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Excitation using surface acoustic waves (SAW) has demonstrated efficacy in improving microscale particle/chemical transport due to its ability to generate microscale wavelengths. However, the effects of acoustic stimulation on transport processes along the length of sub-wavelength microchannels and their underlying mechanisms, essential for long-range transport, have not been examined in detail. In this work, we investigate diffusion along the length of subwavelength microchannels using experimental and simulation approaches, demonstrating enhanced transport under SAW excitation. The microchannel-based enhanced diffusion mechanisms are further studied by investigating the acoustic pressure and streaming fields, finding that the degree of enhancement is a function of applied power, microchannel dimensions, and viscosity. This microchannel-based diffusion enhancement approach is applicable to microfluidic and biomedical microscale transport enhancement, with the findings here being relevant to acoustic-based micro-mixing and neurodegenerative therapies.

Imaging diagnostics in Joint European Torus have become essential in the study of plasma wall interactions and the protection of the plasma facing components. During deuterium operations, the location of these diagnostics was at close proximity to the vessel. However, for the 50–50 deuterium-tritium operation, the neutron yield impact onto the electronics of these imaging diagnostics would have caused them to fail completely at these locations. Shielding these systems from neutrons is achieved by relocating a selected number of these imaging systems to outside the Torus Hall (i.e. to the other side of the biological shield wall). The relocation encompasses the construction of two new lines of sight crossing through the biological shield wall and each of them using an optical relay which extends to separate ports in the machine. This article starts with a brief description of two new viewing systems. However, it focuses on the optical modelling and engineering design of one of them which is a multiple camera system producing a wide angle view (WAV) of the inside of the vessel. This WAV system has been used successfully during the recent D-T campaign. It operates in a broadband wavelength range extending from the visible to the middle infrared. It also incorporates a novel in-house horizontal kinematic mirror mount made from glass reinforced plastic as part of the optical relay. The operational stability of the WAV system has also been assessed and some post design improvements implemented.

Investigating cell adhesion behavior on biocompatible surfaces under dynamic flow conditions is not only of scientific interest but also a principal step towards development of new medical implant materials. Driven by the improvement of the measurement technique for microfluidic flow fields (scanning particle image velocimetry, sPIV), a semi-automatic correlation of the local shear velocity and the cell detachment probability became possible. The functionality of customized software entitled ‘PIVDAC’ (Particle Image Velocimetry De-Adhesion Correlation) is demonstrated on the basis of detachment measurements using standard sand-blasted titanium implant material. A thermodynamic rate model is applied to describe the process of cell adhesion and detachment. A comparison of the model and our experimental findings, especially in a mild regime, where the shear flow does not simply tear away all cells from the substrate, demonstrates, as predicted, an increase of detachment rate with increasing shear force. Finally, we apply the method to compare experimentally obtained detachment rates under identical flow conditions as a function of cell density and find excellent agreement with previously reported model simulations that consider pure geometrical effects. The demonstrated method opens a wide field of applications to study various cell lines on novel substrates or in time dependent flow fields.

Objectives This study aimed to assess the impact of different abutment materials on peri-implant tissue regeneration after surgical treatment of peri-implantitis in a large animal model. Material and Methods Titanium implants ( n = 51) were inserted in the upper and lower jaw of eight beagle dogs and a peri-implant infection was induced. After two months the peri-implant infection was surgically treated and abutments with different surfaces (Ti-2: n = 14; CoCrMb: n = 13; Ag-modified Ti-4: n =14; Ti-4 control: n = 10) were applied. Clinical attachment level (CAL), modified sulcus bleeding index (mBI), bleeding on probing (BoP), and the sulcus fluid flow rate (SFFR) were determined 4, 8, and 12 weeks after surgical treatment to document the peri-implant tissue reaction. Results Superior levels for CAL and mBI were found with the Ti-4 control and the Ag-modified abutments, with the Ag-modified abutments showing the best values after 12 weeks. Lowest SFFR values compared with the other treatment groups underlined the superior soft tissue reaction adjacent to Ag-modified abutments. After 12 weeks inferior CAL, SFFR, BOP and mBI values were documented for the Ti-2 surface. Conclusion Within limitations of the study, Ag-modified abutments lead to superior tissue reactions. Further studies are needed to investigate the properties of abutment materials.

