Search

ObjectivesTo determine if linear measurements of adiposity from pre-operative imaging can improve anticipation of surgical difficulty among endometrial cancer patients.MethodsEighty patients with newly diagnosed endometrial cancer were enrolled. Routine pre-operative imaging (MRI or CT) was performed. Radiologic linear measurements of the following were obtained: anterior-to-posterior skin distance; anterior skin to anterior edge of L5 distance (total anterior); anterior peritoneum to anterior edge of L5 distance (visceral obesity); and posterior edge of L5 to posterior skin distance (total posterior). Surgeons completed questionnaires quantifying preoperative anticipated operative difficulty and postoperative reported operative difficulty. The primary objective was to assess for a correlation between linear measurements of visceral fat and reported operative difficulty.ResultsSeventy-nine patients had questionnaires completed, preoperative imaging obtained, and surgery performed. Univariate analysis showed all four linear measurements, body mass index, weight, and anticipated operative difficulty were associated with increased reported operative difficulty (P< 0.05). Multivariate analysis demonstrated that body mass index and linear measurements visceral obesity and total posterior were independently associated with increased reported operative difficulty (P< 0.05). Compared with body mass index, the visceral obesity measurement was more sensitive and specific for predicting increased reported operative difficulty (visceral obesity; sensitivity 54%, specificity 91 %; body mass index; sensitivity 38%, specificity 89%). A difficulty risk model combining body mass index, visceral obesity, and total posterior demonstrated better predictive performance than any individual preoperative variable.ConclusionsSimple linear measurements of visceral fat obtained from preoperative imaging are more predictive than body mass index alone in anticipating surgeon-reported operative difficulty. These easily obtained measurements may assist in preoperative decision making in this challenging patient population.

Electrical properties of vertical Schottky diodes fabricated on GaN regrown on hydride vapor phase epitaxy GaN substrates are investigated. The deposition of Ni frames makes it possible to designate the dislocation locations by cathodoluminescence before the fabrication of diodes. Since the distribution of dislocations is inhomogeneous and arranged into clusters over the GaN substrates, diodes made on either areas free of dislocation-clusters or areas with dislocation-clusters have been studied. Both forward and reverse characteristics of diodes fabricated on GaN with different doping levels and dislocation densities have been investigated. It is shown that the reverse leakage is not sensitive to the presence of dislocation clusters. On the other hand, there is a dispersion of reverse leakage which increases in diodes grown on substrates having larger mean dislocation density. The results also demonstrate that a critical maximum distance of around 100 µm between active defects triggers larger reverse leakage currents.

The ITER Ion Cyclotron Resonance Heating (ICRH) system is designed to couple to the plasma 20 MW of RF power from two antennas in the 40-55 MHz frequency range during long pulses of up to 3600 s and under various plasma conditions with Edge Localized Modes. Radio-Frequency (RF) contacts are integrated within the ITER ICRH launcher in order to ensure the RF current continuity and ease the mechanical assembly by allowing the free thermal expansion of the Removable Vacuum Transmission Line coaxial conductors during RF operations or during 250{\textdegree}C baking phases. A material study has been carried out to determine which materials and associated coatings are relevant for RF contacts application in ITER. In parallel, RF tests have been performed with a new prototype of Multi-Contact (r) LA-CUT/0,25/0 contacts made of silver-coated CuCrZr louvers. During these tests on a RF vacuum resonator, currents between 1.2 kA and 1.3 kA peak have been reached a few tens of times in steady-state conditions without any visible damage on the louvers. A final 62MHz pulse ending in a 300s flat top at 1.9kA resulted in severe damage to the contact. In addition, a test bed which performs sliding test cycles has been built in order to reproduce the wear of the contact prototype after 30 000 sliding cycles on a 3 mm stroke at 175{\textdegree}C under vacuum. The silver coating of the louvers is removed after approximately a hundred cycles whilst, to the contrary, damage to the CuCrZr louvers is relatively low., Fusion Engineering and Design, Elsevier, A Para{\^i}tre

The Faraday Screen (FS) is the plasma facing component of ITER ion cyclotron heating antennas shielding. The requirement for the high heat exhaust, and the limitation of the temperatures to minimize strain and thus offer sufficient resistance to fatigue, imply the need for high conductivity materials and a high cooling flow rate. The FS bars are constructed by a hipping process involving beryllium tiles, a pure copper layer, a copper chrome zirconium alloy for the cooling channel and a stainless steel backing strip. Two FS bars small scale mock-ups were manufactured and tested under high heat flux. They endured 15,000 heating cycles without degradation under nominal heat flux, and revealed growing flaws when the heat flux was progressively augmented beyond. In this case, the ultrasonic test confirms a strong delamination of the Be tiles.

