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In the context of KSTAR plasma research, the discovery of the fast ion regulated enhanced mode is noteworthy due to its remarkable ability to maintain ion temperatures exceeding up to 10 keV for a few tens of seconds, avoid impurity accumulation, and keep low loop voltages. This new plasma operating scenario is achieved in a diverted configuration plasma by avoiding the H-mode transitions with sufficient additional power for the transition. Keeping the density low is the primary method for the avoidance. Additionally, adjustments to other parameters (plasma shape, neutral beam injection, and toroidal magnetic field) associated with the H-mode threshold power are applied to inhibit the transition process. This paper includes an experimental analysis and discussion of these findings. [ABSTRACT FROM AUTHOR]

The recrystallization behavior of cold-rolled Al–Zn–Mg–Cu-based alloy sheets was systematically investigated by varying the Cu and Mg contents. With increasing Cu and Mg contents, the recrystallized grain size was reduced from 54.9 to 23.3 μ m owing to the reduced ratio of the size to volume fraction of microscale particles. Interestingly, the sensitivity of different particles to particle-stimulated nucleation (PSN), which is reflected by the linear experimental coefficient (k), was dependent on their morphologies and relative fractions. The k value was considerably small (0.07) in the Cu-free alloys, implying that the Zn and Mg containing particles have an insignificant effect on the PSN. However, the k value increased significantly to 0.61 with the increase in Cu content to 1.3 wt%, because the rod-shaped Al7Cu2Fe particles formed a large plastic deformation zone around them. The addition of 2.0 wt% Mg led to the increase in the relative fraction of round-shaped Al2CuMg particles, increasing the k value from 0.46 to 0.86. The Al7Cu2Fe particles were a stronger source of PSN than the Al2CuMg particles, forming more recrystallized grains. Although Mg addition could increase the yield strength of the aged sheets, a strength–ductility trade-off arose. However, the addition of Cu simultaneously increased the yield strength and elongation because the uniform distribution of grain boundary precipitates caused by grain refinement could reduce the stress concentration during plastic deformation. [ABSTRACT FROM AUTHOR]

Nuclear fusion is one of the most attractive alternatives to carbon-dependent energy sources1. Harnessing energy from nuclear fusion in a large reactor scale, however, still presents many scientific challenges despite the many years of research and steady advances in magnetic confinement approaches. State-of-the-art magnetic fusion devices cannot yet achieve a sustainable fusion performance, which requires a high temperature above 100 million kelvin and sufficient control of instabilities to ensure steady-state operation on the order of tens of seconds2,3. Here we report experiments at the Korea Superconducting Tokamak Advanced Research4 device producing a plasma fusion regime that satisfies most of the above requirements: thanks to abundant fast ions stabilizing the core plasma turbulence, we generate plasmas at a temperature of 100 million kelvin lasting up to 20 seconds without plasma edge instabilities or impurity accumulation. A low plasma density combined with a moderate input power for operation is key to establishing this regime by preserving a high fraction of fast ions. This regime is rarely subject to disruption and can be sustained reliably even without a sophisticated control, and thus represents a promising path towards commercial fusion reactors.A magnetic confinement regime established at the Korea Superconducting Tokamak Advanced Research device enables the generation of plasmas over 108 kelvin for 20 seconds with the aid of fast ions without plasma edge instabilities or impurity accumulation. [ABSTRACT FROM AUTHOR]