Investigating cell adhesion behavior on biocompatible surfaces under dynamic flow conditions is not only of scientific interest but also a principal step towards development of new medical implant materials. Driven by the improvement of the measurement technique for microfluidic flow fields (scanning particle image velocimetry, sPIV), a semi-automatic correlation of the local shear velocity and the cell detachment probability became possible. The functionality of customized software entitled 'PIVDAC' (Particle Image Velocimetry De-Adhesion Correlation) is demonstrated on the basis of detachment measurements using standard sand-blasted titanium implant material. A thermodynamic rate model is applied to describe the process of cell adhesion and detachment. A comparison of the model and our experimental findings, especially in a mild regime, where the shear flow does not simply tear away all cells from the substrate, demonstrates, as predicted, an increase of detachment rate with increasing shear force. Finally, we apply the method to compare experimentally obtained detachment rates under identical flow conditions as a function of cell density and find excellent agreement with previously reported model simulations that consider pure geometrical effects. The demonstrated method opens a wide field of applications to study various cell lines on novel substrates or in time dependent flow fields.

A novel, ultrasound based approach for the dynamic stimulation and promotion of tissue healing processes employing surface acoustic waves (SAW) on a chip is presented for the example of osteoblast-like SaOs-2 cells. In our investigations, we directly irradiate cells with SAW on a SiO2 covered piezoelectric LiNbO3 substrate. Observing the temporal evolution of cell growth and migration and comparing non-irradiated to irradiated areas on the chip, we find that the SAW-treated cells exhibit a significantly increased migration as compared to the control samples. Apart from quantifying our experimental findings on the cell migration stimulation, we also demonstrate the full bio compatibility and bio functionality of our SAW technique by using LDH assays. We safely exclude parasitic side effects such as a SAW related increased substrate temperature or nutrient flow by thoroughly monitoring the temperature and the flow field using infrared microscopy and micro particle image velocimetry. Our results show that the SAW induced dynamic mechanical and electrical stimulation obviously directly promotes the cell growth. We conclude that this stimulation method offers a powerful platform for future medical treatment, e.g. being implemented as a implantable biochip with wireless extra-corporal power supply to treat deeper tissue.

Beryllium (Be) erosion has been studied in dedicated limiter discharges in JET with the recently installed ITER-like wall [1] . Passive spectroscopy [2] in the vicinity of the solid Be limiter is used for measurement of the Be physical sputtering as the main erosion mechanism. To consider the 3D configuration of plasma parameters and the electromagnetic field, the actual limiter shape and the local transport affecting the fraction of Be coming into the observation volume, a detailed modelling with the ERO code has been applied to interpret the experimental data. The observed dependence of BeI and BeII line intensities on plasma parameters during the density scan and various line ratios are used to validate the model and the underlying data including the recently introduced assumptions for Be physical sputtering, the very same which were used before for ITER predictive modelling [3] .

In this contribution we present results from the first N2 seeding experiments in JET performed after installation of the ITER-like Wall. Gas balance measurements for seeded L-mode discharges indicate very strong N2 retention as well as a potential increase in D2 retention. The possible influence of ammonia production on this apparent retention is discussed. Plasma parameters and impurity content were monitored throughout the seeded discharges as well as during subsequent clean-up discharges. These experiments give first insight into phenomena related to the use of nitrogen as seeding gas in JET with the ITER-like Wall, such as ammonia production and nitrogen legacy. © 2013 Elsevier B.V. All rights reserved.

Cell adhesion processes are of ubiquitous importance for biomedical applications such as optimization of implant materials. Here, not only physiological conditions such as temperature or pH, but also topographical structures play crucial roles, as inflammatory reactions after surgery can diminish osseointegration. In this study, we systematically investigate cell adhesion under static, dynamic and physiologically relevant conditions employing a lab-on-a-chip system. We screen adhesion of the bone osteosarcoma cell line SaOs-2 on a titanium implant material for pH and temperature values in the physiological range and beyond, to explore the limits of cell adhesion, e.g., for feverish and acidic conditions. A detailed study of different surface roughness Rq gives insight into the correlation between the cells’ abilities to adhere and withstand shear flow and the topography of the substrates, finding a local optimum at Rq = 22 nm. We use shear stress induced by acoustic streaming to determine a measure for the ability of cell adhesion under an external force for various conditions. We find an optimum of cell adhesion for T = 37 °C and pH = 7.4 with decreasing cell adhesion outside the physiological range, especially for high T and low pH. We find constant detachment rates in the physiological regime, but this behavior tends to collapse at the limits of 41 °C and pH 4.

