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During the Large Helical Device (LHD) experiments, many scientists and technical staff are working in the central control room to operate the experiment. They must manage the diagnostics and controlling devices referring to the results of the last plasma shot. Also, the experiment coordinator must decide the conditions for the subsequent experiments using the results. Furthermore, many scientists are participating in the experiment from remote sites. Therefore, it is important to share the information in the control room quickly, such as the results of the last plasma discharge, with the remote user as well as with the staff in the room. In this paper, the data monitoring environment in the LHD central control room is introduced.

Upon beginning the LHD deuterium experiment, the opportunity for maintenance work in the torus hall will be conspicuously reduced such that all instruments must be controlled remotely. The LHD data acquisition (DAQ) and archiving system have been using about 110 DAQ front-end, and the DAQ central control and monitor system has been implemented for their remote management. This system is based on the “multi-agent” model whose communication protocol has been unified. Since DAQ front-end electronics would suffer from the “single-event effect” (SEE) of D-D neutrons, software-based remote operation might become ineffective, and then securely intercepting or recycling the electrical power of the device would be indispensable for recovering from a non-responding fault condition. In this study, a centralized control and monitor system has been developed for a number of power distribution units (PDUs). This system adopts the plug-in structure in which the plug-in modules can absorb the differences among the commercial products of numerous vendors. The combination of the above-mentioned functionalities has led to realizing the flexible and highly reliable remote control infrastructure for the plasma diagnostics and the device management in LHD.

The LHD data acquisition and archiving system, i.e., LABCOM system, has been fully equipped with high-speed real-time acquisition, streaming, and storage capabilities. To deal with more than 100 MB/s continuously generated data at each data acquisition (DAQ) node, DAQ tasks have been implemented as multitasking and multithreaded ones in which the shared memory plays the most important role for inter-process fast and massive data handling. By introducing a 10-second time chunk named “subshot,” endless data streams can be stored into a consecutive series of fixed length data blocks so that they will soon become readable by other processes even while the write process is continuing. Real-time device and environmental monitoring are also implemented in the same way with further sparse resampling. The central data storage has been separated into two layers to be capable of receiving multiple 100 MB/s inflows in parallel. For the frontend layer, high-speed SSD arrays are used as the GlusterFS distributed filesystem which can provide max. 2 GB/s throughput. Those design optimizations would be informative for implementing the next-generation data archiving system in big physics, such as ITER.

The large helical device (LHD), which is the world largest helical confinement system, is a national project serving Japanese fusion community. In LHD, experiments of 7000 shots are carried out for 250 proposals every year. Efficient experiment arrangement is required in order to carry out many collaborators’ proposal. Sometimes collaborators who are not familiar to LHD stay at NIFS only a few day to join the experiment. Issues are as follows: how to reduce collaborator's effort, how to reduce manager's effort to optimize the schedule; how to publicize plan and results of the experiment. We have developed web systems of virtual printer, experimental proposal and scheduling by using Ruby on Rails (RoR), which encapsulates relational data base (RDB) and AJAX. RDB enables to make tables by searching and sorting data with key words. Web servers are equipped in the virtual computer system in order to minimize efforts and cost of maintenance. The LHD web portal has been also developed in order to provide collaborators an efficient and intuitive interface to access the above systems, to take LHD information, and to use tools for LHD data analysis. The web systems have reduced collaborators’ and managers’ efforts significantly.

This paper presents the control, data acquisition, data analysis and remote participation facilities of the Large Helical Device (LHD), which is designed to confine the plasma in steady state. In LHD the plasma duration exceeds 3000 s by controlling the plasma position, the density and the ICRF heating. The “LABCOM” data acquisition system takes both the short-pulse and the steady-state data. A two-layer Mass Storage System with RAIDs and Blu-ray Disk jukeboxes in a storage area network has been developed to increase capacity of storage. The steady-state data can be monitored with a Web browser in real time. A high-level data analysis system with Web interfaces is being developed in order to provide easier usage of LHD data and large FORTRAN codes in a supercomputer. A virtual laboratory system for the Japanese fusion community has been developed with Multi-protocol Label Switching Virtual Private Network Technology. Collaborators at remote sites can join the LHD experiment or use the NIFS supercomputer system as if they were working in the LHD control room.

