• Title/Summary/Keyword: local resonance

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Variation of Harbor Oscillations in Yeongil Bay

  • Jeon, Min-Su;Lee, Joong-Woo;Jeong, Jae-Hyun;Yang, Sang-Yong;Jeong, Young-Hwan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.53-58
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    • 2006
  • Today, harbor oscillation problems are the most significant factor to consider when designing harbors serving very large ships. In coastal harbors, large vessels moored in the elastic hawsers are often displaced due to the resonance between long period waves and mooring systems. As a result, cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes extreme. The most significant harbor confronted with harbor oscillation problem in Korea is Pohang New port. Many cases of problems are being reported by the pilot association and the local office of MOMAF (Ministry of Maritime Affairs and Fisheries). However, it is difficult to prevent the arrival of long waves causing oscillation within this harbor. Moreover, the Korean government has already started a new port plan at the mouth of Yeongil Bay without addressing the problems that have occurred in Pohang New port. This study deals with the variation of harbor oscillation due to the construction of a 4.1 km breakwater at the bay mouth including the arrangement of the new berths. Numerical methods used are in fairly standard form from the extended mile slope equation. The obtained numerical results were compared with field measurement from the previous and this will bring a certain level of discussion and consideration of variation to the future port development.

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The Results of Cervical Nucleoplasty in Patients with Cervical Disc Disorder: A Retrospective Clinical Study of 22 Patients

  • Sim, Sung-Eun;Ko, Eun-Sung;Kim, Duk-Kyung;Kim, Hae-Kyoung;Kim, Yong-Chul;Shin, Hwa-Yong
    • The Korean Journal of Pain
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    • v.24 no.1
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    • pp.36-43
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    • 2011
  • Background: Nucleoplasty is a minimally invasive spinal surgery using a $Coblation^{(R)}$ technique that creates small voids within the disc. The purpose of this study was to evaluate the efficacy of cervical nucleoplasty in patients with cervical disc disorder. Methods: Between March 2008 and December 2009, 22 patients with cervical disc disorders were treated with cervical nucleoplasty after failed conservative treatment. All procedures were performed under local anesthesia, and fluoroscopic guidance and voids were created in the disc with the $Perc^{TM}$ DC Spine $Wand^{TM}$. Clinical outcomes were evaluated by the Modified Macnab criteria and VAS score at preprocedure, postprocedure 1 month, and 6 months. Results: Six patients had one, eight patients had two and eight patients had three discs treated; a total of 46 procedures was performed. Mean VAS reduced from 9.3 at preprocedure to 3.7 at postprocedure 1 month and to 3.4 at postprocedure 6 months. There was no significant complication related to the procedure within the first month. Outcomes were good or excellent in 17/22 (77.3%) cases. Postprocedure magnetic resonance imaging was acquired in two patients after two months showing morphologic evidence of volume reduction of protruded disc material in one patient but not in the other. Conclusions: Percutaneous decompression with a nucleoplasty using a $Coblation^{(R)}$ technique in the treatment of cervical disc disorder is a safe, minimally-invasive and less uncomfortable procedure, with an excellent short-term clinical outcome.

THEMIS Pi2 observations near dawn and dusk sectors in the inner magnetosphere

  • Kwon, Hyuck-Jin;Kim, Khan-Hyuk;Lee, Dong-Hun;Takahashi, K.;Park, Young-Deuk;Bonnell, J.W.
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.40.3-40.3
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    • 2010
  • The most frequently suggested source for Pi2 pulsations in the inner magnetosphere (L < 4) is standing fast-mode waves trapped in the plasmasphere (i.e., plasmaspheric resonances). They have been considered as the source of low-latitude Pi2 pulsations. The plasmaspheric resonance model suggests that compressional fast-mode waves can be detected at all local times inside the plasmasphere provided reflection of the wave energy is efficient. Until now, however, there are no reports about compressional Pi2s observed in the dayside inner magnetosphere. That is, there is longitudinal limit of inner magnetosphere. In February 2008, THEMIS probes were near dawn and/or dusk sides, which are the transition regions between the nightside and dayside, in the inner magnetosphere (L = 2-4) when low-altitude Pi2s were identified at Bohyun (L = 1.35) station in Korea. Using the THEMIS electric field data, we examined if Pi2s are excited by longitudinally localized disturbances. We found that compressional Pi2s having high coherence with a low-latitude Pi2 pulsation occur on dawnside. However, any compressional pulsations in the Pi2 frequency band were not detected on duskside. This indicates that compressional Pi2s disappear near the duskside. Our observations are discussed with spatial plasmaspheric structure and possible Pi2 mechanisms.

