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1. Unravelling the complex speciation of halozincate ionic liquids using X-ray spectroscopies and calculations.

Author

Seymour, J. M., Gousseva, E., Towers Tompkins, F. K., Parker, L. G., Alblewi, N. O., Clarke, C. J., Hayama, S., Palgrave, R. G., Bennett, R. A., Matthews, R. P., and Lovelock, K. R. J.

Abstract

Using a combination of liquid-phase X-ray spectroscopy experiments and small-scale calculations we have gained new insights into the speciation of halozincate anions in ionic liquids (ILs). Both core and valence X-ray photoelectron spectroscopy (XPS) experiments were performed directly on the liquid-phase ILs, supplemented by Zn 1s X-ray absorption near edge structure (XANES) spectroscopy. Density functional theory (DFT) calculations were carried out on both 1− and 2− halozincate anions, in both a generalised solvation model SMD (Solvation Model based on Density) and the gas phase, to give XP spectra and total energy differences; time-dependent DFT was used to calculate XANES spectra. Speciation judgements were made using a combination of the shape and width of the experimental spectra, and visual matches to the calculated spectra. For 2− halozincate anions, excellent matches were found between the experimental and calculated XP spectra, clearly showing that only 2− halozincate anions were present at all zinc halide mole fractions, x, studied. At specific values of x (0.33, 0.50, 0.60) only one halozincate anion was present; equilibria of different halozincate anions at those values of x were not observed. All findings show that chlorozincate anion and bromozincate anion speciation matched at the same x. Based on the results, predictions are made of the halozincate anion speciation for all values of x up to 0.67. Caution is advised when using differences in calculated total energies obtained from DFT to judge halozincate anion speciation, even when the SMD was employed, as predictions based on total energy differences did not always match the findings from the experimental and calculated spectra. Our findings clearly establish that the combination of high-quality experimental data from multiple spectroscopies and a wide range of calculated structures are essential to have high confidence in halozincate anion speciation identification. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Redox state and photoreduction control using X-ray spectroelectrochemical techniques: advances in design and fabrication through additive engineering

Author

Best, SP, Streltsov, VA, Chantler, CT, Li, W, Ash, PA, Hayama, S, Diaz-Moreno, S, Best, SP, Streltsov, VA, Chantler, CT, Li, W, Ash, PA, Hayama, S, and Diaz-Moreno, S

Abstract

The design and performance of an electrochemical cell and solution flow system optimized for the collection of X-ray absorption spectra from solutions of species sensitive to photodamage is described. A combination of 3D CAD and 3D printing techniques facilitates highly optimized design with low unit cost and short production time. Precise control of the solution flow is critical to both minimizing the volume of solution needed and minimizing the photodamage that occurs during data acquisition. The details of an integrated four-syringe stepper-motor-driven pump and associated software are described. It is shown that combined electrochemical and flow control can allow repeated measurement of a defined volume of solution, 100 µl, of samples sensitive to photoreduction without significant change to the X-ray absorption near-edge structure and is demonstrated by measurements of copper(II) complexes. The flow in situ electrochemical cell allows the collection of high-quality X-ray spectral measurements both in the near-edge region and over an extended energy region as is needed for structural analysis from solution samples. This approach provides control over photodamage at a level at least comparable with that achieved using cryogenic techniques and at the same time eliminates problems associated with interference due to Bragg peaks.

