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Settlement of investment disputes under the Energy Charter Treaty
\"The Energy Charter Treaty has come of age, with almost 50 States parties and a small but growing body of arbitral case law. In this new study of the Treaty's investment protection provisions, Thomas Roe and Matthew Happold set out to identify and explain the Treaty's principal provisions and to suggest answers to some of the difficult problems thrown up by its drafting. They discuss in detail questions such as the standards of protection granted by the Treaty and the international responsibility of States for breaches of the Treaty, the various procedures available for the vindication of rights under the Treaty and the conditions to be satisfied before a claimant's complaint may be considered on the merits. Specific issues addressed include the impact of EU law on claims under the Treaty and the Treaty's provisions concerning taxation\"-- Provided by publisher.
Book
Hyper‐resolution in X‐ray emission spectroscopy: integrating extended‐range high energy resolution fluorescence detection and multiple‐crystal spectrometry with advanced binary data splicing
This study of manganese (Mn, Z = 25) introduces a novel combination of extended‐range high energy resolution fluorescence detection (XR‐HERFD), multiple‐crystal spectrometers and advanced binary data splicing techniques to address challenges in X‐ray emission spectroscopy. XR‐HERFD enhances spectral precision by utilizing high‐resolution crystal analysers and optimized detector configurations. The systematic application of these methods using multiple Bragg crystal analysers at Diamond Light Source has led to substantial improvements in data quality. Simultaneously, advanced binary data splicing integrates multiple datasets to correct distortions and improve resolution, resulting in sharper spectral features. Our results show a significant increase in peak counts and a notable reduction in full width at half‐maximum (FWHM), with peak amplitudes increasing by 83% and resolution improving by 46%. These developments provide greater detail for X‐ray absorption or emission spectra, offering valuable insights into complex materials, and permitting advances and breakthroughs in atomic relativistic quantum mechanics, chemical sensitivity of atomic transitions and modelling of solid‐state effects. A robust integration is introduced of the extended‐range high energy resolution fluorescence detection technique, multiple‐crystal spectrometers and binary data splicing techniques for the further refinement of spectra in X‐ray emission spectroscopy, revealing deeper insights into material properties and atomic transitions.
Journal Article
Experimental evaluation of the GE NM/CT 870 CZT clinical SPECT system equipped with WEHR and MEHRS collimator
Purpose A high‐energy‐resolution whole‐body SPECT‐CT device (NM/CT 870 CZT; C‐SPECT) equipped with a CZT detector has been developed and is being used clinically. A MEHRS collimator has also been developed recently, with an expected improvement in imaging accuracy using medium‐energy radionuclides. The objective of this study was to compare and analyze the accuracies of the following devices: a WEHR collimator and the MEHRS collimator installed on a C‐SPECT, and a NaI scintillation detector‐equipped Anger‐type SPECT (A‐SPECT) scanner, with a LEHR and LMEGP. Methods A line phantom was used to measure the energy resolutions including collimator characteristics in the planar acquisition of each device using 99mTc and 123I. We also measured the system's sensitivity and high‐contrast resolution using a lead bar phantom. We evaluated SPECT spatial resolution, high‐contrast resolution, radioactivity concentration linearity, and homogeneity, using a basic performance evaluation phantom. In addition, the effect of scatter correction was evaluated by varying the sub window (SW) employed for scattering correction. Results The energy resolution with 99mTc was 5.6% in C‐SPECT with WEHR and 9.9% in A‐SPECT with LEHR. Using 123I, the results were 9.1% in C‐SPECT with WEHR, 5.5% in C‐SPECT with MEHRS, and 10.4% in A‐SPECT with LMEGP. The planar spatial resolution was similar under all conditions, but C‐SPECT performed better in SPECT acquisition. High‐contrast resolution was improved in C‐SPECT under planar condition and SPECT. The sensitivity and homogeneity were improved by setting the SW for scattering correction to 3% of the main peak in C‐SPECT. Conclusion C‐SPECT demonstrates excellent energy resolution and improved high‐contrast resolution for each radionuclide. In addition, when using 123I, careful attention should be paid to SW for scatter correction. By setting the appropriate SW, C‐SPECT with MEHRS has an excellent scattered ray removal effect, and highly homogenous imaging is possible while maintaining the high‐contrast resolution.
