An overview of tritium retention in dust particles from the JET-ILW divertor

Tritium (T) retention characteristics in dust collected from the divertor in JET with ITER-like wall (JET-ILW) after the third campaign in 2015-2016 (ILW-3) have been examined in individual dust particles by combining radiography (tritium imaging plate technique) and electron probe micro-analysis. The results are summarized and compared with the data obtained after the first campaign in 2011-2012 (ILW-1). The dominant component in ILW-1 dust was carbon (C) originating from tungsten-coated carbon fibre composite (CFC) tiles in JET-ILW divertor and/or legacy of C dust after the JET operation with carbon wall. Around 85 % of the total tritium retention in ILW-1 dust was attributede to the C dust. The retention in tungsten (W) and beryllium (Be) dominated particles was 100 times smaller than the highest T retention in carbon-based particles. After ILW-3 the main component contributing to the T retention was W. The number of small W particles with T increased, in comparison to ILW-1, most probably by the exfoliation and fragmentation of W coatings on CFC tiles though T retention in individual W particles was smaller than in C particles. The detection of only very few Be-dominated dust particles found after ILW-1 and ILW-3 could imply stable Be deposits on the divertor tiles.

Radiation Imaging with Caesium Bromide Storage Phosphors

<p>This thesis is centred on the development of a new method to prepare semitransparent CsBr:Eu²⁺ imaging plates for high resolution X-ray radiography. Methods of characterising the performance of these plates, and their application to dual energy imaging and neutron imaging are discussed. The basic preparation method, based on high-pressure uniaxial compression of powder mixtures of CsBr and EuBr₂, produces imaging plates which show good transparency and resolution. These imaging plates have a conversion efficiency of 1.5 pJmR⁻¹mm⁻³ compared to 5.1 pJmR⁻¹mm⁻³ for a commercial needle imaging plate. Water is found to play a critical role in the photostimulated luminescence activation in CsBr:Eu²⁺ storage phosphors, and imaging plates subsequently hydrated at room temperature have an increased conversion efficiency of up to 11 pJmR⁻¹mm⁻³, better than the commercial material. A model has been suggested for the generation of the PSL active site in the imaging plates based on thermomechanical sintering and water-induced crystal regrowth. A precise method for determining the conversion efficiency and stimulation energy of X-ray storage phosphor materials using an integrating sphere has been developed and used to characterise the materials developed in this thesis. A novel read-out method for storage phosphor imaging plates based on flood illumination and a semi-professional digital camera has also been developed and tested. Good quality X-ray images are obtained and the method shows excellent promise as a low-cost, portable X-ray imaging system. A stratified detector using CsBr imaging plates has been developed for use in dual-energy imaging. Results suggest that it is possible to perform dual-energy imaging with this structure. CsBr:Eu²⁺ imaging plates have been produced with added neutron converters for use as thermal neutron imaging plates. An imaging plate with 5 % ¹ºB₂O₃ added as a neutron converter has a PSL output 50 % that of a commercial neutron imaging plate. Neutron imaging with these imaging plates has been successfully demonstrated.</p>

Radiation Imaging with Caesium Bromide Storage Phosphors

<p>This thesis is centred on the development of a new method to prepare semitransparent CsBr:Eu²⁺ imaging plates for high resolution X-ray radiography. Methods of characterising the performance of these plates, and their application to dual energy imaging and neutron imaging are discussed. The basic preparation method, based on high-pressure uniaxial compression of powder mixtures of CsBr and EuBr₂, produces imaging plates which show good transparency and resolution. These imaging plates have a conversion efficiency of 1.5 pJmR⁻¹mm⁻³ compared to 5.1 pJmR⁻¹mm⁻³ for a commercial needle imaging plate. Water is found to play a critical role in the photostimulated luminescence activation in CsBr:Eu²⁺ storage phosphors, and imaging plates subsequently hydrated at room temperature have an increased conversion efficiency of up to 11 pJmR⁻¹mm⁻³, better than the commercial material. A model has been suggested for the generation of the PSL active site in the imaging plates based on thermomechanical sintering and water-induced crystal regrowth. A precise method for determining the conversion efficiency and stimulation energy of X-ray storage phosphor materials using an integrating sphere has been developed and used to characterise the materials developed in this thesis. A novel read-out method for storage phosphor imaging plates based on flood illumination and a semi-professional digital camera has also been developed and tested. Good quality X-ray images are obtained and the method shows excellent promise as a low-cost, portable X-ray imaging system. A stratified detector using CsBr imaging plates has been developed for use in dual-energy imaging. Results suggest that it is possible to perform dual-energy imaging with this structure. CsBr:Eu²⁺ imaging plates have been produced with added neutron converters for use as thermal neutron imaging plates. An imaging plate with 5 % ¹ºB₂O₃ added as a neutron converter has a PSL output 50 % that of a commercial neutron imaging plate. Neutron imaging with these imaging plates has been successfully demonstrated.</p>