Control, data acquisition, plasma monitoring and remote participation for steady state operation in the large helical device (LHD) are reviewed. By controlling the impedance matching of ICH, the plasma position and the electron density, high temperature plasma is confined for 1905s. The plasma parameters are monitored in real time. Data are continuously sampled by the YOKOGAWA WE7000 system and by the NATIONAL INSTRUMENTS CompactPCI system. Those data are managed by the object-oriented database system based on ObjectStore in distributed servers with mass storage. By using the multi protocol label switching-virtual private network (MPLS-VPN) technology, the local area network of LHD is expanded to the Japanese fusion community. This provides the remote participants with the same environment of the LHD control room.

The effect of daily use of three different dentifrices on glucose retention after glucose mouth rinsing was tested in this study regarding xylitol and fluoride. Six experimental groups used three different dentifrices produced by two different companies: xylitol- and fluoride-containing dentifrice (XF), non-xylitol- and fluoride-containing dentifrice (F), and non-xylitol- and non-fluoride-containing dentifrice (NonX-NonF). Subjects were divided at random and rinsed their mouths for 15s with 20ml of 0.5M glucose solution. Glucose and lactate retention were determined by collecting samples of saliva from the approximal areas of the maxillary and mandibular anterior teeth and using the enzyme membrane test. Samples were collected 0, 1 and 2 months after the start of regular dentifrice use. There were significant differences in glucose retention in relation to the dentifrice used, month of sampling, site of sampling, and time since start of rinsing. Their contribution ratios were 2.0, 4.4, 11.7 and 7.4%, respectively (P0.01). There were significant differences observed between the XF and NonX-NonF groups, with the XF group presenting lower glucose retention than the NonX-NonF group. The XF group presented lower glucose retention than the F group. The F group showed lower glucose retention than the NonX-NonF group. There were significant differences in lactate retention in relation to the month and site of sampling, and their contribution ratios were 3.3 and 2.8%, respectively (P0.01). There were, however, no significant differences in glucose and lactate retention in relation to the dentifrice manufacturer. It was concluded that the XF dentifrice was the most effective, and the F dentifrice was more effective in reducing glucose retention than the NonX-NonF dentifrice.

Large-scale experiments such as ITER require international collaboration, and remote participation plays an important role in carrying out such experiments. Web-based applications are useful tools for scientists participating in experiments remotely using personal computers. Since the participants typically download web-based applications to their computer each time they access the web servers, they do not need to install extra software in order to use these applications. In addition, the application developers do not need to distribute the latest program files each time they are modified, thus reducing maintenance costs for remote participation systems. For these reasons, we have been developing web-based applications for the LHD experiments at NIFS. In a previous study, we showed the benefits of using Ruby on Rails (RoR) to develop web-based applications for analysis code. We thought this approach would also be useful for developing applications for remote participation. Therefore, we have developed several web-based applications using RoR for participating in the LHD experiments. These applications include a data viewer and a scheduler of experiments. The main reason to adopt RoR for this purpose is its efficiency for developing web-based applications. For example, to develop a data viewer, we used an existing program running on an X-Windows System. Using RoR, we could minimize the modifications of the existing programs to add web interfaces. In this paper, we will report a web-based application developed using RoR for the LHD experiment. We will also discuss the benefits of using RoR in developing remote participation tools.