Systematic scans using D 2 gas puffing and impurity-seeding (Ne, N 2 ) have been carried out on ELMy-H and Advanced-Tokamak-like discharges to study power deposition amelioration at the divertor target plates in preparation for the JET ITER-Like Wall (ILW). Hereby it has been discovered that the recycling ion fluxes I div to the outer target plate exhibit a clear connection to pedestal n e and T e , whereby the D α photon flux Φ Dα from the outer divertor serves here as an approximate measure of I div . Φ Dα can be expressed as ( n e / T e ) β with β = 2.5/3 depending on the scenario (EH/AT). This coupling between SOL and pedestal across the edge transport barrier (ETB) is associated with a close connection between n e and T e in the ETB over the entire range of operational parameters, with the slope of log T e vs. log n e being ∼0.9/1.24 for ET/AT scenarios, respectively.

Tissue engineering for the purpose of nerve or spinal cord repair has become an emerging topic in biophysical and medical research. Addressing this issue relies on an understanding of the principles of tissue growth and applying this understanding to produce functional replacement tissues for clinical use after injury. During wound healing, the damaged tissue layer is reassembled and regenerated through cell proliferation and migration. Thus, any type of external stimuli being able to improve this process of cell regeneration could be highly useful for accelerating wound repair. To study such an external wound healing parameter, we use surface acoustic waves (SAW) for dynamic in vitro manipulation of living cells in a precise controlled manner. In our investigations, we use osteoblastic SaOs-2 cells on a Si02-covered piezoelectric LiNbO3 substrate which we irradiate with SAW continuously for 72hours. Employing a conventional wound healing assay, we show the SAW - treated cells exhibit significantly increased proliferation and migration, respectively, as compared to control samples. Apart from quantifying our experimental findings, we also demonstrate the biocompatibility and biofunctionality of our SAW reactor by using LDH assays. We can neglect parasitic or beneficial side effects such as changing substrate temperature or nutrient flow rate through (OR ‘by closely’) monitoring the temperature and flow field using infrared microscopy and micro particle image velocimetry. Indeed, our results show that the SAW-induced dynamic, mechanical, and electrical stimulation directly promotes cell growth by increasing cell regeneration and migration rates. Our next goal is to guide the cells along certain tracks using hydrophobic/hydrophilic trails in combination with SAW.

L'auteur traite d'abord de l'augmentation assez spectaculaire du nombre d'élèves dans les écoles secondaires pendant les décennies 1919-1939 pour ensuite s'interroger sur les causes et effets de cet état de chose. Deux provinces, l'Ontario et l'Alberta, lui servent de points d'observation, l'une représentant la société déjà industrialisée de l'est, l'autre, celle plus jeune et plus rurale de l'ouest. Comment donc s'explique cette forte montée de la population étudiante? Deux facteurs se distinguent comme étant nettement plus importants : celui du progrès technique qui réduit de beaucoup le besoin d'une main d'oeuvre non-spécialisée d'une part, et, d'autre part, celui du fait que la société semble de plus en plus consciente du rôle de surveillance et de direction que l'école peut assumer dans la vie de l'étudiant. Les effets sont tout aussi marquants. Durant les années vingt, on voit se multiplier les écoles de métiers ainsi que les écoles techniques et commerciales. De même, les activités parascolaires se diversifient et il y a peu d'écoles qui n'ait son conseil étudiant, son journal, son annuaire, ou encore, ses compétitions sportives. Cependant, il n'en demeure pas moins que, dans la majorité des écoles, le programme académique change peu et qu'il est toujours dressé en fonction du petit nombre d'élèves qui se dirige vers l'université. Ces changements s'observent tant en Ontario qu'en Alberta bien qu'ils s'effectuent plus lentement dans cette dernière. Pendant les années trente, le nombre toujours grandissant d'étudiants amène des changements plus radicaux. Dans l'ouest du pays, on adopte bientôt une nouvelle formule où les septième, huitième et neuvième années sont considérées comme un tout servant d'intermédiaire entre l'école élémentaire et l'école secondaire. Cette formule ne sera pas acceptée en Ontario; on optera plutôt pour de plus nombreuses options de cours au niveau de la neuvième année. Autres changements : on se ralliera à une école qui abrite tous les secteurs sous le même toit, et de plus, on abolira les examens dits "d'entrée" pour se tourner du côté du système des "recommandations". En somme, l'école secondaire de 1939 est différente de celle de 1919 tant au qualitatif qu'au quantitatif.