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Surgical Correction of Disfiguring Plexiform Neurofibroma Using an Anterolateral Thigh Free Flap (거대 층상 신경 섬유종 절제 후 전외측 대퇴부 유리피판술을 이용한 재건)

  • Kim, Seong-Ki;Roh, Si-Gyun;Lee, Nae-Ho;Yang, Kyung-Moo
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.679-682
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    • 2011
  • Purpose: Neurofibromas of neuroectodermal origin are commonly found in Von Recklinghausens disease or neurofibormatosis type 1. It is an autosomal dominant disease caused by mutation of the long arm of chromosome 17. It can present from small nodules to disfiguring giant tumor. Plexiform neurofibroma is benign in most cases, but it could be transformed into malignant tumor, which requires surgical excision. To cover the defects after the excision, a number of surgical correction methods are available. This study is to report a surgical correction of disfiguring plexiform neurofibroma using anterolateral thigh free flap for extensive defects after surgical excision of neurofibrona. Methods: Data of five neurofibroma patients with an average age of 39 including medical history, physical examination, computed tomography, and magnetic resonance imaging were checked. No disease other than neurofibroma were detected. Biopsy on the excised tissues was performed. The follow-up period was 7 to 27 months. Results: The average size of defects after complete excision of neurofibroma was $13{\times}10{\sim}25{\times}15$ cm. Defects were covered by anterolateral thigh free flap, while donor sites were covered by local flap, split thickness skin graft and regional flap. Throughout follow-up, there were no complication, relapse, or any abnormalities. Conclusion: Despite various surgical correction methods are applicable to defects after excision on disfiguring plexiform neurofibroma, coverage of massive defects is still challenging in plastic and reconstructive surgeon. We have made five successful cases of surgical correction of disfiguring plexiform neurofibroma using anterolateral thigh free flap.

Thermal-Induced Osteonecrosis of Adjacent Vertebra after Intradiscal Electrothermal Therapy

  • Kim, Soonjoon;Lee, Sun-Ho;Kim, Eun-Sang;Eoh, Whan
    • Journal of Korean Neurosurgical Society
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    • v.60 no.1
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    • pp.114-117
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    • 2017
  • A 42-year-old man was admitted to our hospital with complaints of low back pain and intermittent right thigh pain. Twelve weeks before admission, the patient received intradiscal electrothermal therapy (IDET) at a local hospital. The patient still reported low back pain after the procedure that was managed with narcotic analgesics. Follow-up magnetic resonance imaging (MRI) was performed, and his referring physician thought the likely diagnosis was spondylodiscitis at the L4-5 spinal segment with a small epidural abscess. At admission to our department, the patient reported aggravated low back pain. Blood test results, including the erythrocyte sedimentation rate and C-reactive protein levels, were slightly elevated. Biopsy samples of the L4, L5 vertebral bodies and disk were obtained. The material underwent aerobic, anaerobic, fungal, mycobacterial cultures and histologic examination. Results of all cultures were negative. Histologically, necrosis of the bone was evident from the number of empty osteocyte lacunae. In addition, there was no evidence of infection based on biopsy results. No antibiotic treatment was administered on discharge. Repeat computed tomography and MRI performed 12 months after IDET showed a bony defect in the L4 and L5 vertebral bodies, and a decrease in the size of the L4-5 intervertebral disc lesion. We report a case of lumbar vertebral osteonecrosis induced by IDET and discuss etiology and radiologic features.

