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21 results on '"Schild, N."'

1. Inclusive e$^+$e$^-$ production in collisions of pions with protons and nuclei in the second resonance region of baryons

Author

Yassine, R. Abou, Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Becker, M., Behnke, C., Berger-Chen, J. C., Blanco, A., Blume, C., Böhmer, M., Chlad, L., Chudoba, P., Ciepał, I., Deb, S., Deveaux, C., Dittert, D., Dreyer, J., Epple, E., Fabbietti, L., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Förtsch, J., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Greifenhagen, R., Grunwald, M., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Höhne, C., Hojeij, F., Holzmann, R., Idzik, M., Kämpfer, B., Kampert, K-H., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Lapidus, K., Linev, S., Linz, F., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Mikhaylov, V., Molenda, A., Müntz, C., Münzer, R., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J., Otto, J. -H., Parpottas, Y., Parschau, M., Pauly, C., Pechenov, V., Pechenova, O., Piasecki, K., Pietraszko, J., Povar, T., Prościnki, P., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Scheib, T., Schild, N., Schmidt-Sommerfeld, K., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Spataro, S., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Vazquez-Doce, O., Wagner, V., Weber, A. A., Wendisch, C., Wiebusch, M. G., Wirth, J., Wladyszewska, A, Zbroszczyk, H. P., Zherebtsova, E., Zielinski, M., and Zumbruch, P.

Subjects
Nuclear Experiment
Abstract

Inclusive e$^+$e$^-$ production has been studied with HADES in $\pi^-$ + p, $\pi^-$ + C and $\pi^- + \mathrm{CH}_2$ reactions, using the GSI pion beam at $\sqrt{s_{\pi p}}$ = 1.49 GeV. Invariant mass and transverse momentum distributions have been measured and reveal contributions from Dalitz decays of $\pi^0$, $\eta$ mesons and baryon resonances. The transverse momentum distributions are very sensitive to the underlying kinematics of the various processes. The baryon contribution exhibits a deviation up to a factor seven from the QED reference expected for the dielectron decay of a hypothetical point-like baryon with the production cross section constrained from the inverse $\gamma$ n$\rightarrow \pi^-$ p reaction. The enhancement is attributed to a strong four-momentum squared dependence of the time-like electromagnetic transition form factors as suggested by Vector Meson Dominance (VMD). Two versions of the VMD, that differ in the photon-baryon coupling, have been applied in simulations and compared to data. VMD1 (or two-component VMD) assumes a coupling via the $\rho$ meson and a direct coupling of the photon, while in VMD2 (or strict VMD) the coupling is only mediated via the $\rho$ meson. The VMD2 model, frequently used in transport calculations for dilepton decays, is found to overestimate the measured dielectron yields, while a good description of the data can be obtained with the VMD1 model assuming no phase difference between the two amplitudes. Similar descriptions have also been obtained using a time-like baryon transition form factor model where the pion cloud plays the major role., Comment: (HADES collaboration)

Published
2023

2. Hadron production and propagation in pion-induced reactions on nuclei

Author

Yassine, R. Abou, Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Becker, M., Behnke, C., Berger-chen, J. C., Blanco, A., Blume, C., Böhmer, M., Chlad, L., Chudoba, P., Ciepał, I., Deb, S., Deveaux, C., Dittert, D., Dreyer, J., Epple, E., Fabbietti, L., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Förtsch, J., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Greifenhagen, R., Grunwald, M., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Höhne, C., Hojeij, F., Holzmann, R., Idzik, M., Kämpfer, B., Kampert, K.-H., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Lapidus, K., Linev, S., Linz, F., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Mikhaylov, V., Molenda, A., Müntz, C., Münzer, R., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J., Otto, J. -H., Parpottas, Y., Parschau, M., Pauly, C., Pechenov, V., Pechenova, O., Piasecki, K., Pietraszko, J., Povar, T., Prościński, K., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Scheib, T., Schild, N., Schmidt-Sommerfeld, K., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Spataro, S., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Udrea, I. C., Vazquez-Doce, O., Wagner, V., Weber, A. A., Wendisch, C., Wiebusch, M. G., Wirth, J., Władyszewska, A., Zbroszczyk, H. P., Zherebtsova, E., Zielinski, M., Zumbruch, P., Curceanu, C., Piscicchia, K., and Scordo, A.