Published
2021

10. Radiation-hard semiconductor detectors for SuperLHC

Author

Bruzzi, M., Adey, J., Al-Ajili, A., Alexandrov, P., Alfieri, G., Allport, P.P., Andreazza, A., Artuso, M., Assouak, S., Avset, B.S., Barabash, L., Baranova, E., Barcz, A., Basile, A., Bates, R., Belova, N., Biagi, S.F., Bilei, G.M., Bisello, D., Blue, A., Blumenau, A., Boisvert, V., Bolla, G., Bondarenko, G., Borchi, E., Borrello, L., Bortoletto, D., Boscardin, M., Bosisio, L., V. Bowcock, T.J., Brodbeck, T.J., Broz, J., Brukhanov, A., Brzozowski, A., Buda, M., Buhmann, P., Buttar, C., Campabadal, F., Campbell, D., Candelori, A., Casse, G., Cavallini, A., Chilingarov, A., Chren, D., Cindro, V., Citterio, M., Collins, P., Coluccia, R., Contarato, D., Coutinho, J., Creanza, D., Cunningham, W., Cvetkov, V., Dalla Betta, G.-F., Davies, G., Dawson, I., de Boer, W., De Palma, M., Demina, R., Dervan, P., Dierlamm, A., Dittongo, S., Dobrzanski, L., Dolezal, Z., Dolgolenko, A., Eberlein, T., Eremin, V., Fall, C., Fasolo, F., Ferbel, T., Fizzotti, F., Fleta, C., Focardi, E., Forton, E., Franchenko, S., Fretwurst, E., Gamaz, F., Garcia, C., Garcia-Navarro, J.E., Gaubas, E., Genest, M.-H., Gill, K.A., Giolo, K., Glaser, M., Goessling, C., Golovine, V., González Sevilla, S., Gorelov, I., Goss, J., Gouldwell, A., Grégoire, G., Gregori, P., Grigoriev, E., Grigson, C., Grillo, A., Groza, A., Guskov, J., Haddad, L., Härkönen, J., Harding, R., Hauler, F., Hayama, S., Hoeferkamp, M., Hönniger, F., Horazdovsky, T., Horisberger, R., Horn, M., Houdayer, A., Hourahine, B., Hruban, A., Hughes, G., Ilyashenko, I., Irmscher, K., Ivanov, A., Jarasiunas, K., Jin, T., Jones, B.K., Jones, R., Joram, C., Jungermann, L., Kalinina, E., Kaminski, P., Karpenko, A., Karpov, A., Kazlauskiene, V., Kazukauskas, V., Khivrich, V., Khomenkov, V., Kierstead, J., Klaiber-Lodewigs, J., Kleverman, M., Klingenberg, R., Kodys, P., Kohout, Z., Korjenevski, S., Kowalik, A., Kozlowski, R., Kozodaev, M., Kramberger, G., Krasel, O., Kuznetsov, A., Kwan, S., Lagomarsino, S., Lari, T., Lassila-Perini, K., Lastovetsky, V., Latino, G., Latushkin, S., Lazanu, S., Lazanu, I., Lebel, C., Leinonen, K., Leroy, C., Li, Z., Lindström, G., Lindstrom, L., Linhart, V., Litovchenko, A., Litovchenko, P., Litvinov, V., Lo Giudice, A., Lozano, M., Luczynski, Z., Luukka, P., Macchiolo, A., Mainwood, A., Makarenko, L.F., Mandić, I., Manfredotti, C., Marti i Garcia, S., Marunko, S., Mathieson, K., Mozzanti, A., Melone, J., Menichelli, D., Meroni, C., Messineo, A., Miglio, S., Mikuž, M., Miyamoto, J., Moll, M., Monakhov, E., Moscatelli, F., Murin, L., Nava, F., Naoumov, D., Nossarzewska-Orlowska, E., Nummela, S., Nysten, J., Olivero, P., Oshea, V., Palviainen, T., Paolini, C., Parkes, C., Passeri, D., Pein, U., Pellegrini, G., Perera, L., Petasecca, M., Piatkowski, B., Piemonte, C., Pignatel, G.U., Pinho, N., Pintilie, I., Pintilie, L., Polivtsev, L., Polozov, P., Popa, A.I., Popule, J., Pospisil, S., Pucker, G., Radicci, V., Rafí, J.M., Ragusa, F., Rahman, M., Rando, R., Roeder, R., Rohe, T., Ronchin, S., Rott, C., Roy, P., Roy, A., Ruzin, A., Ryazanov, A., Sadrozinski, H.F.W., Sakalauskas, S., Scaringella, M., Schiavulli, L., Schnetzer, S., Schumm, B., Sciortino, S., Scorzoni, A., Segneri, G., Seidel, S., Seiden, A., Sellberg, G., Sellin, P., Sentenac, D., Shipsey, I., Sicho, P., Sloan, T., Solar, M., Son, S., Sopko, B., Spencer, N., Stahl, J., Stavitski, I., Stolze, D., Stone, R., Storasta, J., Strokan, N., Strupinski, W., Sudzius, M., Surma, B., Suuronen, J., Suvorov, A., Svensson, B.G., Tipton, P., Tomasek, M., Troncon, C., Tsvetkov, A., Tuominen, E., Tuovinen, E., Tuuva, T., Tylchin, M., Uebersee, H., Uher, J., Ullán, M., Vaitkus, J.V., Vanni, P., Velthuis, J., Verzellesi, G., Verbitskaya, E., Vrba, V., Wagner, G., Wilhelm, I., Worm, S., Wright, V., Wunstorf, R., Zabierowski, P., Zaluzhny, A., Zavrtanik, M., Zen, M., Zhukov, V., and Zorzi, N.

