Recently, Lee et al reported a new grading system for the lumbar spinal foraminal stenosis. They considered the type of stenosis, the amount of fat obliteration, and the presence of nerve root ...compression. Our aim was to evaluate whether a new MR imaging grading system correlated with symptoms and neurologic signs and could replace the previous grading system.
We examined 91 patients (M/F = 49:42; mean age, 50 years) who visited our institution and underwent MR imaging of the L-spine and were evaluated by 2 musculoskeletal radiologists. The presence and grade of lumbar foraminal stenosis at the maximal narrowing point was assessed according to the new grading system suggested by Lee et al (Lee system) and the Wildermuth grading system (Wildermuth system). Results were correlated with clinical manifestations and neurologic physical examination. Statistical analysis was performed by using κ statistics, categoric regression analysis, and nonparametric correlation analysis (Spearman correlation).
Interobserver agreement in the grading of foraminal stenosis between the 2 readers was substantially correlated (κ of Lee system = 0.767, κ of Wildermuth system = 0.734). The Rs for reader 1 and reader 2 between the Lee system and the Wildermuth system were 0.880 and 0.885, between Lee system and PNM were 0.715 and 0.604, and between the Wildermuth system and PNM were 0.800 and 0.680. For patients younger than 50 years of age, the R between the Lee and Wildermuth systems was higher than that for patients 50 years or older, but the Rs between the grading system and PNM were lower in the younger group than in the older group. The Rs of the Wildermuth system with PNM were higher in the older group than in the younger group; the differences between the Rs of the Lee system with PNM and the Wildermuth system with PNM were higher in the older group (0.016 young versus 0.130 old and 0.008 versus 0.107).
Interobserver agreement of the Lee system was slightly higher than the Wildermuth system and substantially correlated. Both systems are good for evaluation of lumbar spinal foraminal stenosis, but the Lee system showed slightly better interobserver agreement and good clinical correlation in the younger group of patients.
Aim To evaluate the accuracy of magnetic resonance imaging (MRI) findings in chronic lateral ankle ligament injury in comparison with that of surgical findings. Materials and methods Forty-eight ...cases (25 men, 23 women, mean age 36 years) of clinically suspected chronic ankle ligament injury underwent MRI studies and surgery. Sagittal, coronal, and axial, T1-weighted, spin-echo, proton density and T2-weighted, fast spin-echo images with fat saturation were obtained in all patients. MRI examinations were read in consensus by two fellowship-trained academic musculoskeletal radiologists who evaluated the lateral ankle ligaments, including the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) without clinical information. The results of the MRI studies were then compared with the surgical findings. Results The MRI findings of ATFL injury showed a sensitivity of detection of complete tears of 75% and specificity of 86%. The sensitivity of detection of partial tears was 75% and the specificity was 78%. The sensitivity of detection of sprains was 44% and the specificity was 88%. Regarding the MRI findings of CFL injury, the sensitivity of detection of complete tears was 50% and the specificity was 98%. The sensitivity of detection of partial tear was 83% and the specificity was 93%. The sensitivity of detection of sprains was 100% and the specificity was 90%. Regarding the ATFL, the accuracies of detection were 88, 58, 77, and 85% for no injury, sprain, partial tear, and complete tear, respectively, and for the CFL the accuracies of detection were 90, 90, 92, and 96% for no injury, sprain, partial tear, and complete tear, respectively. Conclusions The diagnosis of a complete tear of the ATFL on MRI is more sensitive than the diagnosis of a complete tear of the CFL. MRI findings of CFL injury are diagnostically specific but are not sensitive. However, only normal findings and complete tears were statistically significant between ATFL and CFL ( p < 0.001).
Infants grow rapidly, which causes the SCM to thicken physiologically. Therefore some cases of physiologically-thickened SCM can be confused with a poor response to physical therapy. There have been ...only a few quantitative ultrasonographic studies on the clinical outcome of rehabilitation for CMT. Our aim was to evaluate whether a new sonographic assessment method that uses the muscular thickness ratio of the SCM can help quantify the outcome of rehabilitation therapy for patients with CMT.
We evaluated 48 patients (male/female, 17:31; mean age, 3.9 months) who were diagnosed with CMT and who underwent initial and follow-up sonography. The ratio of the thickness of the involved SCM to the thickness of the intact SCM (SCM thickness ratio) was calculated. A scoring system based on the range of motion of the neck was used to assess clinical improvement. The correlations between clinical improvement and the thickness of the involved muscle, the difference in involved muscle thickness, the SCM thickness ratio, and the difference in the SCM thickness ratio were evaluated with Spearman rank correlations.
Follow-up Cheng scores were higher than initial scores; this difference indicates clinical resolution (follow-up, 4.90; initial, 3.38). The SCM thickness ratio at follow-up was lower than that at the initial evaluation (follow-up, 1.29-1.34; initial, 1.65-1.77). Intra- and interobserver agreements were excellent. Most variables were moderately correlated with clinical improvement (correlation coefficients, 0.36-0.509). R1 showed the highest correlation with clinical improvement (0.481 and 0.509), followed by the initial maximal thickness of the SCM (0.434 and 0.488). ΔP (P1-P2) and ΔR showed similar correlation coefficients with clinical improvement.