Korea Superconducting Tokamak Advanced Research (KSTAR) program has made significant advances in the development of long pulse and high-performance plasma scenarios, utilizing the advantages of the fully superconducting tokamak. Ten years of KSTAR operation have produced outstanding progress in plasma control, extending the operating window of the plasma discharges, and achieving the H-mode up to 1.2 MA in plasma current, up to 90 s at top duration, and up to 2.16 in elongation. The unique features of the KSTAR device also produced a record 30 s long pulse in H-mode operation without an edge-localized-mode (ELM) crash, and progress in the fundamental transport physics through systematic study, using unique diagnostic capabilities. Therefore, the next near-term research focus will be on how to extend the high performance plasmas up to 300 s by overcoming scientific and engineering obstacles to steady state operation. For fusion reactors, the tokamak device needs to sustain a permanent plasma current. It is also known that the bootstrap current should play an important role in the plasma current for an efficient fusion reactor, and its contribution should be over as high as possible. An internal transport barrier discharge based on the reverse shear profile of the safety factor is one of the promising candidates for enhancing the bootstrap current. However, even in reverse shear mode, an additional external off axis current drive (CD) should be provided to control the current profile, as well as to supplement the plasma current. KSTAR has pursued steady state to operation, aiming for a fully non inductive state, based on real time (RT) plasma control by maximizing the long pulse capabilities of the superconducting machine. In order to deposit current at an arbitrary position, the first requirement is to have many highly efficient CD actuators capable of profile diversity. KSTAR has prepared several RF CD portfolios in addition to a conventional on and off axis CD neutral beam injection (NBI) system. The final target of an off axis current drive will be a 4 MW off-axis NB, 8 MW on-axis NB, 6 MW electron cyclotron heating (ECH), and 4 MW radio frequency heating and current drive (RFHCD) (ion cyclotron (IC), lower hybrid (LH), Helicon CD). In addition, as a long-term goal, demonstrating a long pulse core edge compatible plasma in a reactor relevant condition is important in present medium size tokamak, since it is expected to sustain a very high pressure pedestal height plasma using super H-mode, with parallel upgrades of the superconducting toroidal field (TF) coils. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Computerized Dentistry is the property of Quintessence Publishing Company Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The applications of hydrated layered polysilicates, particularly magadiite, have rapidly expanded from selective cation adsorption to fabrication of nanomaterials even without full understanding of their adsorption reactions. This study has successfully elucidated the distinguished adsorption behavior of magadiite, spontaneous nanoparticle formation coupled with selective adsorption reactions. Magadiite exhibited highly reliable and selective adsorption, especially for Cu2+ and Pb2+. The adsorbed heavy metal cations besides Cu2+ and Pb2+ were spontaneously and systematically transformed into the corresponding hydroxide nanoparticles exclusively on the crystal edges and the nanoparticles ultimately sprouted out of the crystals on full growth. Cation selectivity is explained by the compatibility of the interlayer silanol configuration with coordination of the adsorbed cations whereas spontaneous nanoparticle formation by the changes of the silanol configuration through the grafting reaction of the adsorbed cations is due to the high flexibility of the silicate frameworks. These unique adsorption behaviours of hydrated layered polysilicates, particularly magadiite, provide a new strategy not only for developing advanced purification/retrieval technologies but also for tailor-making various nanoparticles. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Computerized Dentistry is the property of Quintessence Publishing Company Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background The secondary cell wall is a defining feature of xylem cells and allows them to resist both gravitational forces and the tension forces associated with the transpirational pull on their internal columns of water. Secondary walls also constitute the majority of plant biomass. Formation of secondary walls requires co-ordinated transcriptional regulation of the genes involved in the biosynthesis of cellulose, hemicellulose and lignin. This co-ordinated control appears to involve a multifaceted and multilayered transcriptional regulatory programme. Scope Transcription factor MYB46 (At5g12870) has been shown to function as a master regulator in secondary wall formation in Arabidopsis thaliana. Recent studies show that MYB46 not only regulates the transcription factors but also the biosynthesis genes for all of the three major components (i.e. cellulose, hemicellulose and lignin) of secondary walls. This review considers our current understanding of the MYB46-mediated transcriptional regulatory network, including upstream regulators, downstream targets and negative regulators of MYB46. Conclusions and Outlook MYB46 is a unique transcription factor in that it directly regulates the biosynthesis genes for all of the three major components of the secondary wall as well as the transcription factors in the biosynthesis pathway. As such, MYB46 may offer a useful means for pathway-specific manipulation of secondary wall biosynthesis. However, realization of this potential requires additional information on the ‘MYB46-mediated transcriptional regulatory programme’, such as downstream direct targets, upstream regulators and interacting partners of MYB46. [ABSTRACT FROM PUBLISHER]