Published
2024
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3. Investigation of the $\mathbf{\Sigma^{0}}$ Production Mechanism in p(3.5 GeV)+p Collisions

Author

Yassine, R. Abou, Arnold, O., Becker, M., Bergmann, P., Blanco, A., Blum, C., Böhmer, M., Carolino, N., Chlad, L., Chudoba, P., Ciepał, I., Dreyer, J., Esmail, W., Fabbietti, L., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Grunwald, M., Gumberidze, M., Harabasz, S., Höhne, C., Hojeij, F., Holzmann, R., Huck, H., Idzik, M., Kämpfer, B., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Korcyl, G., Kornakov, G., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Linz, F., Lopes, L., Lorenz, M., Malige, A., Markert, J., Metag, V., Michel, J., Molenda, A., Müntz, C., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J., Otto, J. -H., Parpottas, Y., Parschau, M., Pechenov, V., Pechenova, O., Piasecki, K., Pietraszko, J., Prozorov, A., Przygoda, W., Ramstein, B., Rathod, N., Ritman, J., Rost, A., Rustamov, A., Salabura, P., Schild, N., Schwab, E., Seck, F., Singh, U., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Wagner, V., Weber, A. A., Wendisch, C., Zbroszczyk, H. P., Zherebtsova, E., Zielinski, M., and Zumbruch, P.

Subjects
Nuclear Experiment
Abstract

The production of $\Sigma^0$ hyperons in proton proton collisions at a beam kinetic energy of 3.5 GeV impinging on a liquid hydrogen target was investigated using data collected with the HADES setup. The total production cross section is found to be $\mathrm{\sigma (pK^{+}\Sigma^{0}) [\mu b] = 17.7 \pm 1.7 (stat) \pm 1.6 (syst)}$. Differential cross section distributions of the exclusive channel $\mathrm{pp \rightarrow pK^{+}\Sigma^{0}}$ were analyzed in the center-of-mass, Gottfried-Jackson and helicity reference frames for the first time at the excess energy of 556 MeV. The data support the interplay between pion and kaon exchange mechanisms and clearly demonstrate the contribution of interfering nucleon resonances decaying to $\mathrm{K^{+}\Sigma^{0}}$. The Bonn-Gatchina partial wave analysis was employed to analyse the data. Due to the limited statistics, it was not possible to obtain an unambiguous determination of the relative contribution of intermediate nucleon resonances to the final state. However nucleon resonances with masses around 1.710 $\mathrm{GeV/c^{2}}$ ($\mathrm{N^{*}(1710)}$) and 1.900 $\mathrm{GeV/c^{2}}$ ($\mathrm{N^{*}(1900)}$ or $\mathrm{\Delta^{*}(1900)}$) are preferred by the fit.

Published
2023

4. Production of hydrogen isotopes and charged pions in p (3.5 GeV) + Nb reactions

Author

Yassine, R. Abou, Arnold, O., Becker, M., Bergmann, P., Blanco, A., Blume, C., Böhmer, M., Carolino, N., Chlad, L., Chudoba, P., Ciepał, I., Dreyer, J., Esmail, W. A., Fabbietti, L., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Grunwald, M., Gumberidze, M., Harabasz, S., Höhne, C., Hojeij, F., Holzmann, R., Huck, H., Idzik, M., Kämpfer, B., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Lopes, L., Lorenz, M., Malige, A., Markert, J., Metag, V., Michel, J., Molenda, A., Müntz, C., Naumann, L., Nowakowski, K., Otto, J. -H., Parpottas, Y., Parschau, M., Pechenov, V., Pechenova, O., Pietraszko, J., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Rost, A., Rustamov, A., Salabura, P., Schild, N., Schwab, E., Seck, F., Singh, U., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Wagner, V., Weber, A. A., Wendisch, C., Zbroszczyk, H. P., Zherebtsova, E., Zumbruch, P., Kamys, B., and Sharma, S.