There is very little known about the ecology of the aquatic plant Podostemum ceratophyllum (Hornleaf Riverweed) but the few studies that have investigated the ecology of the plant indicate that it is an important component of eastern rivers, increasing resources available to benthic fauna, and influence nutrient cycling. Reductions in Podostemum biomass has been found to substantially decrease macroinvertebrate biomass, which may trigger trophic cascades that negatively impact fishes and other large bodied consumers. Anecdotal evidence indicates that there has been an overall decline in the plant’s population but the causes of decline remains unclear. Collection records of Podostemum date back to the mid 1800’s but few populations have been documented since the 1950’s. This project will resurvey populations of Podostemum ceratophyllum to ascertain the current extent of the plant in West Virginia. Surveys will be accompanied with the collection of water chemistry data to better document the environmental parameters of the plant and help understand the reasons for decline. Better documentation of Podostemum population locations and associated water quality parameters is important for the management and restoration of West Virginia’s rivers and streams. Grant provided by NASA West Virginia Space Grant Consortium, Undergraduate Research Fellowship Program.

India is in-charge for the procurement of ITER Ion Cyclotron Resonance Frequency (ICRF) sources (1 Prototype + 8 series units) along with auxiliary power supplies and Local Control Unit. As there is no unique amplifier chain able to meet the output power specifications as per ITER requirement (2.5 MW per source at 35–65 MHz/CW/VSWR 2.0), two parallel three-stage amplifier chains along with a combiner circuit on the output side is considered. This kind of RF source will be unique in terms of its stringent specifications and building a first of its kind is always a challenge. An R&D phase has been initiated for establishing the technology considering single amplifier chain experimentation (1.5 MW/35–65 MHz/3600 s/VSWR 2.0) prior to Prototype and series production. This paper presents the status of R&D activity to resolve technological challenges involved and various infrastructures developed at ITER-India lab to support such operation.

Embedded RF contacts are integrated within the ITER ICRH launcher to allow assembling, sliding and to lower the thermo-mechanical stress. They have to withstand a peak RF current up to 2.5 kA at 55 MHz in steady-state conditions, in the vacuum environment of themachine.The contacts have to sustain a temperature up to 250{\textdegree}Cduring several days in baking operations and have to be reliable during the whole life of the launcher without degradation. The RF contacts are critical components for the launcher performance and intensive R&D is therefore required, since no RF contactshave so far been qualified at these specifications. In order to test and validate the anticipated RF contacts in operational conditions, CEA has prepared a test platform consisting of a steady-state vacuum pumped RF resonator. In collaboration with ITER Organization and the CYCLE consortium (CYclotronCLuster for Europe), an R&D program has been conducted to develop RF contacts that meet the ITER ICRH launcher specifications. A design proposed by CYCLE consortium, using brazed lamellas supported by a spring to improve thermal exchange efficiency while guaranteeing high contact force, was tested successfully in the T-resonator up to 1.7 kA during 1200 s, but failed for larger current values due to a degradation of the contacts. Details concerning the manufacturing of the brazed contacts on its titanium holder, the RF tests results performed on the resonator and the non-destructive tests analysis of the contacts are given in this paper., Comment: Fusion Engineering and Design, Elsevier, 2015, Available online 21 April 2015

This paper describes a WebGIS prototype developed for the Walloon administration to improve the communication and the management of sediments dredging actions carried out in rivers and lakes. In Wallonia, levelling dredged sediments on banks requires an official authorization from the administration. This request refers to geospatial datasets such as the official land use map, the cadastral map or the distance to potential pollution sources. Centralising geodatabases within a web interface facilitate the management of these authorizations for the managers and the central administration. The proposed system integrates various data from disparate sources. Some issues in map scale, spatial search quality and cartographic visualisation are discussed in this paper with the solutions provided. The prototype web application is currently discussed with some potential users in order to understand in which way this tool facilitate the communication, the management and the quality of the authorisation process. The structure of the paper states the why, what, who and how of this communication tool with a special focus on errors and uncertainties.

The ITER Ion Cyclotron Heating and Current Drive system (IC H&CD) is designed to deliver 20MW to a broad range of plasma scenarios between 40 and 55MHz, during very long pulses. It consists of two broadband equatorial port plug antennas, their pre-matching and matching systems, transmission lines, Radio Frequency (RF) Sources and High Voltage Power Supplies. The overall project schedule has been revised and agreed by ITER Council; it re-integrates the second antenna and its power supplies in construction baseline and sets the dates for progressive installation with DT phase planned in 2035. Recent progress on ICRF subsystems is reported, covering design evolution, qualification of test articles and specific R&D results in domestic agencies, suppliers, associated laboratories and IO.

