• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.73-82
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• 2023

In this study, the optimal method for injection of neutralizer to restraint the leakage of acid drainage in embankment structure composed of pyrite rocks is proposed. Finite Element Analysis was performed to examine the seepage effect caused by injection of neutralizer into the embankment structure. The diameter of the neutralizer injection hole was selected as 50cm, the interval space of injection ranged from 1m to 4m and the injecting pressure ranged from 100kPa to 220 kPa were applied for the numerical analysis. According to the analysis results, the saturation time of the whole embankment structure was shown to be fast at a relatively low injecting pressure in the case of injecting interval space of 1.0m and injecting pressure of 130kPa and in the case of injecting interval space of 2.0m and injecting pressure of 160kPa. When the interval space of injection for saturation of whole embankment structure is selected as 3m, various injection pressures can be applied from 130kPa to 190kPa, and the saturation time of whole embankment is similar regardless of the injection pressure. Therefore, the optimal method for injection of neutralizer considering economic efficiency was selected as injecting interval space of 3.0m and injection pressure of 130kPa.

• The Korean Journal of Pain
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• v.21 no.1
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• pp.57-61
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• 2008

Background: Shoulder joint injection is currently performed under fluoroscopic or computed tomography scan guidance. We performed this study to determine if an ultrasound guided shoulder joint injection through rotator cuff interval would have clinical usefulness. Methods: A total of 17 volunteers [12 women, 5 men; mean age 28 yr (23-32 yr)] received shoulder joint injection under multilinear ultrasound (5-10 MHz). Volunteers were positioned supinely on a table with their arm in a neutral position. The anterior shoulder region of the patient was sterilized using povidone iodine. A 24 gauge needle was introduced and directly visualized in real time as it passed obliquely from the skin surface to the inferior space of the biceps tendon. If there was little or no resistance to the injection, a contrast media (omnipaque) was injected and checked fluoroscopically. Results: Ultrasound guided shoulder joint injection through rotator cuff interval was successful in all cases. The average time taken for the procedure was $27.5{\pm}16.5sec$. The vertical distance from skin to the inferior space of the biceps tendon was $1.6{\pm}0.4cm$ and the distance of needle from the skin to the inferior space of biceps tendon was $2.8{\pm}0.6cm$. The procedure was well tolerated by all volunteers. Conclusions: Ultrasound guided shoulder joint injection through rotator cuff interval is an effective, rapid, and easy-to-perform injection technique. Ultrasound guided injection enables exact needle placement and avoids the use of both ionizing radiation and iodinated contrast material.

• Journal of Korean Neurosurgical Society
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• v.30 no.2
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• pp.163-167
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• 2001

Objective : Percutaneous vertebroplasty has recently been introduced as an interesting therapeutic alternative for the treatment of thoracolumbar vertebral body fractures in elderly persons with osteoporosis. The authors present the early results of this method. Method and Material : From July 1999 to April 2000, percutaneous transpedicular technique was used in 20 patients (2 men and 18 women) whose mean age was 67.5 years old(range 59-79) with painful vertebral compression(22) and burst(2) fractures. The interval between fracture and vertebroplasty ranged 1 day to 4 months. The procedure involved percutaneous puncture of the injured vertebra via transpedicular approach under fluoroscopic guidance, followed by injection of polymethylmetacrylate(PMMA) into the vertebral body through a disposable 11-guage Jamshidi needle. Result : The most common cause of fracture was slip down and the most frequent injured level was the twelfth thoracic spine. The procedure was technically successful bilaterally in 18 patients(9 thoracic and 15 lumbar spines) with an average injection amount of 7.7ml PMMA in each level. Seventeen(94.4%) patients reported significant pain relief immediately after treatment. Two leaks of PMMA were detected with postoperative CT in spinal epidural space and extravertebral soft tissue without clinical symptoms. Conclusion : Although this study represents the early results, percutaneous vertebroplasty seems to be valuable tool in the treatment of painful osteoporotic vertebral body fractures in elderly, providing acute pain relief and early mobilization.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.45-45
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• 2003