Subjects
Nuclear Experiment
Abstract

The double differential production cross sections, $d^2\sigma/d\Omega dE$, for hydrogen isotopes and charged pions in the reaction of p + Nb at 3.5 GeV proton beam energy have been measured by the High Acceptance DiElectron Spectrometer (HADES). Thanks to the high acceptance of HADES at forward emission angles and usage of its magnetic field, the measured energy range of hydrogen isotopes could be significantly extended in comparison to the relatively scarce experimental data available in the literature. The data provide information about the development of the intranuclear cascade in the proton-nucleus collisions. They can as well be utilized to study the rate of energy/momentum dissipation in the nuclear systems and the mechanism of elementary and composite particle production in excited nuclear matter at normal density. Data of this type are important also for technological and medical applications. Our results are compared to models developed to describe the processes relevant to nuclear spallation (INCL++) or oriented to probe either the elementary hadronic processes in nuclear matter or the behavior of compressed nuclear matter (GiBUU).

Published
2023

5. Hadron Production and Propagation in Pion-Induced Reactions on Nuclei

Author

Yassine, R. Abou, Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Becker, M., Behnke, C., Berger-Chen, J. C., Blanco, A., Blume, C., Böhmer, M., Chlad, L., Chudoba, P., Ciepał, I., Deveaux, C., Dittert, D., Dreyer, J., Epple, E., Fabbietti, L., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Förtsc, J., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Greifenhagen, R., Grunwald, M., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Höhne, C., Hojeij, F., Holzmann, R., Idzik, M., Kämpfer, B., Kampert, K-H., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Lapidus, K., Linev, S., Linz, F., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Mikhaylov, V., Molenda, A., Müntz, C., Münzer, R., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J., Otto, J. -H., Parpottas, Y., Parschau, M., Pauly, C., Pechenov, V., Pechenova, O., Piasecki, K., Pietraszko, J., Povar, T., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Scheib, T., Schild, N., Schmidt-Sommerfeld, K., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Spataro, S., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Vazquez-Doce, O., Wagner, V., Weber, A. A., Wendisch, C., Wiebusch, M. G., Wirth, J., Zbroszczyk, H. P., Zherebtsova, E., Zumbruch, P., Curceanu, C., Piscicchia, K., and Scordo, A.

Subjects
Nuclear Experiment
Abstract

Hadron production ($\pi^\pm$, proton, $\Lambda$, $K_S^0$, $K^\pm$) in $\pi^- + \mathrm{C}$ and $\pi^- + \mathrm{W}$ collisions is investigated at an incident pion beam momentum of $1.7~\mathrm{GeV}/c$. This comprehensive set of data measured with HADES at SIS18/GSI significantly extends the existing world data on hadron production in pion induced reactions and provides a new reference for models that are commonly used for the interpretation of heavy-ion collisions. The measured inclusive differential production cross-sections are compared with state-of-the-art transport model (GiBUU, SMASH) calculations. The (semi-) exclusive channel $\pi^- + A \rightarrow \Lambda + K_S^0 +X$, in which the kinematics of the strange hadrons are correlated, is also investigated and compared to a model calculation. Agreement and remaining tensions between data and the current version of the considered transport models are discussed.

Published
2023

6. Measurement of global polarization of {\Lambda} hyperons in few-GeV heavy-ion collisions

Author

Yassine, R. Abou, Adamczewski-Musch, J., Asal, C., Becker, M., Belounnas, A., Blanco, A., Blume, C., Chlad, L., Chudoba, P., Ciepal, I., Cordts, M., Dreyer, J., Esmail, W. A., Fabbietti, L., Floersheimer, H., Fonte, P., Friese, J., Fröhlich, I., Förtsch, J., Galatyuk, T., Gniazdowski, T, Greifenhagen, R., Grunwald, M., Gumberidze, M., Harabasz, S., Heinz, T., Höhne, C., Hojeij, F., Holzmann, R., Huck, H., Idzik, M., Kämpfer, B., Kampert, K-H., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Kornakov, G., Kotte, R., Kres, I., Krueger, W., Kugler, A., Lalik, R., Lebedev, S., Linev, S., Linz, F., Lopes, L., Lorenz, M., Malige, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Molenda, A., Müntz, C., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J., Otto, J. -H., Parschau, M., Pauly, C., Pechenov, V., Pechenova, O., Pfeifer, D., Piasecki, K., Pietraszko, J., Povar, T., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Ritman, J., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Saraiva, J., Schild, N., Schwab, E., Scozzi, F., Seck, F., Selyuzhenkov, I., Singh, U., Skorpil, L., Smyrski, J., Spies, S., Stefaniak, M. S., Ströbele, H., Stroth, J., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Wagner, V., Wasiluk, M., Weber, A. A., Wendisch, C., Wirth, J., Zbroszczyk, H. P., Zherebtsova, E., Zielinski, M., and Zumbruch, P.