Measurement of the SCM thickness ratio appears to overcome the problem of a false-positive diagnosis of clinical aggravation of CMT resulting from physiologic growth. R1 and ΔR are accurate objective measurements, which can be used in the management of CMT.
Methane and N2O fluxes during composting of solid swine manure were studied using three aeration systems being, forced aeration (FA), wire mesh (WM) and turnover (TO) and no aeration, for 85d to ...suggest strategies of mitigating GHG emissions during composting. Manure was collected from a swine research barn by a scraper system and mixed with sawdust as a bulking agent. The manure sawdust mixture was placed in linear low density polyethylene containers for each composting method. A steady state chamber covering each container was used to measure CH4 and N2O fluxes during composting in order to sample temporal and spatial heterogeneous fluxes. Air samples were continuously analyzed for CH4 and N2O by a high frequency trace gas analyzer. Mean CH4 fluxes from FA, WM, TO, and no aeration were 5.2, 3.8, 7.5, and 34.6μg/m2/s, respectively. Mean N2O fluxes from FA, WM, TO, and no aeration were 1.6, 3.1, 7.9, and 11.4μg/m2/s, respectively. Ratios of CO2-equiv. emitted from FA, WM, TO and no aeration were 0.14, 0.24, and 0.59, respectively. Nitrous oxide was the main contributor to CO2-equiv. fluxes. The FA system had the lowest emissions, but WM had the advantage of not requiring electricity for aeration.
This paper is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors: K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.
The aim of this study was to evaluate the success rate in ultrasonography-guided ethanol ablation (EA) of benign, predominantly solid thyroid nodules and to assess the value of colour Doppler ...ultrasonography in prediction of its success.
From January 2008 to June 2009, 30 predominantly solid thyroid nodules in 27 patients were enrolled. Differences in the success rate of EA were assessed according to nodule vascularity, nodule size, ratio of cystic component, amount of injected ethanol, degree of intranodular echo-staining just after ethanol injection and the number of EA sessions.
On follow-up ultrasonography after EA for treatment of thyroid nodules, 16 nodules showed an excellent response (90% or greater decrease in volume) and 2 nodules showed a good response (50-90% decrease in volume) on follow-up ultrasonography. However, 5 nodules showed an incomplete response (10-50% decrease in volume) and 7 nodules showed a poor response (10% or less decrease in volume). Statistical analysis revealed a significant association of nodule vascularity (p=0.002) and degree of intranodular echo-staining just after ethanol injection (p=0.003) with a successful outcome; however, no such association was observed with regard to nodule size, ratio of cystic component, amount of infused ethanol and the number of EA sessions. No serious complications were observed during or after EA.
The success rate of EA was 60%, and nodule vascularity and intranodular echo-staining on colour Doppler ultrasonography were useful in predicting the success rate of EA for benign, predominantly solid thyroid nodules.
•Efforts have been made to obtain high-quality vacuum condition for the KSTAR NBI.•The neutral beam injector requires the high vacuum pumping system which is capable of maintaining the vacuum ...pressure in the 10−5 mbar range during neutral beam pulses.•The detailed engineering design, fabrication, and installation results of large condensation cryo-pumps and vacuum sub-components were explained.•We present the commisioning results and status of the KSTAR NBI-2, and the concept design and operational characteristics of the vacuum pumping system on the KSTAR NBI-2.
The Korea Superconducting Tokamak Advanced Research (KSTAR) Neutral Beam Injection (NBI) system is designed to provide additional plasma heating and current drive for high performance and long pulse operation of the KSTAR tokamak using two co-current beam injection systems. Each neutral beam injection system is designed to consist of three ion sources, and each ion source is designed to deliver more than 2.0 MW of deuterium neutral beam power for the 100 keV beam energy. Consequently, the final goal of the KSTAR NBI system is to inject 12 MW of deuterium beam power for the long pulse operation of the KSTAR. The first NBI (NBI-1) has been installed since 2010, which provides a 100 keV deuterium neutral beam of 6.0 MW maximum using three ion sources.
The second NBI (NBI-2) also consist with three ion sources which arranged vertically with tangency radius of 1.56 m to provide balanced core heating and off-axis current drive will be constructed until 2019. An ion source will be commissioned 2018 KSTAR campaign, and the other two ion source will be applied to KSTAR from 2019. As the vacuum condition can substantially affect the beam performance, the vacuum pumping system for NBI-2 has been carefully designed. The cryopumps for NBI-2 were designed and the overall vacuum pumping system of NBI-2 was installed including turbo pumps, mechanical booster-pumps, and dry-pumps. In this paper, the detailed engineering design, fabrication, and installation results of large condensation cryopumps and vacuum sub-components were explained. The effective pumping speed and pressure distribution will be evaluated through the commissioning of the vacuum pumping system for NBI-2. Finally, we present the operation procedures of the NBI-2 vacuum pumping system.