The high fraction of runaway current conversion following disruptions has an important effect on the first wall for next-generation tokamaks. Because of the potentially severe consequences of a large full current runaway beam on the first wall in an unmitigated disruption, runaway suppression is given a high priority. The behavior of runaway currents both in spontaneous disruptions and in D2 massive gas injection (MGI) shutdown experiments is investigated in the KSTAR tokamak. The experiments in KSTAR show that the toroidal magnetic field threshold, BT > 2 T, for runaway generation is not absolute. A high fraction of runaway current conversion following spontaneous disruptions is observed at a much lower toroidal magnetic field of BT = 1.3 T. A dedicated fast valve for high-pressure gas injection with 39.7 bar is developed for the study of disruptions. A study of runaway current parameters shows that the conversion efficiency of pre-disruptive plasma currents into runaway current can reach over 80% both in spontaneous disruptions and in D2 MGI shutdown experiments in KSTAR. [ABSTRACT FROM AUTHOR]

This study presents a complete algorithm for single target tracking in clutter, which addresses simultaneously: nonlinear measurements; uncertain target detections; presence of random clutter measurements; and uncertain target existence. Proposed algorithm generalises the integrated track splitting (ITS) filter by extending the ITS functionality to highly nonlinear measurements. The non-linear target tracking and estimation problems may also be solved by application of particle filters, albeit incurring a significant computational expense relative to proposed solution. In an environment without data association uncertainties proposed filter becomes a non-linear estimator. [ABSTRACT FROM AUTHOR]

The aqueous corrosion behavior of low-alloy steel with aluminum contents was examined in a 10 wt% H2SO4 (pH 0.13) solution using electrochemical techniques and surface analyses. The corrosion resistance of the new alloy steel was evaluated in terms of electrochemical parameters, such as passive current density, film, and charge transfer resistances. The results showed that a high Al content in the steel imparted better passivation behavior resulting in a lower corrosion rate. It related to the enrichment of iron carbonate and hydrocarbon by the dissolution of the carbide phase. [ABSTRACT FROM AUTHOR]

The latest results of confinement and edge-localized mode (ELM) characteristics ofKorea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasmas are reported. The estimation of fast ion contribution to the total stored energy, calculated by both the NUBEAM and ASTRA simulations, and of the effective total heating power is used to derive the thermal energy confinement time (τE,thermal), which is compared with a multi-machine database. The measured power threshold for the L-H transition (Pthr) as a function of density shows a roll-over with minimum value at ñe ~ 2 × 1019 m-3. KSTAR H-mode plasmas exhibit three distinctive types of ELMs: large type-I ELMs, intermediate ELMs and a mixed (type-I and small ELM peaks) ELM regime. Power scans show that the frequency of the large ELMs increases with increasing heating power, a feature of type-I ELMs. The quality of confinement is higher for type-I and mixed ELMy H-mode (H98(y,2) ~ 0.9-1) than for the intermediate ELM regime (H98(y,2) ~ 0.7). Type-I ELMs have precursor-like signals from the magnetics measurement, while the other two ELM types do not. The low-field side (LFS) profile of electron temperature (Te), from the ECE measurement, and the pedestal profile of the toroidal velocity (Vt), from charge-exchange spectroscopy, show a continuous build up on the LFS during the inter-ELM period. However, the pedestal ion temperature (Ti) remains unchanged for most of the inter-ELM period until it rapidly rises in the last stage of the ELM cycle (≥70-80%). The estimated electron pedestal collisionality for a type-I ELMy regime is e*~0.5-0.6. The confinement and ELM characteristics for the ELM suppression discharges by the application of an n = 1 magnetic perturbation (MP) have also been investigated for each of the identified stages during the MP application. A second L-H transition during the L-mode phase after the end of first H-mode stage occurs for some discharges when the divertor configuration is restored by the plasma control system. Characteristics of this late H-mode are compared with those for the main H-mode. [ABSTRACT FROM AUTHOR]