Subjects
Nuclear Experiment
Abstract

The global polarization of {\Lambda} hyperons along the total orbital angular momentum of a relativistic heavy-ion collision is presented based on the high statistics data samples collected in Au+Au collisions at \sqrt{s_{NN}} = 2.4 GeV and Ag+Ag at 2.55 GeV with the High-Acceptance Di-Electron Spectrometer (HADES) at GSI, Darmstadt. This is the first measurement below the strangeness production threshold in nucleon-nucleon collisions. Results are reported as a function of the collision centrality as well as a function of the hyperon transverse momentum (p_T) and rapidity (y_{CM}) for the range of centrality 0--40%. We observe a strong centrality dependence of the polarization with an increasing signal towards peripheral collisions. For mid-central (20--40%) collisions the polarization magnitudes are (%) = 6.8 \pm 1.3 (stat.) \pm 2.1 (syst.) for Au+Au and (%) = 6.2 \pm 0.4 (stat.) \pm 0.6 (syst.) for Ag+Ag, which are the largest values observed so far. This observation thus provides a continuation of the increasing trend previously observed by STAR and contrasts expectations from recent theoretical calculations predicting a maximum in the region of collision energies about 3 GeV. The observed polarization is of a similar magnitude as predicted by 3D fluid dynamics and the UrQMD plus thermal vorticity model and significantly above results from the AMPT model., Comment: 8 pages, 4 figures

Published
2022
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7. First measurement of massive virtual photon emission from N* baryon resonances

Author

Yassine, R. Abou, Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Becker, M., Behnke, C., Berger-Chen, J. C., Blanco, A., Blume, C., Böhmer, M., Chlad, L., Chudoba, P., Ciepał, I., Deb, S., Deveaux, C., Dittert, D., Dreyer, J., Epple, E., Fabbietti, L., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Fortsch, J., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Greifenhagen, R., Grunwald, M., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Höhne, C., Hojeij, F., Holzmann, R., Idzik, M., Kämpfer, B., Kampert, K-H., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Lapidus, K., Linev, S., Linz, F., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Mikhaylov, V., Molenda, A., Müntz, C., Münzer, R., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J., Otto, J. -H., Parpottas, Y., Parschau, M., Pauly, C., Pechenov, V., Pechenova, O., Piasecki, K., Pietraszko, J., Povar, T., Prościński, K., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Scheib, T., Schild, N., Schmidt-Sommerfeld, K., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Spataro, S., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Udrea, I. C., Vazquez-Doce, O., Wagner, V., Weber, A. A., Wendisch, C., Wiebusch, M. G., Wirth, J., Władyszewska, A., Zbroszczyk, H. P., Zherebtsova, E., Zieliński, M., Zumbruch, P., and Zetenyi, M.

Subjects
Nuclear Experiment
Abstract

First information on the time-like electromagnetic structure of baryons in the second resonance region has been obtained from measurements of dielectron (e+ e-) invariant-mass and angular distributions in the quasi-free reaction $\pi-$ p $\rightarrow$ n e+ e- at $\sqrt{s_{\pi p}}$ = 1.49 GeV with the High Acceptance Di-Electron Spectrometer (HADES) at GSI using the pion beam impinging on a CH$_2$ target. We find a total cross section $\sigma$ = 2.97 $\pm$ 0.07data $\pm$ 0.21acc $\pm$ 0.31Zeff $\mu$b. In complement to the analysis of the inclusive e+ e- channel, this data set provides a crucial test of the description of baryon time-like transitions. Approaches based on a Vector Meson Dominance amplitude containing direct photon and vector meson ($\rho$) couplings to the baryon provide a satisfactory agreement with the data. A good description is also obtained by electromagnetic time-like baryon transition form factors in a covariant spectator-quark model, pointing to the dominance of meson-cloud effects. The dielectron angular distributions exhibit the contributions of virtual photons ($\gamma^*$) with longitudinal polarization, in contrast to real photons. The virtual photon angular dependence supports the dominance of J=3/2, I=1/2 contributions observed in both the $\gamma^*$n and the $\pi \pi$n channels., Comment: revised version, 7 pages, 3 figures