Over the past few years, the preparation of ITER-relevant plasma scenarios has been the main focus of experimental activity on tokamaks. The development of integrated, simultaneous, real-time controls of plasma shape, current, pressure, temperature, radiation, neutron profiles and also impurities, ELMs and MHD are now seen to be essential for further development of quasi-steady state conditions with feedback, or the stabilisation of transient phenomena with event-driven actions. For this thrust, the EFDA JET Real-Time Project has developed a set of real-time plasma measurements, experiment control and communication facilities. The plasma diagnostics used for real-time experiments are Far Infra Red interferometry, polarimetry, visible, UV and X-ray spectroscopy, LIDAR, bolometry, neutron and magnetics. Further analysis systems produce integrated results, such as temperature profiles on geometry derived from MHD equilibrium solutions. The actuators include toroidal, poloidal and divertor coils, gas and pellet fuelling, neutral beam injection, radio frequency (ICRH) waves and microwaves (LH). The heating/fuelling operators can either define a power or gas request waveform or select the real-time instantaneous power/gas request from the real-time experiment central control (RTCC) system. The real-time experiment control system provides both a high-level, control-programming environment and interlocks with the actuators. A MATLAB facility is being developed for the development of more complex controllers. The plasma measurement, controller and plant control systems communicate in ATM network. The EFDA Real-Time Project is essential groundwork for future reactors such as ITER. It involves many staff from several institutions. The facility is now frequently used in experiments. This work has been conducted under the European Fusion Development Agreement and is partly funded by Euratom and the UK Engineering and Physical Sciences Research Council.

Data from a large commercial-scale experiment in which 10 major broiler producer companies stocked whole houses of birds at 30, 34, 38, 42, and 46 kg/m2 were analyzed to identify 1) temperature and humidity profiles achieved throughout the growth cycle, 2) management practices and equipment that contributed to observed variation in environmental conditions, and 3) the extent to which environmental variables affected bird welfare. The study involved a total of 2.7 million birds in 114 houses on commercial farms with measurement of a wide range of environmental and bird variables. Much of the variation in broiler health and welfare was associated with the percentage of time a company could maintain house temperature and RH within limits recommended by the breeder company. RH in the first week of life was particularly important to later health, suggesting that better control of humidity might lead to improved welfare. Key management factors affecting bird welfare were those relating to good ventilation and air control such as the type of ventilation, type of drinker, numbers of stockmen, and litter type. Controlling the environment, particularly temperature, humidity, and air and litter quality, is crucial to broiler chicken welfare. This does not mean that stocking density is unimportant, but lowering stocking density on its own, without regard to the environment the birds experience, is not sufficient. Genuine improvements in bird welfare will come from setting standards that combine stocking density, safeguards on the environment, and the genetic makeup of the birds.

At JET the properties of deuterium molecules and their contribution to the total deuteron flux in the outer divertor for the horizontal configuration in L- and H-mode conditions have been determined. For this purpose the outer divertor was observed with several high resolution spectrometers and lines of sight directed vertically with spatial resolution from the outer vertical target plate to the centre of the MK IIB GB/SRP divertor. The rovibrational population of the Fulcher bands of the deuterium molecules could both be measured for the first five diagonal vibrational transitions. A collisional-radiative model for deuterium molecules was used to convert the measured photon fluxes into local molecular D2-fluxes. With more than 70% of the total proton flux originating from molecular sources molecules make up a significant contribution to the fuelling in the divertor. This was found to be in agreement with the 2d-fluid/neutral particle code EDGE2D/NIMBUS.