Journal Article
Enhancing the efficiency of a wavelength-dispersive spectrometer based on a slitless design using a single-bounce monocapillary
This paper introduces a novel slit-less wavelength-dispersive spectrometer design that incorporates a single-bounce monocapillary with the goal of positioning the sample directly on the Rowland circle, thereby eliminating the need for a traditional entrance slit. This configuration enhances photon throughput while preserving energy resolution, demonstrated in comparative measurements on boron nitride and different lithium nickel manganese cobalt oxide cathodes. A common alternative to an entrance slit for limiting the source size on the Rowland circle is a customized design of the beamline involving a focusing optics unit consisting of two Kirkpatrick–Baez mirrors close to the end station. The new slit-less design does not rely on specialized beamlines and can be considered, thanks to the increased efficiency, for spectrometers using laboratory based sources equipped with equivalent optics. The comparative measurements found that the resolving power achieved was E /Δ E = 1085 at 401.5 eV incident energy, and the enhancement in detection efficiency was a factor of 3.7 due to more effective utilization of the X-ray beam.
Journal Article
Multicolor single‐analyzer high‐energy‐resolution XES spectrometer for simultaneous examination of different elements
The present work demonstrates the performance of a von Hámos high‐energy‐resolution X‐ray spectrometer based on a non‐conventional conical Si single‐crystal analyzer. The analyzer is tested with different primary and secondary X‐ray sources as well as a hard X‐ray sensitive CCD camera. The spectrometer setup is also characterized with ray‐tracing simulations. Both experimental and simulated results affirm that the conical spectrometer can efficiently detect and resolve the two pairs of two elements (Ni and Cu) Kα X‐ray emission spectroscopy (XES) peaks simultaneously, requiring a less than 2 cm‐wide array on a single position‐sensitive detector. The possible applications of this simple yet broad‐energy‐spectrum crystal spectrometer range from quickly adapting it as another probe for complex experiments at synchrotron beamlines to analyzing X‐ray emission from plasma generated by ultrashort laser pulses at modern laser facilities. This paper proves the feasibility and demonstrates the performance of a novel conical single‐crystal analyzer in a von Hámos geometry to follow two sets of Kα hard X‐ray emission peaks simultaneously, which can be used as an additional feature at synchrotron beamlines but also with laboratory setups or plasma sources. The conical‐analyzer‐based spectrometer is studied both experimentally as well as with ray‐tracing simulations to provide a broad overview and understanding.
Journal Article
X‐Ray Absorption Spectroscopy Probing of Gold Electro‐Oxidation Reveals Intermediate Surficial Au(I)
While Au electro‐oxidation in acidic aqueous media on a phenomenological level proceeds directly from Au(0) to Au(III), it has previously been suggested that Au(I) states are intermediate species of the oxidation mechanism. Here, additional evidence for the transient Au(I) is provided by the probing the electro‐oxidation of Au electrode operando in a pH = 3 perchloric acid (HClO4) electrolyte by high‐energy‐resolution fluorescence‐detected X‐ray absorption near‐edge structure (HERFD–XANES) at potentials up to 1.8 V versus the reversible hydrogen electrode (RHE). The perchlorate ions (ClO4−) in the electrolyte are used as sacrificial oxidizing agents. The reduced perchlorate compounds in turn produce chloride ions, which react with Au ions to form Au–Cl compounds. The operando HERFD–XANES detects and identifies the chlorinated compounds as surficial Au(I), present during the early stages of Au oxidation. It is further inferred that Au(I) is accessed by the electrolyte. These observations are consistent with the previously hypothesized route for Au electro‐oxidation involving charge transfer after a dipole‐induced place‐exchange step. Formation of surficial Au(I)Cl during electro‐oxidation reveals that Au(+I) is present as an intermediate during oxidation toward Au(+III) oxides. The Au‐Cl deposition is observed operando by high‐energy‐resolution fluorescence‐detected near‐edge X‐ray absorption fine structure. These observations add to the evidence for step‐wise charge transfer in Au electro‐oxidation and imply that the charge transfer step occurs after a dipole‐induced place exchange step.