This paper delineates the concept of Best Practice (BP); demonstrates that the practices of Australian manufactures subscribing to best practice are significantly different from those that do not; and determines whether components of best practice used by industry match components recognized by researchers. A search of the literature for definitions of BP and a statistical analysis of a survey completed by 962 Australian manufacturing sites were used. Most definitions of BP comprise lists of components that vary significantly amongst authors and do not reflect strong theoretical bases but researchers and practitioners use roughly similar definitions. There are significant differences between the strategies and practices of Australian manufacturers that use BP and those that do not. It is difficult to prove that BP causes superior performance. Internal efforts to improve performance may be masked by their lagged effects and events external to the organization. Superior performance might be caused by energetic management in part manifest in BP and other improvement programs. Nevertheless, having a BP program is strongly associated with traits such as proactivity, internal communication, training and leadership that should be commercially advantageous. Manufacturers should therefore consider implementing BP programs. This paper clarifies definitions of BP and conclusively demonstrates that the practices of Australian organizations subscribing to BP are significantly different from those that do not.

Organisations constantly seek improvement of organisational practices or market positions by implementing improvement programs and quality initiatives such as ISO certification. An improvement project is any project that aims to make a business process more efficient, flexible, reliable or responsive; or raise the quality of working life. Notes that few organisations make the effort to evaluate the effectiveness of such improvement programs, explores why this might be so, and describes some of the benefits of undertaking evaluation activities. Presents a methodology for selecting Key Performance Indicators most appropriate to selected business processes and assessing an improvement program, and describes the methodology’s implementation in a small Australian software company. Stresses that measurement of performance before and after ostensible improvements is needed for objective assessment of change processes.

The ITER ion cyclotron heating and current drive system is designed to deliver 20 MW to a broad range of plasma scenarios, during very long pulses (∼500 s in inductive, up to 1 h in noninductive, p...

In the four-stage approach of the new ITER Research Plan, the first pre-fusion power operation (PFPO) phase will only have limited power available from external heating and current drive (H&CD) systems: 20-30 MW provided by the electron cyclotron resonance heating (ECRH) system. Accessing the H-mode confinement regime at such low auxiliary power requires operating at low magnetic field, plasma current and density, i.e. 1.8 T and 5 MA for a density between 40% and 50% of the Greenwald density. II-mode plasmas at 5 MA/1.8 T will also be investigated in the second PFPO phase when ITER will have its full complement of H&CD capabilities installed, i.e. 20-30 MW of ECRH, 20 MW of ion cyclotron resonance heating and 33 MW of neutral beam injection. This paper describes the operational constraints and the II&CD capabilities for such scenarios in hydrogen and helium plasmas, to assess their viability and the issues it will be possible to address with them. The modelling results show that 5 MA/1.8 T scenarios are viable and will allow the exploration of the H-mode physics and control issues foreseen in the ITER Research Programme in the PFPO phases.

Accurate provenance information facilitates improved understanding of Earth science data and scientific reproducibility and can serve as an indicator of data quality. Provenance capture is an integral part of many modern workflow systems but may not have been considered in the design of legacy data production systems. Furthermore, in addition to data lineage, it is also important to capture contextual information needed for understanding how a data set was produced. This paper describes our experience in retrofitting a legacy data system to support capture, storage, and dissemination of provenance. Data inputs and transformations are logged automatically, while broader context information describing science algorithms and ancillary files is manually compiled. Provenance and context information are integrated for interactive user access and embedded into data files as XML documents compliant with the “Lineage” specification for geographic metadata defined by the International Organization for Standardization in the ISO 19115-2 standard. Lessons learned from this approach can inform others who need to incorporate provenance into a data system after the fact.

We investigate the relative transmission and the effective gain of a two-dimensional electron gas (2DEG) in the terahertz (THz) frequency domain. The position of THz source, device, and detector is numerically simulated in order to obtain an optimized experimental configuration. The effect of variation of polarization of incident beam, and geometries of devices is investigated. The inter-digitated finger (IDF) structures of the device under investigation show maximum transmission in direct polarization configuration which is attributed to the metallic polarizing nature of IDFs, and to the effective interaction of the incident THz radiations and the device. This technique should be helpful to measure THz transmission of electronic devices with 2DEG.