The injection of nitrogen, as well as other species generally considered as scavengers of the film precursors, in carbon deposition plasmas can completely inhibit the film formation under given plasma conditions, as it has been extensively shown in technical plasmas. Experiments aimed at using this technique to the suppression of tritium/carbon co-deposits in fusion devices have been initiated in several devices. To date, a moderate inhibition (∼40%) of carbon deposition efficiency has been detected in nitrogen-seeded Elmy plasmas at JET. In addition to this, the divertor plasma simulator, Pisces-B, has been used to benchmark the concept under divertor conditions, while maintaining a better control of the experimental parameters. In the present work a review of the state of the art is given. The results from the available experiments are critically analysed in view of the present understanding of the re-deposited film formation in divertors.

In a collaboration of eight experiments the dependence of the chemical erosion yield of carbon on the ion flux, Φ , was established to Φ −0.54 at high ion fluxes. With this flux dependence a comprehensive description for chemical erosion is available as function of energy, temperature and flux. With this description the erosion and re-deposition of carbon in the ITER divertor can be calculated using the ITER steady-state plasma scenario and the ERO code. The resulting gross and net erosion rates during steady-state phase of discharges are compared to previous estimates using a constant erosion yield of 1.5%. The use of the complete parameter dependence results in an order of magnitude lower erosion, and, accordingly, of the T codeposition inventory.

An overview is given of the experimental method, the analysis technique and the results for trace tritium experiments conducted on the JET tokamak in 2003. Observations associated with events such as sawtooth collapses, neo-classical tearing modes and edge localized modes are described. Tritium transport is seen to approach neo-classical levels in the plasma core at high density and low q(95), and in the transport barrier region of internal transport barrier (ITB) discharges. Tritium transport remains well above neo-classical levels in all other cases. The correlation of the measured tritium diffusion coefficient and convection velocity for normalized minor radii r/a = [0.65, 0.80] with the controllable parameters q95 and plasma density are found to be consistent for all operational regimes (ELMy H-mode discharges with or without ion cyclotron frequency resonance heating, hybrid scenario and ITB discharges). Scaling with local physics parameters is best described by gyro-Bohm scaling with an additional inverse beta dependence.

The chemical erosion of carbon in interaction with a hydrogen plasma has been studied in detail in ion beam experiments, and erosion yield values are available as a function of ion energy and surface temperature. However, the conditions in the ITER divertor cannot be simulated by ion beam experiments, especially as far as ion flux is concerned.Therefore, a joint attempt was made through the EU Task Force on plasma-wall interaction and the international tokamak physics activity involving seven different fusion devices and plasma simulators to clarify the flux dependence. For each data point the local plasma conditions were normalized to an impact energy of 30 eV, care was taken to select data for a surface temperature close to the maximum yield or room temperature and the calibration of the diagnostic was performed in situ. Through this procedure the previous large scatter was significantly reduced, revealing a clear trend for a decreasing yield with increasing ion flux, Phi. After the attribution of an error to each data point a fit using Bayesian probability analysis was performed, yielding a decrease in the erosion yield with Phi(-0.54) at high ion fluxes.

We present results obtained from modeling the septum assessment experiments of the JET MkIIGB divertor with the B2-Eirene code package. Similar L-mode discharges have been performed with and without septum, varying density and gas puffing location. High and low inner wall clearance simulations are also compared, as this parameter has been shown experimentally to play an important role in the final density limit. According to the simulations, the neutrals ionization pattern is not affected by the septum, consistent with experiment. The septum does improve the pumped particle flux in the outer divertor, the inner divertor results depending on plasma-wall clearance, but this only concerns a small fraction of the recycling flux at the targets (less than 2%) and does not influence the overall divertor plasma very much. Comparison between inner and outer gas fuelling with a moderate gas puff rate shows no difference in the simulations without septum, while a slight asymmetry is observed in the simulations with septum, showing that the septum allows acting separately on the inner and outer divertor. We conclude that a neutral flow exists linking outer and inner diveriors with particles travelling around the plasma in the main chamber. (C) 2004 WILEY-VCH Verlag, GmbH & Co. KGaA. Weinheim.