Light Scattering in Glass Ceramic X-ray Imaging Plates

<p>Glass ceramic materials have been suggested as a possible high resolution replacement for current commercial storage phosphor imaging plates. The low spatial frequency of the current plates is caused by strong scattering of the laser light incident on the plate during the read-out process. Glass ceramic materials show very small scattering due to their transparent nature, which should lead to a higher resolution. However, a competing argument is the small amount of scattering that does occur travels a much greater distance in the plate, limiting the resolution. The aim of this thesis was to simulate the scattering of light in imaging plates and use this to optimise the trade-off between resolution, sensitivity and transparency which is implicit in plate design. Additionally, experiments were performed to determine the resolution of glass ceramic and commercial imaging plates. Simulations show that high resolution can be achieved in both the strong and weak scattering limits, corresponding to opaque and transparent materials. Increasing the absorption of the laser light increases the resolution, as does decreasing the laser beam diameter and power. An increase in the resolution almost always comes at a cost of a decrease in the sensitivity. The resolutions of an Agfa MD30 and glass ceramic imaging plate were found to be 4:5 line pairs/mm and 6:5 - 8:0 line pairs/mm respectively for an MTF equal to 0:2.</p>

Light Scattering in Glass Ceramic X-ray Imaging Plates

<p>Glass ceramic materials have been suggested as a possible high resolution replacement for current commercial storage phosphor imaging plates. The low spatial frequency of the current plates is caused by strong scattering of the laser light incident on the plate during the read-out process. Glass ceramic materials show very small scattering due to their transparent nature, which should lead to a higher resolution. However, a competing argument is the small amount of scattering that does occur travels a much greater distance in the plate, limiting the resolution. The aim of this thesis was to simulate the scattering of light in imaging plates and use this to optimise the trade-off between resolution, sensitivity and transparency which is implicit in plate design. Additionally, experiments were performed to determine the resolution of glass ceramic and commercial imaging plates. Simulations show that high resolution can be achieved in both the strong and weak scattering limits, corresponding to opaque and transparent materials. Increasing the absorption of the laser light increases the resolution, as does decreasing the laser beam diameter and power. An increase in the resolution almost always comes at a cost of a decrease in the sensitivity. The resolutions of an Agfa MD30 and glass ceramic imaging plate were found to be 4:5 line pairs/mm and 6:5 - 8:0 line pairs/mm respectively for an MTF equal to 0:2.</p>

Penentuan Peak Kilovoltage (kVp) Pesawat Sinar-X Dengan Pemanfaatan Imaging Plate (IP) Di RSUD Dr. Moewardi

<p>Research has been carried out to determine the kVp of X-ray aircraft using an imaging plate (IP) as a measuring tool. The imaging plate functions to record images after irradiation and as a detector to capture and store X-ray energy when it penetrates an object. The purpose of this study is to use IP as a kVp measurement tool. The method used is to create a characteristic curve of the relationship between the ratio of Region of Interest (ROI) of two aluminum filters to rated voltage (kVp). From the research obtained the equation y = 2816.61 x2 – 4532.19 x + 1878.65 with R2 = 0.988. The kVp test was carried out using a fluoroscopic X-ray model SM-20HFH. The test results obtained that the measured kVp value at a voltage of 70 kV was 66.21 kV and an error value of 5.41%. While the measured kVp value at 55 kV is 58.95 kV with an error value of -7.18%. These results indicate that IP can be used to measure kVp with an error below the allowable tolerance, namely the max error ≤ of 10%.</p>