Empirical Modeling of the Global Distribution of Magnetosonic Waves with Ambient Plasma Environment using Van Allen Probes

  • Kim, Kyung-Chan
    • Journal of Astronomy and Space Sciences
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    • v.39 no.1
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    • pp.11-22
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    • 2022
  • It is suggested that magnetosonic waves (also known as equatorial noise) can scatter radiation belt electrons in the Earth's magnetosphere. Therefore, it is important to understand the global distribution of these waves between the proton cyclotron frequency and the lower hybrid resonance frequency. In this study, we developed an empirical model for estimating the global distribution of magnetosonic wave amplitudes and wave normal angles. The model is based on the entire mission period (approximately 2012-2019) of observations of Van Allen Probes A and B as a function of the distance from the Earth (denoted by L*), magnetic local time (MLT), magnetic latitude (λ), and geomagnetic activity (denoted by the Kp index). In previous studies the wave distribution inside and outside the plasmasphere were separately investigated and modeled. Our model, on the other hand, identifies the wave distribution along with the ambient plasma environment-defined by the ratio of the plasma frequency (fpe) to the electron cyclotron frequency (fce)-without separately determining the wave distribution according to the plasmapause location. The model results show that, as Kp increases, the dayside wave amplitude in the equatorial region intensifies. It thereby propagates the intense region towards the wider MLT and inward to L* < 4. In contrast, the fpe/fce ratio decreases with increasing Kp for all regions. Nevertheless, the decreasing aspect differs between regions above and below L* = 4. This finding implies that the particle energy and pitch angle that magnetosonic waves can effectively scatter vary depending on the locations and geomagnetic activity. Our model agrees with the statistically observed wave distribution and ambient plasma environment with a coefficient of determination of > 0.9. The model is valid in all MLTs, 2 ≤ L* < 6, |λ| < 20°, and Kp ≤ 6.

Characterization of Bioactive Sialyl Oligosaccharides Separated from Colostrum of Indonesia Dairy Goat

  • Taufik, Epi;Arief, Irma Isnafia;Budiman, Cahyo;Wibisono, Yusuf;Noviyanto, Alfian
    • Food Science of Animal Resources
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    • v.42 no.3
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    • pp.426-440
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    • 2022
  • The bioactive functions of oligosaccharides from human milk have been reported by many studies. Many of oligosaccharides isolated from colostrum and/or milk of dairy animals have been reported to have similar chemical structures with those in human colostrum and/or milk. It has been proved by several studies that the oligosaccharides with similar chemical structure shared common bioactivities. Among domesticated dairy animals, bovine/cattle, caprine/goat, and ovine/sheep are the most commonly used species to isolate oligosaccharides from their colostrum and/or milk. Several studies on the oligosaccharides from goat colostrum and milk have revealed similar properties to that of human milk and possess the highest content of sialyl oligosaccharides (SOS) as compared to other ruminants. Indonesia ranks first in Association of Southeast Asian Nations (ASEAN) for goat milk production. Therefore, goat milk is the second most consumed milk in the country. The most reared dairy goat breed in Indonesia is Etawah Grade. However, oligosaccharides from Indonesia dairy animals including goat, have not been characterized. This is the first study to characterize oligosaccharides from Indonesia dairy animals. The present study was aimed to isolate and characterize oligosaccharides, specifically SOS from the colostrum of Etawah Grade goats by using proton/1H-nuclear magnetic resonance. The SOS successfully characterized in this study were: Neu5Ac(α2-3)Gal(β1-4)Glc (3'-N-acetylneuraminyllactose), Neu5Ac(α2-6)Gal(β1-4)Glc (6'-N-acetylneuraminyllactose), Neu5Gc(α2-3)Gal(β1-4)Glc (3'-N-glycolylneuraminyllactose), Neu5Gc(α2-6)Gal(β1-4)Glc (6'-N-glycolylneuraminyllactose), Neu5Ac(α2-6)Gal(β1-4) GlcNAc (6'-N-acetylneuraminyllactosamine) and Neu5Gc(α2-6)Gal(β1-4)GlcNAc (6'-N-glycolylneuraminyllactosamine). This finding shows that Etawah Grade, as a local dairy goat breed in Indonesia, is having significant potential to be natural source of oligosaccharides that can be utilized in the future food and pharmaceutical industries.