Published
2022

8. Impact of the Coulomb field on charged-pion spectra in few-GeV heavy-ion collisions

Author

Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Ciepał, I., Deveaux, C., Dreyer, J., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kohls, M., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Linev, S., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Nabroth, M., Naumann, L., Nowakowski, K., Parpottas, Y., Parschau, M., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Pysz, K., Ramos, S., Ramstein, B., Rathod, N., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schild, N., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Sobolev, Yu. G., Spataro, S., Spies, S., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., and Zumbruch, P.

Subjects
Nuclear Experiment
Abstract

In nuclear collisions the incident protons generate a Coulomb field which acts on produced charged particles. The impact of these interactions on charged pion transverse-mass and rapidity spectra, as well as on pion-pion momentum correlations is investigated in Au+Au collisions at $\sqrt{s_{NN}}$ = 2.4 GeV. We show that the low-mt part of the data ($m_t < 0.2$ GeV/c$^2$) can be well described with a Coulomb-modified Boltzmann distribution that also takes changes of the Coulomb field during the expansion of the fireball into account. The observed centrality dependence of the fitted mean Coulomb potential deviates strongly from a $A_{part}^{2/3}$ scaling, indicating that, next to the fireball, the non-interacting charged spectators have to be taken into account. For the most central collisions, the Coulomb modifications of the HBT source radii are found to be consistent with the potential extracted from the single-pion transverse-mass distributions. This finding suggests that the region of homogeneity obtained from two-pion correlations coincides with the region in which the pions freeze-out. Using the inferred mean-square radius of the charge distribution at freeze-out, we have deduced a baryon density, in fair agreement with values obtained from statistical hadronization model fits to the particle yields., Comment: 14 pages, 12 figures, to be published in EPJA

Published
2022
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9. Investigation of the Σ0 Production Mechanism in p(3.5 GeV)+p Collisions

Author

Yassine, R. Abou, Arnold, O., Becker, M., Bergmann, P., Blanco, A., Blume, C., Böhmer, M., Carolino, N., Chlad, L., Chudoba, P., Ciepał, I., Dreyer, J., Esmail, W., Fabbietti, L., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Grunwald, M., Gumberidze, M., Harabasz, S., Höhne, C., Hojeij, F., Holzmann, R., Huck, H., Idzik, M., Kämpfer, B., Kardan, B., Kedych, V., Koenig, I., Koenig, W., Kohls, M., Kolas, J., Korcyl, G., Kornakov, G., Kotte, R., Krueger, W., Kugler, A., Kunz, T., Lalik, R., Linz, F., Lopes, L., Lorenz, M., Malige, A., Markert, J., Metag, V., Michel, J., Molenda, A., Müntz, C., Nabroth, M., Naumann, L., Nowakowski, K., Orliński, J. , Otto, J. -H., Parpottas, Y., Parschau, M., Pechenov, V., Pechenova, O., Piasecki, K., Pietraszko, J., Prozorov, A., Przygoda, W., Ramstein, B., Rathod, N., Ritman, J., Rost, A., Rustamov, A., Salabura, P., Schild, N., Schwab, E., Seck, F., Singh, U., Spies, S., Stefaniak, M., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Wagner, V., Weber, A. A., Wendisch, C., Zbroszczyk, H. P., Zherebtsova, E., Zielinski, M., and Zumbruch, P.