5-(Indol-2-yl)pyrazolo[3,4-b]pyridines as a New Family of TASK-3 Channel Blockers: A Pharmacophore-Based Regioselective Synthesis

TASK channels belong to the two-pore-domain potassium (K2P) channels subfamily. These channels modulate cellular excitability, input resistance, and response to synaptic stimulation. TASK-channel inhibition led to membrane depolarization. TASK-3 is expressed in different cancer cell types and neurons. Thus, the discovery of novel TASK-3 inhibitors makes these bioactive compounds very appealing to explore new cancer and neurological therapies. TASK-3 channel blockers are very limited to date, and only a few heterofused compounds have been reported in the literature. In this article, we combined a pharmacophore hypothesis with molecular docking to address for the first time the rational design, synthesis, and evaluation of 5-(indol-2-yl)pyrazolo[3,4-b]pyridines as a novel family of human TASK-3 channel blockers. Representative compounds of the synthesized library were assessed against TASK-3 using Fluorometric imaging plate reader—Membrane Potential assay (FMP). Inhibitory properties were validated using two-electrode voltage-clamp (TEVC) methods. We identified one active hit compound (MM-3b) with our systematic pipeline, exhibiting an IC50 ≈ 30 μM. Molecular docking models suggest that compound MM-3b binds to TASK-3 at the bottom of the selectivity filter in the central cavity, similar to other described TASK-3 blockers such as A1899 and PK-THPP. Our in silico and experimental studies provide a new tool to predict and design novel TASK-3 channel blockers.

High-temperature diffraction experiments and phase diagram of ZrO2 and ZrSiO4

High-temperature X-ray diffraction (XRD) experiments up to T = 2710 °C have been performed on ZrSiO4 and ZrO2 powders, using the container-less levitation technique. A two-dimensional imaging plate (IP) detector was used for short-time observation. The diffraction data in a wide area was projected in one dimension. The unit cell parameters, thermal expansions, and c/a ratios for ZrSiO4 (space group I41/amd and Z = 4), tetragonal ZrO2 (space group P42/nmc and Z = 2) and cubic ZrO2 (space group F m 3 ‾ m $Fm3&#x203e;{}m$ and Z = 4) were measured to understand the high-temperature behaviors. The transition temperature between tetragonal and cubic ZrO2 was specified to be between 2430 and 2540 °C. The pre-transitional behavior was observed around 2200 °C. As no clear change in unit cell volume is evident, the phase boundary between the tetragonal and the cubic phase has been shown to be a positive slope. The ZrO2 and ZrO2–SiO2 phase diagrams are proposed based on the chemical composition and the crystal structure.

Selective activation of TRPA1 ion channel by skin sensitizer nitrobenzene DNFB

BACKGROUND AND PURPOSE: Chemical 2, 4-dinitrofluorobenzene (DNFB), commonly called as Sanger’s reagent, is well known as skin sensitizer to cause dermatitis. However, how the DNFB causes skin inflammation remains unknown. In this study we aimed at identifying the molecular target that DNFB acts on. EXPERIMENTAL APPROACH: We used a fluorescent calcium imaging plate reader as an initial screening assay and patch-clamp recordings for validation. Molecular docking in combination with site-directed mutagenesis was carried out to investigate DNFB binding sites in TRPA1 ion channel. KEY RESULTS: We found the chemical DNFB that selectively activates TRPA1 channel with EC50 of 2.36 ± 0.26 µM. Single-channel recording reveals that DNFB increases the channel open probability and acts on three residues C621, Y658 and E625 critical for DNFB-mediated TRPA1 activation. CONCLUSION AND IMPLICATIONS: Our findings not only explain a molecular mechanism underlying the dermatitis and pruritus caused by chemical DNFB, but also provides a molecular tool that is 7.5-time more potent than current AITC molecule and can be used for elucidating TRPA1 channel pharmacology and pathology.