A 2D-tomographic reconstruction of D α - and C III-emission distribution in L-mode, density limit discharge has been performed and compared with results from other diagnostics (KL2, KS3). The observed emission patterns in a poloidal plane show a strong in–out asymmetry, which depends on local plasma parameter in the divertor. It is shown that the major contribution to D α -emission, under the observed conditions, lies in excitation processes and that low-energy charge-exchange reactions with neutral deuterium can influence the ionisation balance of carbon and the recorded C III-emission line. The evolution of the intrinsic hydrogen and carbon impurity profiles has been analysed with respect to its dependence on the location of methane fuelling.

Unsaturated spirocyclic substrates bearing two alkenyl chains underwent ruthenium-mediated ring-rearrangement metathesis through relaying cyclohexene and cycloheptene moieties to give angularly fused tricyclics. In some instances where two products were expected, high degrees of selectivity were observed. In one instance the structural parameter leading to selectivity was very subtle; in others the transformation favoured the formation of products with a cis-fused cyclohexene moiety. An unusual transformation involving ring-opening, double-bond migration, and then ring-closing was observed.

Experiments have been performed to disentangle the individual role of tipper and lower triangularity on density buildup of lower single null, type-I ELMy H-mode discharges in JET. Comparison with corresponding data from ASDEX Upgrade allowed us to determine a dimensionless representation of the relation between the main chamber recycling and core density and to widen the triangularity variation in the data base. To incorporate the recycling flux density F in a dimensionless form, an effective scrape-off layer density n(e,SOL) proportional to Gamma(0.5) is introduced allowing us to,,SOL parametrize and scale the core density by the density rise factor (n) over bar (e)/n(e,SOL). The scaling uses edge-specific definitions of normalized Larmor radius, collisionality and beta. Rewritten in dimensional form, a behaviour is found which is very similar to energy confinement scalings for the ELM-averaged conditions considered here: the density rise factor exhibits an almost linear dependence on plasma current, a weak negative toroidal field dependence as well as power degradation. While a pronounced positive dependence of density buildup on the upper triangularity is observed, no significant correlation with the lower triangularity is found. In particular the dependences on plasma current and upper triangularity emphasize the importance of transport physics for the density buildup.

It is shown statistically that, divertor closure, plasma shaping and density peaking improve the energy confinement of ELMy H-modes, whilst the confinement degrades as the Greenwald density limit is approached. A prediction of the influence of these effects on the next step device ITER is given.

The design value for ITER is based on operation at n/n(GW) = 0.85, beta(n) = 1.8 and H98(y, 2) = 1. These values have been routinely achieved in JET in argon seeded ELMy H-mode discharges in different divertor configurations and with different triangularities. Two main scenarios are emerging from the experiments.First, low triangularity (delta(u) = 0.19) in septum configuration. In this case large D-2 fuelling rates lead to confinement degradation towards L-mode. The seeding of Ar during the D-2 fuelling phase gives rise to a density close to the Greenwald value. After the switch-off of the D-2 gas fuelling ('afterpuff ' phase), the confinement recovers to H-mode quality whereas the density stays near the value reached at the end of the main fuelling phase and Z(eff) stays close to or below 2. Acting on the refuelling of Ar and D-2 in the 'afterpuff 'phase allows us to improve the stationarity of the high performance phase while maintaining up to the end of the heating phase the good confinement, density and radiation level.Second, high triangularity (delta(u) = 0.45) in vertical target configuration. In this case large fuelling rates do not lead to strong confinement degradation and the D-2 fuelling is applied continuously throughout the discharge. A radiated power fraction of up to 70%, H98(y, 2) = 0.9 at beta(n) = 2.1 and n = 1.15n(GW)-together with the formation of a radiating mantle and moderate Z(eff)-are achieved in this scenario. Furthermore, there are indications of significantly reduced heat load on the divertor target plates.

Long timescale density peaking has been observed in JET plasmas leading to densities exceeding the Greenwald value. These neutral beam heated discharges are characterized by type-I ELMs and good energy confinement. Central density is limited by neoclassical tearing modes or by termination of H-mode preceded by loss of sawteeth. When these limiting factors are avoided (i.e. at intermediate power level and with optimization of gas puffing) quasi-stationary high density plasmas with peaked density profile are obtained.