Experimental investigation on effect of ion cyclotron resonance heating on density fluctuation in SOL at EAST

  • Li, Y.C.;Li, M.H.;Wang, M.;Liu, L.;Zhang, X.J.;Qin, C.M.;Wang, Y.F.;Wu, C.B.;Liu, L.N.;Xu, J.C.;Ding, B.J.;Lin, X.D.;Shan, J.F.;Liu, F.K.;Zhao, Y.P.;Zhang, T.;Gao, X.
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.207-219
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    • 2022
  • The suppression of high-intensity blob structures in the scrape-off layer (SOL) by ion-cyclotron range of frequencies (ICRF) power, leading to a decrease in the turbulent fluctuation level, is observed first in the Experimental Advanced Superconducting Tokamak (EAST) experiment. This suppression effect from ICRF power injection is global in the whole SOL at EAST, i.e. blob structures both in the regions that are magnetically connected to the active ICRF launcher and in the regions that are not connected to the active ICRF launcher could be suppressed by ICRF power. However, more ICRF power is required to reach the full blob structure suppression effect in the regions that are magnetically unconnected to the active launcher than in the regions that are magnetically connected to the active launcher. Studies show that a possible reason for the blob suppression could be the enhanced Er × B shear flow in the SOL, which is supported by the shaper radial gradient in the floating potential profiles sensed by the divertor probe arrays with increasing ICRF power. The local RF wave power unabsorbed by the core plasma is responsible for the modification of potential profiles in the SOL regions.

Impact of 0.35 T Magnetic Field on Dose Calculation for Non-small Cell Lung Cancer Stereotactic Radiotherapy Plans

  • Jaeman Son;Sung Young Lee;Chang Heon Choi;Jong Min Park;Jung-in Kim
    • Journal of Radiation Protection and Research
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    • v.48 no.3
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    • pp.117-123
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    • 2023
  • Background: We investigated the impact of 0.35 T magnetic field on dose calculation for non-small cell lung cancer (NSCLC) stereotactic ablative radiotherapy (SABR) in the ViewRay system (ViewRay Inc.), which features a simultaneous use of magnetic resonance imaging (MRI) to guide radiotherapy for an improved targeting of tumors. Materials and Methods: Here, we present a comprehensive analysis of the effects induced by the 0.35 T magnetic field on various characteristics of SABR plans including the plan qualities and dose calculation for the planning target volume, organs at risk, and outer/inner shells. Therefore, two SABR plans were set up, one with a 0.35 T magnetic field applied during radiotherapy and another in the absence of the field. The dosimetric parameters were calculated in both cases, and the plan quality indices were evaluated using a Monte Carlo algorithm based on a treatment planning system. Results and Discussion: Our findings showed no significant impact on dose calculation under the 0.35 T magnetic field for all analyzed parameters. Nonetheless, a significant enhancement in the dose was calculated on the skin surrounding the tumor when the 0.35 T magnetic field was applied during the radiotherapy. This was attributed to the electron return effect, which results from the deviation of the electrons ejected from tissues upon radiation due to Lorentz forces. These returned electrons re-enter the tissues, causing a local dose increase in the calculated dose. Conclusion: The present study highlights the impact of the 0.35 T magnetic field used for MRI in the ViewRay system for NSCLC SABR treatment, especially on the skin surrounding the tumors.

Clinical Feasibility of CT Brain Perfusion in a Dog with Sellar Region Tumor

  • Minji Kim;Gunha Hwang;Jeongmin Ryu;Jiwon Yoon;Moon Yeong Choi;Joong-Hyun Song;Tae Sung Hwang;Hee Chun Lee
    • Journal of Veterinary Clinics
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    • v.41 no.3
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    • pp.178-182
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    • 2024
  • A 10-year-old spayed female Poodle was referred for blindness. On ophthalmic examination, loss of bilateral ocular pupil light reflex, visual loss, and right retinal detachment were confirmed at a local hospital. Magnetic resonance imaging (MRI) of the brain was performed to identify the optic nerve, optic chiasm, and brain disease. A sessile mass centered on the region of the optic chiasm was identified. The mass had iso- to hypointense on fluid-attenuated inversion recovery and T2-weighted images and mildly hypointense on T1-weighted images compared to the gray matter, with strong contrast enhancement. Peripheral edema was also identified. Computed tomography (CT) brain perfusion was performed to obtain additional hemodynamic information about the patient using a multislice CT. CT perfusion showed that the cerebral blood volume in the left temporal lobe region (13.4 ± 1.6 mL/100 g) was decreased relative to the contralateral region (19.9 ± 0.3 mL/100 g). The patient showed decreased appetite and consciousness one week after the CT scan with clinical symptoms worsened. The patient had seizure, tetraparesis, and loss of consciousness. It was euthanized one month later at the request of the owner. This report suggests that CT brain perfusion can provide additional hemodynamic information such as insufficient brain perfusion in sellar region tumor which can help assess potential complications and prognosis and plan treatment.