Published
2005
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11. Delayed gastric emptying after pancreatoduodenectomy: comparison between two different pancreatic reconstruction techniques

Author

Hirano S, Hayama S, and Senmaru N

Subjects
medicine.medical_specialty, Text mining, Gastric emptying, business.industry, Internal medicine, fungi, Medicine, business, Gastroenterology
Abstract

Background The association between delayed gastric emptying (DGE) after pancreatoduodenectomy (PD) and pancreatic reconstruction technique remain unclear. The aim of this study is to investigate whether the occurrence of DGE differs between pancreaticojejunostomy (PJ) and pancreaticogastrostomy (PG). Methods A total of 83 patients who underwent subtotal stomach-preserving pancreatoduodenectomy was retrospectively analyzed, and the factors associated with clinically relevant DGE were explored. These patients were divided into a PG group and a PJ group according to the pancreatic reconstruction. DGE occurrence and its association with intra-abdominal complications was compared between the two types of pancreatic reconstruction. Results The overall incidence of DGE was 27.7%. Intra-abdominal complications including pancreatic fistula were strongly associated with DGE. As to the pancreatic reconstruction, DGE developed more frequently in the PG than in the PJ. In addition, DGE with intra-abdominal complications tended to be more frequent in PG, despite the fact that intra-abdominal complications occurred at a similar frequency in both groups. Conclusions Intra-abdominal complications were strongly associated with DGE. As to the pancreatic reconstruction, DGE developed more frequently in the PG than in the PJ. We speculate that intra-abdominal complications affected patients with PG more and resulted in frequent occurrence of DGE.

Published
2019
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18. First Results Using the New DLS Xspress4 Digital Pulse Processor with Monolithic Segmented HPGe Detectors on XAS Beamlines.

Author

Dennis, G., Helsby, W., Omar, D., Horswell, I., Tartoni, N., Hayama, S., Mikulska, I., and Diaz-Moreno, S.

Subjects
X-ray absorption spectra, FLUORESCENCE, PIXELS, IMAGE converters, LIGHT sources
Abstract

Diamond Light Source (DLS) I20-Scanning is a high flux X-ray Absorption Spectroscopy (XAS) beamline optimized for challenging samples, operating between 4keV and 20keV. The principal detector used for collecting XAS in fluorescence mode is a Canberra 64-pixel Monolithic Segmented Hyper Pure Germanium Detector (HPGe) historically partnered with the STFC Xspress2 Digital Pulse Processor (DPP). Prior signal analysis had shown that key parameters such as Energy Resolution and Peak-to-Background ratio are compromised by pixel-to-pixel crosstalk within the detector, especially at higher count rates (>250kcps per pixel). The DLS Detector Group have developed the new Xspress4 DPP to address such issues. This results in typically a factor 3-7 increase in detector system count rate for the same Energy Resolution and Peak-to-Background ratio compared to the previous state-of-the-art DPP. An overview of the complete detector system is given and recent results obtained during the commissioning on the beamline are shown. Further, comparative results from challenging experiments are also shown, demonstrating the improved performance attainable at the previous high count rate by partnering legacy HPGe Detectors with the latest DPP technology. [ABSTRACT FROM AUTHOR]

Published
2018
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19. X-ray diffraction studies of solutions of lithium in ammonia: The structure of the metal–nonmetal transition.

Author

Hayama, S., Skipper, N. T., Wasse, J. C., and Thompson, H.