•There has been progresses in the construction and 1st operation of DBU in 2016 KSTAR plasma experiments.•Two in-vessel cryopumps (CPIs) cool-down to 4.5K and observed pumping speed was ...3.0E4l/s.•Manual CPI regeneration tests were accomplished regarding future automatic control.•Production of the D2 pellets were successful and there has been lots of injection tests.
KSTAR project has required the new helium distribution box named upgraded distribution box (DBU) for the operation of the cryogenic components such as in-vessel cryo-pump (CPI), super-sonic molecular beam injector (SMBI), and deuterium pellet injection system (PIS). Two CPIs are inserted into the tokamak vacuum vessel and these components shall be operated at 90K for the liquid nitrogen thermal shields and 4.5K for the hydrogen cryo-panel. One hydrogen PIS was newly mounted on the tokamak for the 2016 KSTAR campaign. Liquid nitrogen shall be supplied to the one SMBI. For the operation of above mentioned 3 kinds of cryogenic components, a helium refrigerator, which had been used for the R&D in the KSTAR facility construction phase (2002–2013), was moved and inserted into the KSTAR 9kW helium facility room. The cooling capacity of the refrigerator at 4.5K is 1kW and it was manufactured from the Linde Kryotechnik before 2002. After some maintenances in warm compressor, electrical power supply, oil-filter, and so on, commissioning of the refrigerator up to 4.5K was accomplished successfully. From the beginning of 2015, design and fabrication of the DBU was started. It shall control the liquid nitrogen for the SMBI and CPI thermal shields whereas liquid helium for the CPI cryo-panel and PIS. To minimize the temperature of the liquid nitrogen to be supplied to SMBI and CPI, a thermal damper tank was inserted into the distribution box. Nitrogen return gases are to be warmed up to room temperature at the heater in the distribution box. A 1000l of liquid helium vessel is located nearby the PIS to supply cold gas helium (∼5K). Because the CPI cryo-panel requires regeneration up to 90K, complex regeneration and re-cool down scenario was developed and applied to the DBU. Including operational results, details of the DBU progresses will be reported in this paper.
A 154 kV class high-temperature superconducting (HTS) power cable system Is developing in Korea. For insulation design of this cable, the grading method of insulating paper is proposed. The ...electrical insulation material has been used two kind of laminated polypropylene paper (LPP) that has different thickness. The use of graded insulation gives improved mechanical bending properties of the cable. Also, within a HTS cable technology the terminations are important components. A HTS cable termination is energized with the line-to-ground voltage between the coaxial center and outer surrounding conductors, in the axial direction there is a temperature difference from ambient to about 77 K. For insulation design of this termination, the insulation material of the termination body used glass fiber reinforced plastic (GFRP) and the capacitance-graded method is proposed. Therefore, in order to insulating design of a 154 kV class HTS power cable and termination, this paper will report on the experimental investigations in impulse breakdown and surface flashover characteristics of the insulation materials. Based on these experimental data, the electrical insulation design of a 154 kV class HTS power cable and termination were calculated.
A research on several characteristics such as volume breakdown and surface discharge of insulators for a termination of power transmission class high temperature superconducting (HTS) cable was ...performed. In this paper, we investigated the surface discharge of glass fiber reinforced plastic (GFRP) in the air, nitrogen gas (GN 2 ) and cryogenic nitrogen gas (CGN 2 ) media. The breakdown characteristics of these media were also studied. Experimental results revealed that flashover voltage greatly depends on pressure, temperature, the kinds of insulating media and voltages. However, it is shallowly affected by shape and material of electrode. The breakdown voltage of liquid nitrogen (LN 2 ), GN 2 and CGN 2 deeply depends on the shape and dimension of electrode, kinds of voltages and pressure. Moreover, the breakdown voltage of CGN 2 and flashover voltage of GFRP in the CGN 2 is also influenced by temperature and vapor-mist density of the gas
Overview of nuclear data production system at RAON Ham, C.; Tshoo, K.; Lee, S. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
August 2023, 2023-08-00, Volume:
541
Journal Article
Peer reviewed
Nuclear Data Production System (NDPS), a fast neutron facility for nuclear science and applications, was constructed at the Rare Isotope Accelerator complex for ON-line experiments (RAON) in Korea. ...NDPS is designed to provide both white and quasi-monoenergetic neutrons using 98 MeV deuteron and 20 – 83 MeV proton beams with thick graphite and thin lithium targets, respectively. Neutron energy is determined by employing the Time-Of-Flight (TOF) technique, along with a pulsed deuteron (or proton) beam with a repetition rate of less than 200 kHz. Fast neutrons are produced in the target room and are guided to the TOF room through a 4 m long neutron collimator consisting of iron and 5% borated polyethylene. The neutron beam is monitored using a parallel plate avalanche counter (PPAC) and a micro-mesh gaseous (MICROMEGAS) detector installed in the TOF room, so as to measure the energy and the position of neutrons.