Published
2024
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10. Production and electromagnetic decay of hyperons: a feasibility study with HADES as a Phase-0 experiment at FAIR

Author

Adamczewski-Musch, J., Belyaev, A., Blanco, A., Blume, C., Charlotte, C., Borisenko, D. S., Chlad, L., Chudoba, P., Ciepał, I., Derichs, A., Dittert, D., Dreyer, J., Esmail, W. A., Fateev, O., Fonte, P., Friese, J., Fröhlich, I., Förtsch, J., Galatyuk, T., Georgadze, I., Golosov, O., Golubeva, M., Greifenhagen, R., Grunwald, M., Grzonka, D., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Heybeck, B., Höhne, C., Holona, M., Holzmann, R., Huck, H., Ierusalimov, A., Imre, M., Ivashkin, A., Kämpfer, B., Kampert, K-H., Kardan, B., Kedych, V., Khomyakov, V., Koenig, I., Koenig, W., Kohls, M., Kornakov, G., Kornas, F., Kotte, R., Kozela, A., Kozlov, V., Kres, I., Kuboś, J., Kugler, A., Kulessa, P., Ladygin, V., Lalik, R., Galliard, C. Le, Lebedev, A., Lebedev, S., Linev, S., Lopes, L., Lorenz, M., Lykasov, G., Malige, A., Markert, J., Matulewicz, T., Michel, J., Morozov, S., Müntz, C., Naumann, L., Nowakowski, K., Orfanitsky, S., Otto, J. -H., Patel, V., Pauly, C., Pechenov, V., Pechenova, O., Andrade, G. Perez, Petukhov, O., Pfeifer, D., Piasecki, K., Pietraszko, J., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Regina, J., Reshetin, A., Reznikov, S., Rieger, J. T., Ritman, J., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Saraiva, J., Schild, N., Schwab, E., Schönning, K., Scozzi, F., Seck, F., Selyuzhenkov, I., Serdyuk, V., Shabanov, A., Singh, U., Smyrski, J., Sobiella, M., Spies, S., Strikhanov, M., Ströbele, H., Stroth, J., Sumara, K., Svoboda, O., Szala, M., Szewczyk, J., Taranenko, A., Tlusty, P., Traxler, M., Wagner, V., Wasiluk, M., Weber, A. A., Wendisch, C., Wintz, P., Włoch, B., Zbroszczyk, H. P., Zherebzova, E., Zhilin, A., Zinchenko, A., and Zumbruch, P.

Subjects
Nuclear Experiment
Abstract

A feasibility study has been performed in order to investigate the performance of the HADES detector to measure the electromagnetic decays of the hyperon resonances $\Sigma(1385)^0$, $\Lambda(1405)$ and $\Lambda{\Lambda}(1520)$ as well as the production of double strange baryon systems $\Xi^-$ and $\Lambda\Lambda$ in p+p reactions at a beam kinetic energy of 4.5 GeV. The existing HADES detector will be upgraded by a new Forward Detector, which extends the detector acceptance into a range of polar angles that plays a crucial role for these investigations. The analysis of each channel is preceded by a consideration of the production cross-sections. Afterwards the expected signal count rates using a target consisting of either liquid hydrogen or polyethylene are summarized., Comment: Draft prepared by Rafa{\l} Lalik, James Ritman, Piotr Salabura, 19 pages, 21 figures, 4 tables

Published
2020
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11. Production and electromagnetic decay of hyperons: a feasibility study with HADES as a phase-0 experiment at FAIR