To investigate hepatosplenic volumetry at MDCT for non-invasive prediction of hepatic fibrosis. Hepatosplenic volume analysis in 624 patients (mean age, 48.8 years; 311 M/313 F) at MDCT was performed using dedicated software and compared against pathological fibrosis stage (F0 = 374; F1 = 48; F2 = 40; F3 = 65; F4 = 97). The liver segmental volume ratio (LSVR) was defined by Couinaud segments I–III over segments IV–VIII. All pre-cirrhotic fibrosis stages (METAVIR F1-F3) were based on liver biopsy within 1 year of MDCT. LSVR and total splenic volumes increased with stage of fibrosis, with mean(±SD) values of: F0: 0.26 ± 0.06 and 215.1 ± 88.5 mm3; F1: 0.25 ± 0.08 and 294.8 ± 153.4 mm3; F2: 0.331 ± 0.12 and 291.6 ± 197.1 mm3; F3: 0.39 ± 0.15 and 509.6 ± 402.6 mm3; F4: 0.56 ± 0.30 and 790.7 ± 450.3 mm3, respectively. Total hepatic volumes showed poor discrimination (F0: 1674 ± 320 mm3; F4: 1631 ± 691 mm3). For discriminating advanced fibrosis (≥F3), the ROC AUC values for LSVR, total liver volume, splenic volume and LSVR/spleen combined were 0.863, 0.506, 0.890 and 0.947, respectively. Relative changes in segmental liver volumes and total splenic volume allow for non-invasive staging of hepatic fibrosis, whereas total liver volume is a poor predictor. Unlike liver biopsy or elastography, these CT volumetric biomarkers can be obtained retrospectively on routine scans obtained for other indications. • Regional changes in hepatic volume (LSVR) correlate well with degree of fibrosis. • Total liver volume is a very poor predictor of underlying fibrosis. • Total splenic volume is associated with the degree of hepatic fibrosis. • Hepatosplenic volume assessment is comparable to elastography for staging fibrosis. • Unlike elastography, volumetric analysis can be performed retrospectively.

Pargeter and colleagues do not escape the dangers inherent in the exercise they embark on. The first is that of creating a straw man argument in which one exaggerates and misinterprets what was said in the article being criticised. The second is that of using your time to look at the speck of dust in your brother's eye instead of paying attention to the plank in your own. The third, if you are lucky enough to find a sympathetic journal, is to rehash the same criticism over and over in multiple articles, changing the tone from very moderate (Mitchell 2012) to more aggressive (Pargeter 2014), which inevitably pushes your opponents and any sensible reader to wonder about your motivations.

To achieve the overall ITER machine availability target, the availability of diagnostics and heating port plugs shall be as high as 99.5%. To fulfill these requirements, it is mandatory to test the port plugs at operating temperature before installation on the machine and after refurbishment. The ITER port plug test facility (PPTF) provides the possibility to test upper and equatorial port plugs before installation on the machine. The port plug test facility is composed of several test stands. These test stands are first used in the domestic agencies and on the ITER Organization site to test the port plugs at the end of manufacturing. Two of these stands are installed later in the ITER hot cell facility to test the port plugs after refurbishment. The port plugs to be tested are the Ion Cyclotron (IC) heating and current drive antennas, Electron Cyclotron (EC) heating and current drive launchers, diagnostics and test blanket modules port plugs. Test stands shall be capable to perform environmental and functional tests. The test stands are composed of one vacuum tank (3.3 m in diameter, 5.6 m long) and the associated heating, vacuum and control systems. The vacuum tank shall achieve an ultimate pressure of 1 × 10−5 Pa at 100 °C containing a port plug. The heating system shall provide water at 240 °C and 4.4 MPa to heat up the port plugs. Openings are provided on the back of the vacuum tank to insert probes for the functional tests. This paper describes the tests to be performed on the port plugs and the conceptual design of the port plug test facility. The configuration of the standalone test stands and the integration in the hot cell facility are presented.

The RF heating and current drive (H&CD) systems to be installed for the ITER fusion machine are the electron cyclotron (EC), ion cyclotron (IC) and, although not in the first phase of the project, lower hybrid (LH). These systems require high voltage, high current power supplies (HVPS) in CW operation. These HVPS should deliver around 50 MW electrical power to each of the RF H&CD systems with stringent requirements in terms of accuracy, voltage ripple, response time, turn off time and fault energy. The PSM (Pulse Step Modulation) technology has demonstrated over the past 20 years its ability to fulfill these requirements in many industrial facilities and other fusion reactors and has therefore been chosen as reference design for the IC and EC HVPS systems. This paper describes the technical specifications, including interfaces, the resulting constraints on the design, the conceptual design proposed for ITER EC and IC HVPS systems and the current status.

The Ion Cyclotron Heating and Current Drive (IC H&CD) system for ITER will provide 20 MW to the plasma. The associated Radio Frequency (RF) source system has to be compliant with all operation modes foreseen in that frame. Their specifications are fully described in this paper and constraints on IC RF source components are detailed, in particular concerning the final stage tube of the amplifier. Results of tests performed under a collaborative work at the National Institute for Fusion Science (NIFS) facility are presented. Consequences on the procurement process by ITER India (II) are deduced.

Located close to the Kalahari in central South Africa is a large dolomitic cave called Wonderwerk, in the stratified sediments of which there is evidence for fire-making that ranges from the end of the Later Stone Age to the very base of the Acheulean. That discovery is seen to be in accord with findings from four other regional sites, which together provide evidence that can be construed as support for fire-making over almost the same time span.