To evaluate remodeling of infarcted myocardium with contrast-enhanced MRI (co-MRI) at true end-diastole (ED) MRI was performed with a Gyroscan Intera (1.5 Tesla, Philips, Netherlands) in 13 patients with acute subendocardial myocardial infarction. The First exam was done 0-15 days (mean 5.2days) after symptom onset and the second exam 28-88days (mean 49 days) after the first exam. Ce-MRI encompassing the entire left ventricle was performed with a multi-shot, turbo-field-echo, breath-hold sequence and a non-selective, inversion prepulse 10 minutes after the intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg body weight. To allow the long TD, ECG synchronization should use two RR-intervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. Trigger delay time (TD) was adjusted to the RR-interval for true end-diastolic imaging. The other typical parameters were TR=5.4ms, TE=1.6ms, voxel size=1.37${\times}$1.37${\times}$10mm, k-space data segmented into 8 segments with 32 lines of segment per two cycles over 16 cardiac circles. The thickness of hyperenhanced myocardium and epicardially nonenhanced myocardium were followed.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.92-92
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• 2003

To evaluate remodeling of infarcted myocardium with contrast-enhanced MRI (co-MRI) at true end-diastole (ED) MRI was performed with a Gyroscan Intera (1.5 Tesla, Philips, Netherlands) in 13 patients with acute subendocardial myocardial infarction. The First exam was done 0-15 days (mean 5.2days) after symptom onset and the second exam 28-88days (mean 49 days) after the first exam. Ce-MRI encompassing the entire left ventricle was peformed with a multi-shot, turbo-field-echo, breath-hold sequence and a non-selective, inversion prepulse 10 minutes after the intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg body weight. To allow the long TD, ECG synchronization should use two RR-intervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. Trigger delay time (TD) was adjusted to the RR-interval for true end-diastolic imaging. The other typical parameters were TR=5.4ms, TE=1.6ms, voxel size=1.37$\times$1.37$\times$10mm, k-space data segmented into 8 segments with 32 lines of segment per two cycles over 16 cardiac cycles. The thickness of hyperenhanced myocardium and epicardially nonenhanced myocardium were followed.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.39-44
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• 1985

To assess the effect of post-operative pain control of upper abdominal surgery through lumbar epidural narcotic injection, the 3rd or 4th lumbar epidural puncture was done, and were injected 1mg, of morphine (Group I) or 10mg, of demerol (Group II) mixed with 10ml of normal saline into the epidural space, after operation of the cholecystectomy in 10patients and antrectomy and vagotomy, subtotal or total gastrectomy in 10patients. Time interval of the post-operative analgesic effect between morphine and demerol groups were compared. The results of this study were as follows: 1. In the group I, average analgesic duration was 29.4 hours. 2. In the group II, average analgesic duration was 4.0 hours. It is concluded that post-operative pain control of upper abdominal surgery through the lumbar epidural narcotic injection was effective, and morphine injection was more effective than demerol.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.537-537
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• 2013

Cyclotron-accelerated ion beams are used for various researches, such as nuclear physics, nuclear chemistry, biotechnology, and material sciences including radio-isotope production. Recently considerable applications are asked to the cyclotron development undertaken to meet user requirements of various ions'energies, intensities, and their pulsed beams. For instance, a cocktail beam acceleration technique rapidly changing the ion species and energies was developed to irradiating integrated circuit chips. Also a chopping system in a cyclotron injection line is considered for producing a pulsed ion beam with a relatively long period compared with that generated by the resonance frequency. For the research in neutron time-of-flight measurement, a single-pulsed beam with a repetition interval of the order of mili-seconds or longer is necessary to have a good resolution and to remove background events. In this paper a feasibility of pulsed beam with an external ion source is simulated by adopting a combination system of a chopper accompanying with a bunching stage in the injection line and an additional chopper after the exit of the cyclotron in order to produce beam pulses with a range of $1{\mu}s{\sim}1ms$ periods from a resonance RF cycle. The pulseperiod will be adjusted by chopping the number of beam bunches from the injected pulses in the injection line. However, the longer pulses will have reduced number of beam pulses and sacrificed beam currents. Because the beam users need an intense single pulsed beam, a careful tuning of the acceleration phase and a high-intense external ion source are necessary to achieve an intense single-pulsed beam from the cyclotron. It is essential to strictly match the acceleration phase of injected beams in the central region of the cyclotron to improve its efficiency. An effect of space charge at each pulse from the ion source will be also considered.