Purpose: To compare helical tomotherapy (HT) and conventional intensity-modulated radiotherapy (IMRT) using a variety of dosimetric and radiobiologic indexes in patients with locally advanced non-small cell lung cancer (LA-NSCLC).Patients and Methods: A total of 20 patients with LA-NSCLC were enrolled. IMRT plans with 4-6 coplanar beams and HT plans were generated for each patient. Dose distributions and dosimetric indexes for the tumors and critical structures were computed for both plans and compared.Results: Both modalities created highly conformal plans. They did not differ in the volumes of lung exposed to > 20 Gy of radiation. The average mean lung dose, volume receiving ≥ 30 Gy, and volume receiving ≥ 10 Gy in HT planning were 18.3 Gy, 18.5%, and 57.1%, respectively, compared to 19.4 Gy, 25.4%, and 48.9%, respectively, with IMRT (p = 0.004, p < 0.001, and p < 0.001). The differences between HT and IMRT in lung volume receiving ≥ 10-20 Gy increased significantly as the planning target volume (PTV) increased. For 6 patients who had PTV greater than 700 cm(3), IMRT was superior to HT for 5 patients in terms of lung volume receiving ≥ 5-20 Gy. The integral dose to the entire thorax in HT plans was significantly higher than in IMRT plans.Conclusion: HT gave significantly better control of mean lung dose and volume receiving ≥ 30-40 Gy, whereas IMRT provided better control of the lung volume receiving ≥ 5-15 Gy and the integral dose to entire thorax. In most patients with PTV greater than 700 cm(3), IMRT was superior to HT in terms of lung volume receiving ≥ 5-20 Gy. It is therefore advised that caution should be exercised when planning LA-NSCLC using HT. [ABSTRACT FROM AUTHOR]

In- and outboard plasma facing components (PFCs) of Korea Superconducting Tokamak Advanced Research (KSTAR) have been fully installed in 2010 for D-shaped diverted plasmas. Before the start of plasma operation, the PFCs were baked up to 200 ^\circ\C by hot nitrogen gas circulation system to remove impurities including water. The surface temperature of the PFC tiles was monitored by 200 thermocouple sensors during the plasma operation [plasma shot or glow discharge cleaning (GDC)], and the temporal and spatial (poloidal) temperature profiles are obtained. Depending on the heat flux on each tile, the surface temperature shows time-dependent behavior. After 1-h morning He GDC, the temperature of the PFCs at the inboard side has reached to 40 ^\circ\C. After an H-mode shot, the temperature of divertor tiles around the striking points was substantially increased. The time-averaged total heat flux after a few of L- and H-modes in 2010 was estimated to be approximately 0.010 \MW/m^2. [ABSTRACT FROM PUBLISHER]

To evaluate the effects of plasma total homocysteine (tHcyt) and the MTHFR 677C>T polymorphism on determining the intracranial- (IC) and extracranial (EC) locations of atherosclerosis. Brain MR angiography was performed on 463 patients with symptomatic ischaemic stroke to detect significant atherosclerosis (more than 50% stenosis of vessel diameter) in the IC- and EC arteries. Relationships between IC- or EC atherosclerosis and plasma tHcyt level and/or MTHFR 677C>T genotypes were analyzed after adjusting for vascular risk factors. The odd ratios (ORs) of plasma tHcyt were not significantly higher in patients with either IC- or EC atherosclerosis than in patients with no atherosclerosis. When the study subjects were stratified into three subgroups according to their plasma tHcyt levels, neither the crude ORs nor adjusted ORs of each IC- and EC atherosclerosis in highest and middle plasma tHcyt tertile were significantly different from those in lowest plasma tHcyt tertile. The ORs of the MTHFR 677TT genotype in IC- and EC atherosclerosis were not significantly different from those in no atherosclerosis. There was no dose-dependent effect of MTHFR 677T allele on either IC- or EC atherosclerosis. Plasma tHcyt level and the MTHFR 677C>T polymorphism do not contribute to the distribution of cervico-cerebral atherosclerosis in ischaemic stroke patients. [ABSTRACT FROM AUTHOR]