The RF heating and current drive (H&CD) systems that are to be installed in ITER during the construction phase, are the electron cyclotron (EC) and ion cyclotron (IC) systems. They are complex assemblies of high voltage power supplies (HVPS), RF generators, transmission lines and antennas. Their design and integration are constrained by many interfaces, both internal, between the subsystems, and external, with the other ITER systems. In addition, some components must be compatible with a nuclear environment and are classified as Safety Important Component. This paper describes the processes implemented in ITER to ensure proper integration.

One form of contract bridge tournament comprises several rounds of matches in which players compete as pairs for ‘masterpoints’ awarded for each match won or drawn and for being highly placed at the end of the tournament. In the second and subsequent rounds, pairs are matched against other pairs that have been approximately equally successful so far. There has been vague discussion among bridge players of the possible advantages of ‘throwing’, that is, deliberately losing a match in round r so as to obtain a lower ranking and face an easier opponent in round r+1. This paper uses dynamic programming and data from one tournament to identify an optimal strategy (either ‘throw’ or ‘play to win’). The optimal strategy is a function of a pair's ability, its placing after each round, the relative rewards for winning a match and finishing high, the opponent's skill, and the round. For example, we find that a very weak pair should ‘throw’ and ‘play to win’ in alternate rounds.

This paper examines the extent to which the requirement for confidentiality or secrecy within the arbitral process can be maintained from the commencement of the arbitration to the finalisation of an appeal through the court process in England and Wales. The paper starts from the premise that confidentiality, being allegedly a key factor in arbitration, can, and should, be maintained throughout. It will focus on two leading cases, only one of which is given at the level of the Court of Appeal. The other case was issued by the Privy Council albeit the House of Lords in another name. The paper will touch upon whether parties are properly focusing their minds on preparation of an all-encompassing arbitration agreement, which contains an effective confidentiality clause. Further, it will examine whether the judiciary, while correctly emphasising the need for public interest to be satisfied at all times wherever faults are to be found in the arbitration process yet made by way of somewhat obscure indications to the parties as to how fundamental and continuous confidentiality can be achieved.

A prototype of ICRF antenna based on the load-resilient electrical layout anticipated for ITER has been built at CEA-Cadarache. It consists of two toroidally adjacent resonant double loops (RDLs) based on the conjugate-T concept proposed for the ITER ICRF array. This prototype has been recently validated in Tore Supra plasmas exhibiting fast density perturbations in front of the antenna. This paper reports on the load resilience properties of the antenna prototype, as well as the RF modeling and the commissioning. Significant effort on modeling, coupled to an extensive low power campaign, has allowed characterization of the antenna in both vacuum and plasma loading conditions. Plasma load modelings computed with the code TOPICA – very helpful to set up the matching points on plasmas – are found to be in good agreement with the experimental results. The main studies focus on load resilience properties have been carried out in L-mode plasmas. Supersonic molecular beam injection (SMBI), able to launch a series of very short/dense gas jets at Mach number up to 5, was used to mimic the sudden increases of the antenna coupling provoked by ELMs. The results are found to be in good agreement with RF circuit calculations that include 3D modeling.

Since 1999 and with the help of Institut fur Plasmaphysik (IPP) Garching, we have tested in the Tore Supra (TS) Ion Cyclotron Resonance Heating (ICRH) transmitter, arc security systems based on harmonics detection in a frequency band lower than the generator frequency. These systems have some advantages in comparison with traditional protection systems, which are based on use of a level on the V r / V f (reflected to forward voltage ratio) calculation. After some checking for adjustment, they do not use calculation, calibration with frequency or level. They can use RF signals from directional couplers or probes, so they are fully independent of the measurement systems. The detection bandwidth is independent of the antennae working frequencies. In TS the detection principle is insensitive to the cross talk between the antennae and to the antennae coupling variations. In 2001, we have built three systems based on our prototype in order to improve the protection of the three ICRH antennae Q1, Q2 and Q5. The RF principle used on TS ICRH transmitter is described. The results in the last 4 years on an ICRH transmitter module feeding a TS antenna are summarized and some examples typical signals are given.

The paper reports on latest developments for the ITER Ion Cyclotron Heating and Current Drive system: imminent acceptance tests of a prototype power supply at full power; successful factory acceptance of candidate RF amplifier tubes which will be tested on dedicated facilities; further design integration and experimental validation of transmission line components under 6MW hour-long pulses. The antenna Faraday shield thermal design has been validated above requirements by cyclic high heat flux tests. R&D on ceramic brazing is under way for the RF vacuum windows. The antenna port plug RF design is stable but major evolution of the mechanical design is in preparation to achieve compliance with the load specification, warrant manufacturability and incorporate late interface change requests. The antenna power coupling capability predictions have been strengthened by showing that, if the plasma scrape-off layer turns out to be steep and the edge density low, the reference burning plasma can realistically be displaced to improve the coupling.