ELMy H-mode is one of the foreseen operational scenarios for ITER-FEAT. Good confinement and density is usually associated with Type I ELMs, which, however, will have a severe impact on the divertor target plates in ITER. At the JET-tokamak, impurities have been seeded into a variety of discharge configurations, by which the radiation level can be risen by a factor of 2. This delays the appearance of ELMs and reduces the power load onto the divertor target plates. In this paper, the influence of the impurities on the ELM behaviour and the plasma edge properties will be discussed. Several divertor diagnostics, such as electrical probes and infrared camera indicate a reduction of the heat power load at the inner divertor target tiles and a shrinking of the impact zone at the outer divertor.

Several approaches are used at JET to achieve operation at high density with good energy confinement. One of them is the injection of solid fuel pellets to realize efficient particle refuelling by deposition deep inside the plasma column. The new pellet launch system capable of launching from the torus magnetic high field side was investigated for its capability to fulfil this task in conventional ELMy H-mode discharges. Optimized pellet scenarios were developed for plasma configurations with IP = 2.5 MA, Bt = 2.4 T, averaged triangularity � δ �≈ 0.34 and mainly neutral beam heating at a level of approximately 17 MW. The accessible operational range was extended by the pellet tool with respect to gas puff refuelling. For example, H-mode conditions could be maintained at densities beyond the Greenwald level. Plasma energy confinement was observed to become density independent at high densities. When avoiding confinement deterioration due to pellet triggered MHD activity or parasitic pellet born gas in appropriate pulse schedules, enhanced particle inventory with more peaked density profiles was achieved while maintaining the plasma

A global particle balance analysis has been applied to a variety of L-mode and H-mode deuterium discharges of the C4 campaign of JET, performed at a lower wall temperature, in different magnetic configurations and with various divertor gas puffing location. Wall retention and divertor particle exhaust are discussed as a function of the plasma configuration, the wall temperature and the gas puffing location. The effect on ELMs frequency is also mentioned. A simple empirical law linking the divertor pressure and the Da signal integrated on the divertor is derived, which allows one to estimate the inner and outer contribution to pumping.

Pellet injection was investigated for its fuelling capability to high densities in ELMy H mode discharges at JET. Applying the high field side launch system, optimized refuelling scenarios were developed on the basis of conventional discharge configurations withIp= 2.5 MA,Bt= 2.4 T, averaged triangularity ⟨δ⟩≈0.34 and mainly neutral beam heating at a level of approximately 17 MW. The accessible operational range was extended with respect to gas puff refuelling by the use of pellet injection. For example, H mode conditions could be maintained at densities beyond the Greenwald level. Plasma energy confinement was observed to become density independent at high densities. Deep pellet particle deposition made possible the uncoupling of edge and core density, allowing more peaked density profiles. When confinement deterioration due to pellet triggered MHD activity or parasitic pellet borne gas was avoided in appropriate pulse schedules, an enhanced particle inventory was achieved while maintaining the plasma pressure profile. In a technical assessment it was found that there is still room for further enhancement of the injection scenario by improved adaptation to high density plasma operation.

The field of biochemistry is currently faced with the enormous challenge of assigning functional significance to more than thirty thousand predicted protein products encoded by the human genome. In order to accomplish this daunting task, methods will be required that facilitate the global analysis of proteins in complex biological systems. Recently, methods have been described for simultaneously monitoring the activity of multiple enzymes in crude proteomes based on their reactivity with tagged chemical probes. These activity based probes (ABPs) have used either radiochemical or biotin/avidin-based detection methods to allow consolidated visualization of numerous enzyme activities. Here we report the synthesis and evaluation of fluorescent activity based probes for the serine hydrolase super-family of enzymes. The fluorescent methods detailed herein provide superior throughput, sensitivity, and quantitative accuracy when compared to previously described ABPs, and provide a straight-forward platform for high-throughput proteome analysis.

A photolabile linker based on a thiohydroxamic acid has been shown to be an efficient ‘traceless’ linker, revealing an aliphatic CH bond on photolysis at 350 nm. Methods for the synthesis, loading and photolytic cleavage of the linker are described.