The Mononobe-Okabe method is widely used in practice to estimate dynamic active earth pressure. The method, derived from Coulomb's theory, cannot account for the effect of cohesion and hence cannot be used for a cohesive backfill. In addition, the effect of wall adhesion and external load cannot be taken into account. This paper develops a new general formula for dynamic active earth pressure on a yielding wall. The strength of the formula is that it can take into account the effects of cohesion, wall adhesion and external load on dynamic active pressure, while remaining simple in form. The dynamic earth pressures calculated by the proposed formula, the Mononobe-Okabe method, and the graphical solution are compared for validation. The comparisons demonstrate the accuracy of the proposed formula. The formula is used in a parametric study to investigate the influence of cohesion, wall adhesion and external load. This study shows that the additional terms can significantly influence the calculated dynamic active earth pressure. [ABSTRACT FROM AUTHOR]

KSTAR (Korea Superconducting Tokamak Advanced Research) superconducting magnet consists of a CICC (Cable-In-Conduit Conductor) and is cooled down less than 5 K using supercritical helium. The length of CICC is 610 m for TF coil and maximum about 2,500 m for PF coil respectively, especially the cooling channel is about maximum 300 m in PF coil because of continuous winding scheme. There are many cooling channels in KSTAR coils especially 84 channels in TF magnet system and 100 channels in PF magnet system. Flow imbalance affects cool down of magnet and leads to a difficulty of flow control. The pressure drop between CICC terminals has a close relationship with CICC hydraulic characteristic, helium refrigerator's performance and efficiency. The friction factor which is a representative parameter can be obtained under cryogenic operation condition. We attempt to find out the friction factor of KSTAR CS and PF CICC according to the test result of KSTAR CSMC (Central Solenoid Model Coil) 2nd campaign and compare the results with previous tests. The hydraulic characteristics of KSTAR superconducting magnet system like mass flow distribution, friction factor in conductor, pressure drop and etc during CSMC test and initial commissioning of KSTAR are presented. We can confirm the KSTAR CICC's unique hydraulic behavior in states of cool down and current charging period. Also, we expect that measured data will help to operate KSTAR and be a reference for thermo-hydraulic simulation. [ABSTRACT FROM AUTHOR]

The KSTAR components requiring cryogenic helium coolant for superconducting magnet operations are connected to the helium refrigeration system (HRS) through the helium distribution system (HDS), the final helium distribution station. Twenty eight cryogenic valves including 4 quench protecting valves, many sensors such as temperature sensors, pressure transmitters, and flowmeters are mounted on the system. The HDS has to control the 4.5 K supercritical helium (600 g/s) for 30 superconducting coils and their superconducting bus-lines, 55 K helium (270 g/s) pressurized to 18 bars for the thermal shields and the gravity supports, and a maximum 17.5 g/s of liquid helium for 18 current leads, provided from the HRS which has a 4.5 K equivalent cooling power of 9kW. The helium distribution system consists of a helium distribution box (DB), 5 helium transfer lines, a PLC based helium control system (HCS), etc. The helium control system is connected to the KSTAR supervisory control & interlock system. The detailed status regarding the construction, commissioning during first cool-down, and the instrumentation & control (I&C) system are included in this paper. [ABSTRACT FROM AUTHOR]