International audience; Al, Au, Ti/Al and Ti/Au contacts were prepared on n-GaN and annealed up to 900 °C. The structure, phase and morphology were studied by cross-sectional transmission and scanning electron microscopy as well as by X-ray diffraction (XRD), the electrical behaviour by current–voltage measurements. It was obtained that annealing resulted in interdiffusion, lateral diffusion along the surface, alloying and bowling up of the metal layers. The current–voltage characteristics of as-deposited Al and Ti/Al contacts were linear, while the Au and Ti/Au contacts exhibited rectifying behaviour. Except the Ti/Au contact which became linear, the contacts degraded during heat treatment at 900 °C. The surface of Au and Ti/Au contacts annealed at 900 °C have shown fractal-like structures revealed by scanning electron microscopy. Transmission electron microscopy and XRD investigations of the Ti/Au contact revealed that Au diffused into the n-GaN layer at 900 °C. X-ray diffraction examinations showed, that new Ti2N, Au2Ga and Ga3Ti2 interface phases formed in Ti/Au contact at 900 °C, new Ti2N phase formed in Ti/Al contact at 700 and 900 °C, as well as new AlN interface phase developed in Ti/Al contact at 900 °C.

In ITER, the ion cyclotron heating (ICH) system should routinely and reliably operate at a power level close to the installed power (20 MW) in quasi-continuous operation. The operation will be efficient and reliable only if plasma coupling and absorption of the fast wave on the plasma bulk are optimized, parasitic power losses in the plasma edge minimized, and the RF power flow, from the wave launching structure to the absorption layer, efficiently maintained against the effects of significant load variations. In this paper the ion cyclotron launcher proposed in the ITER Final Design Report (FDR) is briefly reviewed and a number of design changes are proposed, without any modification of the basic layout, in order to simplify construction and maintenance and to improve the performance and reliability of operation.

This paper notes and explains the increasing use of service level agreements (SLAs), stresses their importance to insourcing and outsourcing relationships, proposes a taxonomy of service attributes, and recommends a hierarchical methodology for constructing SLAs. Evidence from interviews and examination of SLA documents suggests that well-designed SLAs contribute to fruitful relationships between business partners. The proposed methodology and taxonomy will simplify the time-consuming tasks of writing and negotiating SLAs. SLAs have not received academic attention proportionate to their commercial importance. Research to ascertain whether SLAs are used effectively and to seek better expression of business requirements in an SLA is appropriate.

In this work AlGaN/GaN high electron mobility transistors have been grown on Silicon (111), Silicon Carbide and GaN templates on Sapphire. Both the structural and the electrical properties of these layers have been studied in order to determine the impact of substrate choice on dislocation density, strain state, roughness and electron mobility.

An ICRF antenna coupled to the plasma presents a load impedance different from what the generator requires for optimal power transfer. The required matching must be able to accommodate changes in coupling impedance due to varying plasma conditions. The changes occur on a timescale varying between particle confinement time and MHD events. In ELMy plasmas, the latter can be as fast as 50 μs. Several methods are in use, but only a few can cope with this most challenging condition: hybrid couplers and conjugate-T. Hybrid couplers have been implemented on ASDEX Upgrade, Double-III-D and will be on JET, while Alcator C-mod, JET, Textor and Tore Supra have been outfitted with conjugate-T.

One of the main Tore Supra objectives is to produce long and high performance discharges, studies which are crucial for the next step. In the frame of the CIMES project, associated with the manufacture of an ITER relevant PAM launcher, a new klystron is under development at Thales Electron Devices. The upgrade will lead to an installed power of 12 MW in the lower hybrid transmitter. Each of the 16 tubes will work at 3.7 GHz, 76 kV, 22 A with an efficiency up to 45%, providing 700 kW on a VSWR up to 1.4, during 1000 s. Two factory prototypes have been manufactured and tested on the Thales test bed. The first one is installed on Tore Supra Lower Hybrid test bed. Up to now, 770 kW at 75 kW, 22 A (50% duty cycle) have been achieved on matched load. A prototype, derived from these two factory prototypes, will reach full performance in few months. The tube's parameters are described in this paper. They are compared to those of the TH2103 presently used in the transmitter and their choices are detailed and explained. The results obtained with prototypes as well as the technological difficulties are presented and analysed.

One particularity of Tore Supra is that the plasma facing components (PFCs) are actively cooled, allowing research on long duration and high energy discharges. During a discharge, a large part of the energy dissipated in the heating generators (ICRH, ECRH and LHH) and auxiliaries is transferred to the primary cooling loops (B50 and B60). The energy, which is injected in the plasma, is totally recovered by the PFCs primary cooling loop B30. The primary loops are cooled via heat exchangers by a secondary loop. The previously existing limitations of the complete Tore Supra cooling system were due to the heat exchange performance to the secondary loop. From 2001 to 2003, the various primary loops have been upgraded and during the 2003 experimental campaign, significant results were obtained, particularly during non-inductive discharges with an injected energy by the lower hybrid current drive (LHCD) system of up to 1.1 GJ. For the long and high energy discharges, the agreement between the thermal energy exhausted from the PFCs and measured by the calorimetry and the energy injected in the plasma is very good (90–95%). Furthermore, calorimetry measurements on the various cooling loops allow to assess the global operation of the cooling system.

