as leg muscle cramps, in post-operated patients with lumbar disc herniation.