The magnet system comprises sixteen toroidal field (TF) coils and fourteen poloidal field (PF) coils for KSTAR (Korea Superconducting Tokamak Advanced Research) Tokamak. All the TF coils and 10 PF coils (PF1~ 5 UL) are made of Nb3 Sn strands and 4 PF coils (PF6 ~ 7 UL) are made of NbTi strands. Before operating the superconducting coils, it is critical to verify the operation conditions such as thermo-hydraulic parameters and stability boundaries. In this regards, the TF model coil and CSMC (Central Solenoid Model Coil) have been tested and the operating conditions have been analyzed. Before cool down, parameters such as helium flow through conduits, electrical insulation and coil geometry have been measured at room temperature to confirm the manufacturing soundness. During cool down and current charging, thermo-hydraulic and mechanical parameters by using mechanical sensors have been measured. Also measured was the magnetic field strength in various positions of the coil conductor. Measured data have been analyzed and the results have been compared with the model analysis by simulation code. [ABSTRACT FROM AUTHOR]

A series of batch experiments on free swell, hydraulic conductivity, and contaminant removal efficiency was performed for the combination of bentonite and zero valent iron (ZVI), in order to identify the optimal mixing ratio between bentonite and ZVI. The swell volume of the bentonite-ZVI mixtures did not change with increasing ZVI, and the hydraulic conductivity decreased as the ZVI increased. The reduction rates and removal efficiencies of trichloroethylene (TCE), Chromium(VI), and nitrate increased as ZVI content increased, while there was no practical difference in removal efficiencies between 30% and 100% of ZVI weight contents. Therefore, 30% of the ZVI content was used as the optimal amount in this research since the physical properties, such as swell volume and hydraulic conductivity, as well as the contaminant sorption and reduction were the most efficient. From Raman spectrophotometer analysis, peaks of magnetite, maghemite, and hematite were observed on the surfaces of the bentonites that had been used for the mixtures. Since iron oxides are strong adsorbers of contaminants and magnetites can facilitate the electron transfer of irons, these formations are beneficial for the long-term performance of the iron metals. [ABSTRACT FROM AUTHOR]

The Korea Superconducting Tokamak Advanced Research (KSTAR) device requires R&D of 20-30 kA overloaded current leads (OCL) for the superconducting poloidal field (PF) magnet. The PF magnet is under zero current state for a very long time, as it is often the case for superconducting magnets used in nuclear fusion. In such case, a simple approach to reduce the cryogenic load would be to design the current leads to be overloaded. Two main problems in this R&D area are the reduction of the cryogenic heat load and the temperature rise due to the current overloading. In this paper, the current overloading tests and results of the numerical analysis for brass leads are presented and discussed in detail. [ABSTRACT FROM AUTHOR]

Background: Although stent assisted angioplasty is an effective treatment for coronary and peripheral arterial disease, its efficacy in intracranial arteriosclerotic disease has not been verified.Objectives: To assess the radiographic and clinical outcome of stent assisted angioplasty for symptomatic middle cerebral artery (MCA) stenosis.Methods: We attempted stent assisted angioplasty in 14 patients with symptomatic high grade stenosis (>60%) on the proximal portion of the MCA, who had experienced either recurrent transient ischaemic attacks (TIAs) resistant to medical therapy or one or more stroke attacks. Patient records were analysed for angiographic characteristics, degree of stenosis, pre-procedural regimen of anti-platelet and/or anti-coagulation agents, use of devices, procedure related complications, pre-operative and post-operative single photon emission computed tomography (SPECT) findings, and clinical and radiographic outcomes.Results: Stent assisted angioplasty was successfully performed in 8 of 14 patients without any serious complications and unsuccessful in 2 of 14 patients due to the tortuous curve of the internal carotid artery siphon. Four patients had complications. Two patients had an arterial rupture; one patient was rescued by an additional stent and balloon tamponade, the other patient died. Complications in the other two patients included thrombotic occlusion and distal thrombosis. Residual stenosis was less than 50% in diameter in all the patients. All eight patients who underwent follow up cerebral angiography had no restenosis. Follow up SPECT showed improved perfusion in the affected MCA territory in all the tested patients with TIA and in one of three stroke patients. Using the modified Rankin Scale at follow up, four of five TIA patients and five of six stroke patients were assessed as functionally improved or having a stable clinical status.Conclusion: Although the re-stenosis rate in stent assisted angioplasty seems to be better than in primary balloon angioplasty as reported previously, the complication rate is still high. Elective stenting is an alternative therapeutic method for the prevention of secondary ischaemic stroke in stroke patients with MCA stenosis, and seems to be a potentially effective but also hazardous therapeutic technique in patients with recurrent TIAs. This study indicates the need for randomised control trial data of this intervention. Additionally, long term follow up data and additional clinical experience are required to assess the durability of this procedure. [ABSTRACT FROM AUTHOR]