Power switching in RF heating systems is a delicate function as it is often linked to high power tube protection. In most RF systems, the end stage power tube is fed by a high voltage power supply (HVPS), which connection to the tube has to be interrupted in case of arc suspicion. The amount of energy that is allowable to be dissipated in the arc is in the range of 10–50 J, to limit the degradations observed on the tube structures. The protection function is usually performed by a crowbar. Furthermore, the HVPS is often shared by several power tubes, and the loss of all the power from the group of tubes is to be avoided to minimize the perturbation on the plasma experiment. A description of a 40 kV thyristor based crowbar and a 100 kV, 25 A MOSFET switch is given, as well as the contours of the existing components for high power switching applications. By combining small components, such as thyristors or MOSFET, in matrix, highly compact and reliable units have been built and implemented in Tore Supra RF systems.

The project of an ITER-like (IL) ion cyclotron (IC) prototype antenna was initiated in mid 2002 in Cadarache, to assess the operational characteristics of the IL scheme in a Tore Supra (TS)-sized array. The prototype was developed by modifying an existing Tore Supra resonant double loop (RDL) antenna. This strategy, chosen to reduce cost and manufacturing time, allowed the completion of the array construction at the end of 2003. The array was installed on TS in January 2004, at the beginning of the new experimental campaign. After a few comments on the design, the paper reports results on low-power characterisation, high-power commissioning and preliminary tests on TS plasmas, prior to the array dis-assembly for inspection.

The effect of native and radiation induced defects on the photoconductivity transients and photoluminescence spectra have been examined in GaN epitaxial layers of 2.5 and 12 μm thickness grown on bulk n-GaN/sapphire substrates by metal-organic chemical vapor deposition (MOCVD). For comparison, free-standing GaN as-grown samples of 500 μm thickness, fabricated by hydride vapor phase epitaxy (HVPE), were investigated. Manifestation of defects induced by 10-keV X-ray irradiation with the dose of 600 Mrad and 100-keV neutrons with the fluences of 5×1014 and 1016 cm−2 as well as of 24 GeV/c protons with fluence 1016 cm−2 have been revealed through contact photoconductivity and microwave absorption transients. The amplitude of the initial photoconductivity decay is significantly reduced by the native and radiation defects density. Synchronous decrease of the steady-state PL intensity of yellow, blue and ultraviolet bands peaked at 2.18, 2.85, and 3.42 eV, respectively, with density of radiation-induced defects is observed. The decrease of the PL intensity is accompanied by an increase of asymptotic decay lifetime in the photoconductivity transients, which is due to excess-carrier multi-trapping. The decay fits the stretched exponent approximation exp[-(t/τ)α] with the different factors α in as-grown material (α≈0.7) and irradiated samples (α≈0.3). The fracton dimension ds of disordered structure changes from 4.7 to 0.86 for as-grown and irradiated material, respectively, and it implies the percolative carrier motion on an infinite cluster of dislocations net in the as-grown material and cluster fragmentation into finite fractons after irradiations.

A 3.7-GHz 750-kW klystron in continuous-wave (CW) operation is under development to upgrade the lower hybrid RF power of Tore Supra up to 12 MW. Four different operating modes are required: diode regime (1680-kW dc of beam power in the collector), 750-kW RF on matched load, 700-kW min all phases on voltage standing wave ratio (VSWR) 1.4:1 (plasma conditions), and around 400-kW pulsed mode on VSWR 3.0:1 (for antenna conditioning phase). The klystron is equipped with a diode type electron gun, a five-cavity RF structure with a highly efficient cooling system for the output cavity, a single tapered waveguide, a single BeO disc RF window, and a large diameter hypervapotron collector. Two breadboard models have been built and tested. At 50% duty cycle (with 5-ms pulse length), an RF output power of 770 kW has been measured at a beam voltage of 75 kV and a beam current of 22 A. The efficiency is 46.6% and the gain is 54 dB. On VSWR 1.4, a minimum output power of 660 kW has been obtained and the klystron is stable at all phases. In CW operation, the klystron has produced an output power of 680 kW. The limitation is due to excessive body power. The final prototype with an improved beam optics and thermal design will be ready in the second half of the year 2004.