• The Korean Journal of Pain
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• v.25 no.4
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• pp.258-261
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• 2012

Posterior neck pain is a common complaint of patients in the pain clinic. The atlas (C1) burst fracture is known to be a cause of posterior neck pain and instability. Although the atlas burst fracture and instability can be discovered by plain X-rays which show lateral mass displacement or widening of the atlantodental interval, assessment of an atlas burst fracture can be difficult if there is no instability in the imaging study. Here we report a case of a 46-year-old female patient who had complained of sustained posterior neck pain for 6 months. Plain X-rays showed only disc space narrowing at C4/5 and C5/6, without any cervical instability. However, an unrecognized C1 lateral mass fracture was detected by CT and MRI. The patient's pain was then successfully treated after atlantoaxial joint injection with a C2 DRG block.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.117-122
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• 2006

In the geophysical monitoring to understand the change of subsurface material properties with time, the time-invariant static subsurface model is commonly adopted to reconstruct a time-lapse image. This assumption of static model, however, can be invalid particularly when fluid migrates very quickly in highly permeable medium in the brine injection experiment. In such case, the resultant subsurface images may be severely distorted. In order to alleviate this problem, we develop a new least-squares inversion algorithm under the assumption that the subsurface model will change continuously in time. Instead of sampling a time-space model into numerous space models with a regular time interval, a few reference models in space domain at different times pre-selected are used to describe the subsurface structure continuously changing in time; the material property at a certain space coordinate are assumed to change linearly in time. Consequently, finding a space-time model can be simplified into obtaining several reference space models. In order to stabilize iterative inversion and to calculate meaningful subsurface images varying with time, the regularization along time axis is introduced assuming that the subsurface model will not change significantly during the data acquisition. The performance of the proposed algorithm is demonstrated by the numerical experiments using the synthetic data of crosshole dc resistivity tomography.

• Journal of The Korean Astronomical Society
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• v.36 no.spc1
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• pp.37-44
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• 2003

In this paper, we review recent studies on the magnetic helicity changes of solar active regions by photospheric horizontal motions. Recently, Chae(200l) developed a methodology to determine the magnetic helicity change rate via photospheric horizontal motions. We have applied this methodology to four cases: (1) NOAA AR 8100 which has a series of homologous X-ray flares, (2) three active regions which have four eruptive major X-ray flares, (3) NOAA AR 9236 which has three eruptive X-class flares, and (4) NOAA AR 8668 in which a large filament was under formation. As a result, we have found several interesting results. First, the rate of magnetic helicity injection strongly depends on an active region and its evolution. Its mean rate ranges from 4 to $17 {\times} 10^{40}\;Mx^2\;h^{-1}$. Especially when the homologous flares occurred and when the filament was formed, significant rates of magnetic helicity were continuously deposited in the corona via photospheric shear flows. Second, there is a strong positive correlation between the magnetic helicity accumulated during the flaring time interval of the homologous flares in AR 8100 and the GOES X-ray flux integrated over the flaring time. This indicates that the occurrence of a series of homologous flares is physically related to the accumulation of magnetic helicity in the corona by photospheric shearing motions. Third, impulsive helicity variations took place near the flaring times of some strong flares. These impulsive variations whose time scales are less than one hour are attributed to localized velocity kernels around the polarity inversion line. Fourth, considering the filament eruption associated with an X1.8 flare started about 10 minutes before the impulsive variation of the helicity change rate, we suggest that the impulsive helicity variation is not a cause of the eruptive solar flare but its result. Finally, we discuss the physical implications on these results and our future plans.