The Korea superconducting tokamak advanced research (KSTAR), which is under construction at the National Fusion R&D Center, Korea Basic Science Institute, Daejeon, Korea, has the mission to develop a steady-state capable advanced superconducting tokamak to establish the scientific and technological bases for a fusion reactor. After an intensive R&D program, substantial progress of the KSTAR tokamak engineering had been made on major tokamak structures, superconducting magnets, in-vessel components, diagnostic system, heating system, and power supplies with industrial manufacturers by May 2002. The engineering design has been elaborated to the extent necessary to allow a realistic assessment of its feasibility, performance, and cost. Since May 2003, the project has been in the phase of procurement. The fabrication of main tokamak structure such as vacuum vessel, cryostat, and supporting structures is well progressed. The manufacturing work of superconducting coils is also proceeding favorably. The tokaniak assembly started in July 2003 after site preparation and assembly jig. The start of commissioning is scheduled for June 2006. This paper describes the key features and engineering progress of the KSTAR tokamak and elaborates the work currently underway. [ABSTRACT FROM AUTHOR]

A Thomson scattering system on the Hanbit magnetic mirror device has been installed to measure the electron temperature and density of the plasma in the central cell. The configuration is based on a standard 90° scattering scheme. The optical system consists of a Q-switched Nd:YAG laser, input optics, collection optics, spectrograph optics, detectors, and a data acquisition system. Although the laser beam path is about 50 m long and the background emissions are not low, the electron temperature measurements have been made at a single point on a shot-by-shot basis, in which the stray light was considerably suppressed by using a beam dump, a viewing dump, and baffles. The measured electron temperature is about 50–70 eV in experiments for plasma production and heating by ICRF of 200-kW-rf power using a slot antenna. A description of the installed system and the experimental results are presented. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Many frustrating experiences have been encountered when the training of neural networks by local search methods becomes stagnant at local optima. This calls for the development of more satisfactory search methods such as evolutionary search. However, training by evolutionary search can require a long computation time. In certain situations, using Lamarckian evolution, local search and evolutionary search can complement each other to yield a better training algorithm. This paper demonstrates the potential of this evolutionary-learning synergy by applying it to train recurrent neural networks in an attempt to resolve a long-term dependency problem and the inverted pendulum problem. This work also aims at investigating the interaction between local search and evolutionary search when they are combined. It is found that the combinations are particularly efficient when the local search is simple. In the case where no teacher signal is available for the local search to learn the desired task directly, the paper proposes introducing a related local task for the local search to learn, and finds that this approach is able to reduce the training time considerably. [ABSTRACT FROM AUTHOR]