Subjects
*LITHIUM, *AMMONIA, *NEAREST neighbor analysis (Statistics)
Abstract

The structure of solutions of lithium in ammonia has been studied at 0, 2, 8, and 22 mol % metal (MPM) and 200 K by wide-angle x-ray diffraction. The principal diffraction peak shifts from 2.14(2) Å-1 at 0 MPM to 1.93(3) Å-1 at 22 MPM, reflecting the 30% decrease in overall density as the solution expands to accommodate the excess electrons. We find that the solvent is significantly perturbed over both the short- and intermediate-length scales. The nearest neighbor (N–N) coordination number decreases from 11.8(10) at 0 MPM to 7.6(10) at 22 MPM. In addition, electrostriction around the fourfold coordinated lithium ions causes N–N correlations to become progressively shorter as concentration is increased. At 22 MPM a strong diffraction prepeak is located at 1.05(3) Å-1. Upon dilution to 2 MPM, our experiments find that this feature shifts to 1.29(5) Å-1. We conclude that the prepeak observed in our experiments is a signature of polaronic solvent cavities of approximate radius 2.6 Å. The first solvation shell of an excess electron then contains about 7 ammonia molecules, the second shell about 30 ammonia molecules. This picture is in excellent agreement with interpretation of magnetic resonance data. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2002
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22. Photoluminescence studies of implantation damage centers in (sub 30)Si

Author

Hayama, S., Davies, G., and Itoh, K.M.

Subjects
Phonons -- Analysis, Ion implantation -- Analysis, Photoluminescence -- Usage, Silicon -- Research, Physics
Abstract

The photoluminescence (PL) studies of implantation damage centers in (sub 30)Si are discussed. The data on the host-isotope effects on the zero-phonon lines (ZPLs) of the X and W centers is presented.

Published
2004

25. Photoluminescence studies of implantation damage centers in 30Si.

Author

Hayama, S., Davies, G., and Itoh, K. M.

Subjects
*SILICON, *PHOTOLUMINESCENCE, *PHONONS, *ISOTOPES, *LUMINESCENCE
Abstract

We report photoluminescence (PL) studies of implant-damage centers in 30Si. The X and W zero-phonon lines (ZPLs) shift by +1.55(5) and +1.27(5) meV, respectively, between natSi and 30Si. Using a simple empirical approach, we calculate the shifts to within ∼20%. Local vibrational modes are identified at the X center and confirmed at the W center, supporting the assignment of these centers to self-interstitial clusters. All the strong PL lines produced by ion implantation in the sample have isotope shifts characteristic of ZPLs; they all correspond to independent defect centers, the majority of which have undetermined structures. [ABSTRACT FROM AUTHOR]

Published
2004
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29. Development of radiation hard semiconductor: devices for very high luminosity colliders

