Hydropower plants operating in fragile mountainous regions face severe sediment erosion of hydraulic turbines, resulting in decreased efficiency, frequent power interruptions, and downtime for maintenance. The sediment size and shape are detrimental to the hydraulic turbines and influence sediment erosion. Sediment management is a crucial aspect of tackling sediment erosion in hydraulic turbines. The traditional method of measuring particle size and shape is time-consuming, labour-intensive, and usually requires statistical analysis. The present study applies the recent technique of dynamic imaging analysis to determine the particle size distribution and shape of sediment. Five different silt-sand mixtures have been used to check the ability of dynamic imaging analysis. Further, the repeatability and reliability of the results were checked by carrying out five repeated measurements of each sample under the same condition in a short period of time. This study will help the researchers and sedimentologists to adopt the dynamic imaging analysis technique for measuring particle size and shape and help the instrument developer in designing a better future version of the instrument.

Several countries use a single, defined willingness to pay (WTP) threshold for formulary decision making. This value may not truly reflect the perceived risk of individual diseases in terms of mortality, morbidity, and epidemiology. Study objectives were to systematically review the existing literature for WTP thresholds and evaluate their association with perceived risk for most common diseases from the healthcare researchers' perspective. Articles were systematically retrieved from PubMed from 2013 to 2018. The WTP thresholds of healthcare interventions for each disease state (nephropathy, depression, hypertension, arthritis, asthma, psoriasis, pancreatic-cancer, hepatitis-C, AF, pain, stroke, cardiovascular, HIV, T2DM, COPD, and NSCLC) were retrieved from individual article. The WTP thresholds reported in different currency denominations were standardized to US dollars using the 2017 IRS average exchange rates. The variations in the published WTP thresholds were compared and presented using box-plots and scatter-plots with Microsoft Excel 2016 and SAS 9.4. Of 736 articles retrieved from PubMed, 330 were included for WTP thresholds assessment. A substantial variability was observed among the published WTP thresholds. Diseases with high mortality, recurrences, and having high impact on patients' quality of life tend to have higher WTP thresholds. WTP thresholds ranged from $2,154 to as high as $200,000 per QALY for debilitating diseases such as pancreatic-cancer, NSCLC, asthma, and pain. The median WTP thresholds for psoriasis and AF were above the generally acceptable WTP threshold of $50,000/QALY. Whereas, for nephropathy, arthritis, and NSCLC, the median WTP thresholds were $50,000/QALY each. Overall, the range of median WTP thresholds for all diseases ranged from $27,653 to $65,005/QALY. Flexible thresholds for disease types may be proposed to reflect the disease risk and opportunity cost of treatment. Further studies should be conducted to evaluate WTP thresholds for additional disease states from diverse stakeholders' perspective.

D. Schury1, A. Kumar1, A. Méry2, J.M. Ramillon2, L. Adoui2, J.-Y. Chesnel2, A. Lévy1, S. Macé1, C. Prigent1, J. Rangama2, P. Rousseau2, S. Steydli1, M. Trassinelli1, D. Vernhet1, A. Gumberidze3, Th. Stöhlker3,4,5, A. Bräuning-Demian3, C. Hahn4, U. Spillmann3 and E. Lamour1 1. Institut des Nanosciences de Paris, UMR CNRS 7588, Sorbonne Université, 4 Place Jussieu, 75005 Paris, France 2. CIMAP,CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, Boulevard Henri Becquerel, 14070 Caen, France 3. GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, 64291 Darmstadt, Germany 4. Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany 5. Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany

Spectroscopic investigations of highly charged ions are very important not only for atomic physics but also for astrophysical and laboratory fusion plasmas. For example, the atomic data of highly charged iron ions with charge state around 10 are strongly needed for the spectroscopic diagnostics of the solar corona with the recently launched satellite Hinode. For spectroscopic studies of such moderately charged ions, we have recently constructed a compact electron beam ion trap (EBIT). The electron energy range of the present EBIT is 100-1500 eV, which is rather low compared to that of ordinary EBITs, and thus enabled us to downsize it. We have also developed a dedicated slitless spectrometer consisting of a 1200 lines/mm laminar-type replica diffraction grating and a back-illuminated CCD. The cross sectional view of the EBIT and the spectrometer is shown in Fig.1. It is possible to employ a slitless type of spectrometer because an EBIT represents a line source with a width of ~0.1 mm. Typical EUV spectra of highly charged iron ions are shown in Fig.2. As shown in this example, various charge state ions can be selectively produced with a narrow charge state distribution by adjusting the electron beam energy. Thus the charge state of unknown lines can be identified through such energy dependence measurements. On the other hand, the electron density dependence of line ratios, which are very important for plasma diagnostics, can be studied by changing the electron beam current at a fixed energy. First results of the new EBIT are presented.

In heliumlike ions, the (1s2s) S0 state can decay to the ground state (1s ) S0 via a two-photon (2E1) transition. The energy distribution of the two-photon emission forms a continuous spectrum which has its maximum intensity at half of the transition energy and gradually falls to zero at both endpoints. This continuum energy distribution is determined by the summation over all intermediate bound and continuum states of the transition probabilities. Hence, the spectral shape of the 2E1 decay is sensitive to the entire atomic structure. In heliumlike ions, the nonrelativistic calculations predict an increase in the width of the spectral distribution with atomic nuclear charge Z. Fully relativistic calculations show that at low Z the width behaves similar to the nonrelativistic calculations while at high Z the distribution narrows [1, 2]. Therefore, a measurement of the spectral distribution of the 2E1 decay along the isoelectronic sequence of heliumlike ions uniquely probes our understanding of the interplay between electron-electron correlation and relativistic effects on the structure of the simplest multi-electron atomic system.

R. Reuschl, A. Gumberidze, Th. Stöhlker, D. Banas, H. Bräuning, C. Brandau, H. F. Beyer, S. Hagmann, C. Kozhuharov, A. Kubala-Kukus, A. Kumar, A. Simon, U. Spillmann, Z. Stachura , M. Trassinelli, S. Trotsenko GSI, Darmstadt, Germany; 2 IKF, University of Frankfurt, Frankfurt, Germany; Swietokrzyska Academy, Kielce, Poland; Tata Institute of Fundamental Research, India; Jagiellonian University, Cracow, Poland; 6 INP, Cracow, Poland; École Normale Supérieure, CNRS, Univ. Pierre et Marie Curie-Paris 6, France