Electronic structures of spinel oxides FeT2O4 (T = V, Cr) have been investigated by employing soft x-ray magnetic circular dichroism (XMCD) and soft x-ray absorption spectroscopy (XAS). XAS reveals that Cr and V ions are trivalent, and that Fe ions are nearly divalent in FeT2O4 (T = V, Cr). Finite XMCD signals are observed in FeV2O4 at T = 80 K, while they are very weak in FeCr2O4. XMCD shows that Fe spins are antiparallel to V and Cr spins, with the V and Cr spins being canted from Fe spins, which suggests a Yafet-Kittel type triangular spin configuration in FeT2O4 (T = V, Cr). [ABSTRACT FROM AUTHOR]

A piezoelectric valve, which has a flow rate of about 463 mbar l/s, has been installed to fuel the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. The valve flow rate is in situ calibrated by analyzing the pressure rise curve while fueling the vessel at a constant rate. The calibration method and results are presented. In addition to the flow rate, other vacuum system parameters, such as the pumping speed and the vessel volume, were experimentally obtained. Based on these measurements, a KSTAR vacuum system simulator was developed to calculate the valve drive signal to obtain a programmed pressure trace. An arbitrarily shaped pressure trace was successfully controlled in KSTAR with this hardware and software system. [ABSTRACT FROM AUTHOR]

Sildenafil citrate (Viagra®) is one of the frequently prescribed drugs for men with erectile dysfunction. We describe a 52-year-old man with bilateral middle cerebral artery (MCA) territory infarction after sildenafil use. He ingested 100 mg of sildenafil and about 1 h later, he complained of chest discomfort, palpitation and dizziness followed by mental obtundation, global aphasia and left hemiparesis. Brain magnetic resonance imaging documented acute bilateral hemispheric infarction, and cerebral angiography showed occluded bilateral MCA. Despite significant bilateral MCA stenosis and cerebral infarction, systemic hypotension persisted for a day. We presume that cerebral infarction was caused by cardioembolism with sildenafil use. [ABSTRACT FROM AUTHOR]

A simple-but-efficient calibration-spur reduction technique is introduced that utilises the digital-and-analogue hybrid return-to-zero (HRZ) method in a current-steering DAC employing a roundrobin- fashioned background current-source calibration scheme. A simulation with a 12 b 500 MS/s current-steering DAC showed 9.9 and 7.8 dB improvements in the spur-free dynamic range and signalto-noise + distortion ratio, respectively, owing to the reduced calibration spur by the proposed HRZ technique. [ABSTRACT FROM AUTHOR]

A simple‐but‐efficient calibration‐spur reduction technique is introduced that utilises the digital‐and‐analogue hybrid return‐to‐zero (HRZ) method in a current‐steering DAC employing a round‐robin‐fashioned background current‐source calibration scheme. A simulation with a 12 b 500 MS/s current‐steering DAC showed 9.9 and 7.8 dB improvements in the spur‐free dynamic range and signal‐to‐noise + distortion ratio, respectively, owing to the reduced calibration spur by the proposed HRZ technique. [ABSTRACT FROM AUTHOR]

The article presents a case study of an old woman with multiple myeloma with hemorrhagic bullous colitis. The computed tomography (CT) scan of the patient shows diffuse edematous wall thickening across the rectum and colon. It notes the visibility of some high density lesions in the lumen. It concludes that the patient suffers from ischemic colitis.

A letter to the editor is presented in response to the case study of a woman with multiple myeloma treated through autologous blood stem cell transplantation.

A fast ion loss detector (FILD) has been installed and tested in Korea Superconducting Tokamak Advanced Research (KSTAR). KSTAR FILD measures the energy and the pitch-angle of the escaping ions with the striking positions on the scintillator plane. Measurements of the fast ion loss have been performed for the neutral beam heated plasmas. Initial experimental results indicate the prompt losses from neutral beam are dominant and the effects of the resonant magnetic perturbation on the fast ion loss are investigated. In addition, further design change of the detector-head in order to avoid excessive heat load and to detect the fusion products or the fast ions having order of MeV of energy is also discussed. [ABSTRACT FROM AUTHOR]