Author

Mauro De Palma, D, Radicci, V, Lozano, M, Campabadal, F, Ullán, M, Martínez, C, Fleta, C, Key, M, Raffí, J M, Kordas, G, Kontogeorgakos, A, Trapalis, C, Gössling, C, Klaiber-Lodewigs, J, Klingenberg, R, Krasel, O, Wunstorf, R, Röder, R, Übensee, H, Stolze, D, Jones, R, Coutinho, J, Fall, C, Goss, J, Hourahine, B, Eberlein, T, Adey, J, Blumenau, A, Pinho, N, Borchi, E, Bruzzi, M, Bucciolini, M, Sciortino, S, Menichelli, D, Baldi, A, Lagomarsino, S, Miglio, S, Pini, S, Glaser, M, Joram, C, Moll, M, Rahman, M, O'Shea, V, Bates, R, Roy, P, Cunningham, L, Al-Ajili, A, Pellegrini, G, Horn, M, Haddad, L, Mathieson, K, Gouldwell, A, Bondarenko, V, Krause-Rehberg, R, Fretwurst, E, Lindström, G, Stahl, J, Contarato, D, Buhmann, P, Pein, U, Pintilie, I, Parker, S, Orava, R, Österberg, K, Schulman, T, Lauhakangas, R, Sanna, J, Härkönen, J, Tuominen, E, Lassila-Perini, K M, Nummela, S, Tuovinen, E, Nysten, J, de Boer, Wim, Dierlamm, A, Grigoriev, E, Hauler, F, Jungermann, L, Litovchenko, P, Barabash, L, Lastovetsky, V, Dolgolenko, A, Litovchenko, A P, Karpenko, A, Khivrich, V, Polivtsev, L, Groza, A, Chilingarov, A, Brodbeck, T J, Campbell, D, Hughes, G, Jones, B K, Sloan, T, Allport, P P, Casse, G, Davies, G, Mainwood, A, Hayama, S, Harding, R, Jin, Tan, Assouak, S, Forton, E, Grégoire, G, Murin, L, Kleverman, M, Lindström, L, Zavrtanik, M, Mandic, I, Cindro, V, Mikuz, M, Andreazza, A, Citterio, M, Lari, T, Meroni, C, Ragusa, F, Troncon, C, Leroy, C, Gamaz, F, Genest, M H, Houdayer, A, Lebel, C, Bekenov, B, Golovin, V, Kozodaev, M, Prokop'ev, E, Zaluzhnyi, A, Grafutin, V, Suvorov, A, Ryazanov, A, Litvinov, V, Alexandrov, P, Belova, N, Fanchenko, S, Latushkin, S, Cvetkov, V, Brukhanov, A, Baranova, E, Monakhov, E, Alfieri, G, Kuznetsov, A, Svensson, B G, Kallijärvi, S, Nikkilä, H, Plamu, L, Remes, K, Tuuva, T, Bisello, D, Candelori, A, Litovchenko, A, Rando, R, Messineo, A, Borrello, L, Sentenac, D, Starodumov, A, Worm, S, Schnetzer, S, Stone, R, Perera, L, Sopko, B, Chren, D, Horazdovsky, T, Kohout, Z, Solar, M, Pospísil, S, Linhart, V, Uher, J, Dolezal, Z, Wilhelm, I, Broz, J, Tsvetkov, A, Kodys, P, Popule, J, Tomasek, MPrague, Inst. Phys., Vrba, VPrague, Inst. Phys., Sícho, PPrague, Inst. Phys., Verbitskaya, E, Eremin, V, Ilyashenko, I, Ivanov, A, Strokan, N, Sellin, P, Artuso, Marina, Ruzin, A, Marunko, S, Tilchin, T, Guskov, J, Boscardin, M, Dalla Betta, G F, Gregori, P, Pucker, G, Zen, M, Zorzi, N, Bosisio, L, Dittongo, S, Li, Z, Da Vià, C, Kok, A, Hasi, J, Kuhnke, M, Watts, S, Martí i García, S, García, C, García-Navarro, J E, Horisberger, R, Rohe, T, Vaitkus, J V, Gaubas, E, Jarasiunas, K, Sudzius, M, Jasinskaite, R, Kazukauskas, V, Storasta, J, Sakalauskas, S, Kazlauskiene, V, Luczynski, Z, Nossarzhewska-Orlowska, E, Kozlowski, R, Brzozowski, A, Zabierowski, P, Piatkowski, B, Hruban, A, Strupinski, W, Kowalik, A, Dobrzanski, L, Surma, B, and Barcz, A

Subjects
Detectors and Experimental Techniques
Published
2002

30. Photoluminescence response of ion-implanted silicon

Author

Harding, Ruth E., Davies, Gordon, Hayama, S., Coleman, P. G., Burrows, C. P., Wong-Leung, Jennifer, Harding, Ruth E., Davies, Gordon, Hayama, S., Coleman, P. G., Burrows, C. P., and Wong-Leung, Jennifer

Abstract

The photoluminescence intensity from ion-implanted silicon can be quenched by the radiation damage implicit in the implantation.Annealing is then required before the intensity of the luminescence from a defect center is approximately proportional to the concentration of that center. Data from positron annihilation and photoluminescence experiments establish that severe quenching of the luminescence occurs when the mean separation of the small vacancy clusters is less than ∼30 atomic spacings, and the authors map out where, in the annealing and implantation phase space, the luminescence intensity is expected to be approximately proportional to the concentration of the optical centers.

Published
2006

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