On soutient souvent que les industries de « haute technologie » dans les économies industrialisées les plus développées regroupent une forte proportion d'entreprises non syndiquées. Ceci, en retour, a été attribué au fait que celles-ci possèdent des politiques sophistiquées de gestion des ressources humaines qui génèrent un « effet de substitution » au syndicalisme. Cependant, ces prétendues relations sont davantage des actes de foi que des propositions empiriques bien établies. En effet, la recherche, à l'heure actuelle, semble comporter des faiblesses de fond et de méthodologie soit, en particulier : 1) le défaut d'une définition explicite et compréhensive des industries de haute technologie; 2) l'absence d'un ensemble de données établies comme base d'analyse qui soient valables pour tout le pays; 3) le défaut d'examiner ce type de relations en recourant, ceteris paribus, à l'utilisation de l'analyse multivariée.Le présent article s'efforce de remédier aux déficiences actuelles de la recherche en Grande-Bretagne où les débats concernant le syndicalisme dans les industries de haute technologie se sont toujours limités à des études courtes et partielles tirées de l'industrie de l'électronique. L'analyse se fonde d'abord sur la définition « officielle » des industries de haute technologie telle que fixé par le ministère du Commerce et de l'Industrie qui s'appuie sur le degré relatif de dépenses en recherche et en développement et sur la proportion de scientifiques, ingénieurs et techniciens par rapport à l'ensemble de la main-d’œuvre. L'utilisation de cette définition par les chercheurs comporte l'avantage de pouvoir comparer les résultats de leurs études. Toutefois, on a toujours exprimé certaines réserves au sujet de l'utilisation du concept de haute technologie au niveau de l'industrie par opposition aux analyses au niveau de l'entreprise. Pour ce motif, on a eu recours à une deuxième mesure de la haute technologie dans un certain nombre d'analyse multivariee. Il s'agit du pourcentage d'emplois manuels par entreprise (compare aux estimations moyennes pour le secteur prive) engage dans la fabrication de produits ou l'utilisation de processus qui comportent l'emploi de micro-ordinateurs. Ces deux définitions de la haute technologie ont donné des valeurs vaguement interreliées (r = — . 116).La source principale de statistiques utilisées dans l'analyse provient d'une enquête effectuée en 1984 concernant les relations professionnelles sur les lieux du travail. Il s'agit de la recherche la plus récente et la plus représentative au pays en matière d'accords structures en relations du travail pour les entreprises considérées individuellement. L'échantillon global recouvre l'examen de plus de 2 000 établissements, mais notre analyse se confine au secteur privé qui touche un sous-échantillon d'environ 1 300 entreprises. L'étude des facteurs déterminants de la reconnaissance syndicale par un modèle promit révèle que la définition officielle de la haute technologie (c'est-à-dire pour l'ensemble de l'industrie en tenant compte des produits fabriques) est reliée de façon positive et significative à la non-syndicalisation des travailleurs manuels. Par contre, la deuxième définition ou mesure (c'est-à-dire établissements individuels où l'on considère les processus de production) est reliée d'une manière significative mais négative à une situation de non-syndicalisation. Ces résultats statistiques différents sont importants puisqu'ils révèlent la nécessité pour les chercheurs d'être très clairs et précis à propos de la définition et de la mesure de la haute technologie utilisée dans une analyse des rapports possibles avec l'état de la syndicalisation.Au sujet de la relation positive entre la définition officielle de la haute technologie et la non-existence des syndicats, nous avons ensuite considéré le rôle possible de la politique de gestion des ressources humaines dans une telle relation. Bien que nous manquions de renseignements sur l'ensemble des politiques individuelles typiquement identifiées dans les discussions théoriques concernant les systèmes de gestion des ressources humaines, nos données contenaient trois variables utiles à cette fin : l'existence (ou non) d'un comité consultatif paritaire; un régime de partage des bénéfices; la présence (ou non) récente d'un régime quelconque de participation des employés. L'utilisation de l'analyse discriminante a révélé que les comités consultatifs paritaires et les régimes récents de participation des travailleurs étaient positivement relies aux établissements de l'industrie de haute technologie, tandis que les systèmes de participation aux bénéfices étaient négativement reliés à ces établissements.Toutefois, dans ce dernier cas, il n'y avait pas de différenciation marquée à l'intérieur des industries de haute technologie entre les établissements syndiques et ceux qui ne l'étaient pas. Ceci laisse voir que ou bien il faut des renseignements de meilleure qualité et plus approfondis sur la nature de ces variables et mettre au point un nouvel ensemble de variables pour les régimes de gestion des ressources humaines; ou bien, la non-syndicalisation des entreprises dans les industries de haute technologie n'est pas un phénomène homogène relie au concept même des systèmes de gestion des ressources humaines. Ces diverses explications possibles font nettement ressortir la nécessité de recherches complémentaires plus détaillées sur cette question., This paper seeks to remedy some existing research deficiencies in Britain where discussions of the high technology non-union relationship have overwhelmingly consisted of small partial studies of the electronics industry.