Pump modulation is used to explore multimode interactions in an standing-wave Nd:YAG laser. Large amplitude modulation drives the system into apparent period doubling cascades and chaos as are expected for the nonlinear oscillations of the driven relaxation oscillations of the laser. However, examination of the intensity fluctuations and intensity power spectra of individual modes indicates that anti-phased fluctuations and subharmonic resonances are quite common and that they masquerade as simpler period-doubling phenomena. Even the sinusoidal response of a multimode laser to weak modulation is found to reveal multimode couplings in the distortions of the resonant frequency and width of the resonance as the pump current is raised, bringing more modes into the dynamics and strengthening the side modes.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A high-performance data acquisition (DAQ) system has been developed for steady-state fusion experiments at the Large Helical Device (LHD). Its significant characteristics are 110 MB s−1 continuous DAQ capability and the performance scalability using an unlimited number of DAQ units. Incoming data streams are first transferred temporarily onto the shared random access memory, and then cut into definite time chunks to be stored. They are also thinned out to 1/N to be served for the real-time monitoring clients. In LHD steady-state experiment, the DAQ cluster has established the world record for acquiring 90 GB/shot. The established technology of this steady-state acquisition and store can contribute to the ITER experiments whose data amount is estimated in the range 100 or 1000 GB/shot. This system also acquires experimental data from multiple remote sites through the fusion-dedicated virtual private network in Japan. The speed lowering problem in long-distance TCP/IP data transfer has been improved by the packet pacing optimization. The demonstrated collaboration scheme will be analogous to that of ITER and the supporting machines.

The difference in functional SH groups between two isozymes (alpha(+) and alpha forms) of (Na+ + K+)-ATPase was examined using omeprazole, a hydrophobic drug which was reported to modify SH groups of gastric (H+ + K+)-ATPase. Omeprazole inhibited rat brain and kidney (Na+ + K+)-ATPase activities in a time- and dose-dependent manner, and it inhibited incorporation of [3H]NEM into the catalytic subunit of the enzymes. The inhibition was greater in the brain enzyme than in the kidney enzyme. The inhibition of the brain enzyme showed a lag time, whereas the kidney enzyme was inhibited according to pseudo-first order kinetics. The inhibition by omeprazole of Na+-dependent phosphorylation and K+-stimulated phosphatase activity in the brain enzyme preparation was parallel with that of the overall (Na+ + K+)-ATPase reaction, while the partial reactions of the kidney enzyme showed different sensitivities to inhibition by omeprazole. Furthermore, the inhibition by omeprazole of [3H]NEM reactivity in the brain alpha(+) form was greater in the presence of SDS than in the absence, whereas the inhibition in the brain and kidney alpha forms was less in the presence of SDS than in the absence. These findings suggest that the isozymes of (Na+ + K+)-ATPase differ in hydrophobicity of SH groups of their catalytic subunits.

Administration of a diet containing 0.2% N-ethyl-N-hydroxyethylnitrosamine (EHEN) for 2 weeks induced hepatocellular carcinoma in 3 and renal tubular cell tumors in 7 of 9 Wistar rats. Diet containing 0.1% EHEN induced renal tubular cell tumors in 6 of 10 rats, but no hepatocellular carcinomas. Both diets induced atypical cell population of tubules in the kidney, but no nephroblastoma.

Photolysis of p-[2-(2-chloromethyl-1,3-dioxolan-2-yl)ethyl]phenol and 1,4-dioxadispiro[4,1,5,2]tetradeca-8,11-dien-10-one gives in good yield 3′,4′-dihydro-7′-hydroxyspiro[1,3-dioxolan-2,2′-(1′H)-naphthalene] which is hydrolysed to 3,4-dihydro-7-hydroxynaphthalen-2(1H)-one.

Irradiation of 2-bromo-N-ethyl-4′-hydroxybenzanilide in aqueous alkali in the presence of sodium borohydride gave in high yield 2′-ethyl-4-hydroxyspiro[cyclohexa-2,5-diene-1,1′-isoindoline]-3′-one, which was oxidised to 2′-ethylspiro[cyclohexa-2,5-diene-1,1′-isoindoline]-3′,4-dione.