Journal Article
On space charge effects in laboratory-based photoemission electron microscopy using compact gas discharge extreme ultraviolet sources
The analysis of electronic and structural properties of surfaces has been greatly advanced by photoemission electron microscopy and spectroscopy techniques. To further improve lateral and energy resolution of the instruments, it is necessary to optimize parameters of the radiation sources employed for photoemission studies (e.g. photon flux, pulse duration, spot size etc). We studied space charge effects observed in an energy-filtering photoemission electron microscope operated with a compact laboratory-scale gas-discharge extreme ultraviolet light source. In this system, we found limits of spatial- and energy-resolution controlled by the source radiation parameters. The pulse repetition rate can be varied in the kHz range and the duration of the EUV emission was measured to be several tens of nanoseconds long, and thereby very different from the standard synchrotron sources typically used for similar experiments. The spatial resolution could be improved by a factor of 5, but only on the expense of the photon density per pulse, which had to be decreased by a factor of 17 in order to reduce the image blur due to space charge effects. Furthermore, we found broadening of the x-ray photoelectron spectroscopy peaks for high photon fluxes. We have also performed a n-body Monte Carlo simulation to evaluate the difference between core-level photoelectrons and secondary electrons with respect to space charge.
Journal Article
Actinide Nanoparticles: Revising Early Developments and Recent Insights from High‐Energy‐Resolution Fluorescence‐Detected X‐Ray Absorption Near Edge Structure and Synchrotron Techniques
Actinide nanoparticles (NPs) are widely recognized for their role as a potentially highly mobile form of radioactive contaminants in the environment. In recent years, research has increasingly focused on elucidating their formation mechanisms, atomic structure, and physicochemical properties. The application of synchrotron radiation techniques is central to the detailed characterization of their atomic structure and oxidation state. This review retraces the evolution of actinide NPs research and highlights recent achievements enabled by high‐energy‐resolution fluorescence‐detected X‐ray absorption near edge structure, used in correlation with complementary synchrotron‐based methods. Actinide nanoparticles are relevant to nuclear waste storage, environmental safety, advanced nuclear fuel engineering, and fundamental science. Herein, this review traces the early developments of the field and the recent progress enabled by the use of high‐energy‐resolution fluorescence‐detected X‐ray absorption near edge structure in synergy with other synchrotron techniques.
Journal Article
Quantifying the Effect of Cosmic Ray Showers on the X-IFU Energy Resolution
The X-ray Integral Field Unit (X-IFU) will operate an array of more than 3000 Transition Edge Sensor pixels at 90 mK with an unprecedented energy resolution of 2.5 eV at 7 keV. In space, primary cosmic rays and secondary particles produced in the instrument structure will continuously deposit energy on the detector wafer and induce fluctuations on the pixels’ thermal bath. We have investigated through simulations of the X-IFU readout chain how these fluctuations eventually influence the energy measurement of X-ray photons. Realistic timelines of thermal bath fluctuations at different positions in the array are generated as a function of a thermal model and the expected distribution of the deposited energy of the charged particles. These are then used to model the TES response to these thermal perturbations and their influence on the onboard energy reconstruction process. Overall, we show that with adequate heatsinking, the main energy resolution degradation effect remains minimal and within the associated resolution allocation of 0.2 eV. We further study
how a dedicated triggering algorithm could be put in place to flag the rarer large thermal events.
Journal Article
Single-atom vibrational spectroscopy in the scanning transmission electron microscope
Single-atom impurities and other atomic-scale defects can notably alter the local vibrational responses of solids and, ultimately, their macroscopic properties. Using high-resolution electron energy-loss spectroscopy in the electron microscope, we show that a single substitutional silicon impurity in graphene induces a characteristic, localized modification of the vibrational response. Extensive ab initio calculations reveal that the measured spectroscopic signature arises from defect-induced pseudo-localized phonon modes—that is, resonant states resulting from the hybridization of the defect modes and the bulk continuum—with energies that can be directly matched to the experiments. This finding realizes the promise of vibrational spectroscopy in the electron microscope with single-atom sensitivity and has broad implications across the fields of physics, chemistry, and materials science.
Journal Article