Cyclopent-2-enones bearing a plane-nonsymmetric oxygen function on C-4 reacted efficiently with anions derived from aromatic ester dithioacetals to provide annulated products in a highly diastereoselective fashion. Whereas the anion of a dimethoxy aromatic ester dithiolane more rapidly reacted by an alternative intramolecular pathway, the anion of the corresponding aromatic ester dithiane was suitable for the intermolecular cyclization.

Estimations of the ITER first wall (FW) life time, previously made by the 3D Monte- Carlo ERO code, depend strongly on the assumptions of the physical sputtering yield for beryllium (Be). It is of importance to validate the respective model and data at existing devices including the JET ITER- Like Wall (ILW) as most ITER- relevant experiment. Applying the same sputtering input data in ERO as before in the ITER- predictions, the ERO simulations for the Be light intensity (up- to- date atomic data is used) near the solid Be limiter in the JET- ILW case reveal a factor 2 overestimation of the assumed yield even if the low estimate assuming 50% D surface content is used. This result indicates the preference of this assumption for plasma- wetted areas. It points to a possible (after eliminating of uncertainties) necessity to correct (reduce) the respective estimates for the Be sputtering yield and accordingly, re- visit the ITER FW life time predictions.

An overview of the recent results of Lower Hybrid (LH) experiments at JET with the ITER-like wall (ILW) is presented. Topics relevant to LH wave coupling are addressed as well as issues related to ILW and LH system protections. LH wave coupling was studied in conditions determined by ILW recycling and operational constraints. It was concluded that LH wave coupling was not significantly affected and the pre-ILW performance could be recovered after optimising the launcher position and local gas puffing. SOL density measurements were performed using a Li-beam diagnostic. Dependencies on the D2 injection rate from the dedicated gas valve, the LH power and the LH launcher position were analysed. SOL density modifications due to LH were modelled by the EDGE2D code assuming SOL heating by collisional dissipation of the LH wave and/or possible E¥B drifts in the SOL. The simulations matched reasonably well the measured SOL profiles. Observations of arcs and hotspots with visible and IR cameras viewing the LH launcher are presented.

During the first year of the JET-ILW operation, a substantial effort was devoted to the L-mode domain characterization with the newly installed ITER-Like Wall (ILW), consisting of a W divertor and a Be main chamber. Main experimental results were reported in [1] [2]. This paper presents the results of modelling studies, carried out with EDGE2D/EIRENE code, of a couple of two similar aforementioned discharges to investigate on the the effects of divertor plasma configuration and proximity of the low-field side (LFS) strike-point with respect to the LFS pumping plenum when comparing the simulation results with the experimental data of two different divertor configurations at same upstream density. The analysis focuses on the observed differences in the sub-divertor neutral pressures in relation to the deuterium ion fluxes to the divertor plates.

An all-metal ITER-Like Wall (JET-ILW), consisting of beryllium in the main chamber and tungsten surfaces in the divertor, has now been installed in JET to pursue low retention of fuel species and to explore the impact on next-step-relevant plasmas. Its implementation has offered a unique opportunity to compare behaviour with that in the previous all-Carbon lining (JET-C), notably for high-triangularity Type I H-modes with impurity seeding. This technique is recognised to be necessary for power handling both in ITER and in JET at full performance. Contrasting results are reported for closely-matched deuterium-fuelling plus nitrogen-seeding scans in each JET environment. Attention is focused upon neutral-beam-heated plasmas with total input power 15­17MW at 2.65T, 2.5MA, q95 3.5 , average triangularity d 0.4 , elongation k 1.7 and gas inputs spanning ranges 0.75 FD 3.3 , 0 FD 4.7 (1022 electrons / s assuming full ionisation). JET-C cases also included 1­2MW of central ion-cyclotron-resonance-frequency heating, so far absent from JET-ILW pulses, with possible consequences for respective core sawtooth and impurity-concentration results.

In this paper, results from the array of fixed Langmuir probes in the JET Mark I divertor are presented. During low density discharges there is good agreement between single and triple probes. At higher density, near the onset of divertor detachment, very low values of the electron to ion saturation current (even < 1) are observed which results in an overestimation of the electron temperature, particularly by the triple probe. Alternative methods of probe interpretation are applied and comparisons carried out with independent measurements. The consistency of probe measurements during H-mode discharges are also briefly discussed.