Author

Adamczewski-Musch, J., Belyaev, A., Blanco, A., Blume, C., Charlotte, C., Borisenko, D. S., Charlotte, C., Chlad, L., Chudoba, P., Ciepał, I., Derichs, A., Dittert, D., Dreyer, J., Esmail, W., Fateev, O., Fonte, P., Friese, J., Fröhlich, I., Förtsch, J., Galatyuk, T., Georgadze, I., Golosov, O., Golubeva, M., Greifenhagen, R., Grunwald, M., Grzonka, D., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Heybeck, B., Höhne, C., Holona, M., Holzmann, R., Huck, H., Ierusalimov, A., Imre, M., Ivashkin, A., Kämpfer, B., Kampert, K-H., Kardan, B., Kedych, V., Khomyakov, V., Koenig, I., Koenig, W., Kohls, M., Kornakov, G., Kornas, F., Kotte, R., Kozela, A., Kozlov, V., Kres, I., Kuboś, J., Kugler, A., Kulessa, P., Ladygin, V., Lalik, R., Le Galliard, C., Lebedev, A., Lebedev, S., Linev, S., Lopes, L., Lorenz, M., Lykasov, G., Malige, A., Markert, J., Matulewicz, T., Michel, J., Morozov, S., Müntz, C., Naumann, L., Nowakowski, K., Orfanitsky, S., Otto, J. -H., Patel, V., Pauly, C., Pechenov, V., Pechenova, O., Perez Andrade, G., Petukhov, O., Pfeifer, D., Piasecki, K., Pietraszko, J., Prozorov, A., Przygoda, W., Pysz, K., Ramstein, B., Rathod, N., Regina, J., Reshetin, A., Reznikov, S., Rieger, J. T., Ritman, J., Rodriguez-Ramos, P., Rost, A., Rustamov, A., Salabura, P., Saraiva, J., Schild, N., Schwab, E., Schönning, K., Scozzi, F., Seck, F., Selyuzhenkov, I., Serdyuk, V., Shabanov, A., Singh, U., Smyrski, J., Sobiella, M., Spies, S., Strikhanov, M., Ströbele, H., Stroth, J., Sumara, K., Svoboda, O., Szala, M., Szewczyk, J., Taranenko, A., Tlusty, P., Traxler, M., Wagner, V., Wasiluk, M., Weber, A. A., Wendisch, C., Wintz, P., Włoch, B., Zbroszczyk, H. P., Zherebzova, E., Zhilin, A., Zinchenko, A., and Zumbruch, P.

Published
2021
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12. Measurement of global polarization of Λ hyperons in few-GeV heavy-ion collisions

Author

Abou Yassine, R., primary, Adamczewski-Musch, J., additional, Asal, C., additional, Becker, M., additional, Belounnas, A., additional, Blanco, A., additional, Blume, C., additional, Chlad, L., additional, Chudoba, P., additional, Ciepał, I., additional, Cordts, M., additional, Dreyer, J., additional, Esmail, W.A., additional, Fabbietti, L., additional, Floersheimer, H., additional, Fonte, P., additional, Friese, J., additional, Fröhlich, I., additional, Förtsch, J., additional, Galatyuk, T., additional, Gniazdowski, T., additional, Greifenhagen, R., additional, Grunwald, M., additional, Gumberidze, M., additional, Harabasz, S., additional, Heinz, T., additional, Höhne, C., additional, Hojeij, F., additional, Holzmann, R., additional, Huck, H., additional, Idzik, M., additional, Kämpfer, B., additional, Kampert, K-H., additional, Kardan, B., additional, Kedych, V., additional, Koenig, I., additional, Koenig, W., additional, Kohls, M., additional, Kolas, J., additional, Kornakov, G., additional, Kotte, R., additional, Kres, I., additional, Krueger, W., additional, Kugler, A., additional, Lalik, R., additional, Lebedev, S., additional, Linev, S., additional, Linz, F., additional, Lopes, L., additional, Lorenz, M., additional, Malige, A., additional, Markert, J., additional, Matulewicz, T., additional, Maurus, S., additional, Metag, V., additional, Michel, J., additional, Molenda, A., additional, Müntz, C., additional, Nabroth, M., additional, Naumann, L., additional, Nowakowski, K., additional, Orliński, J., additional, Otto, J.-H., additional, Parschau, M., additional, Pauly, C., additional, Pechenov, V., additional, Pechenova, O., additional, Pfeifer, D., additional, Piasecki, K., additional, Pietraszko, J., additional, Povar, T., additional, Prozorov, A., additional, Przygoda, W., additional, Pysz, K., additional, Ramstein, B., additional, Rathod, N., additional, Ritman, J., additional, Rodriguez-Ramos, P., additional, Rost, A., additional, Rustamov, A., additional, Salabura, P., additional, Saraiva, J., additional, Schild, N., additional, Schwab, E., additional, Scozzi, F., additional, Seck, F., additional, Selyuzhenkov, I., additional, Singh, U., additional, Skorpil, L., additional, Smyrski, J., additional, Spies, S., additional, Stefaniak, M.S., additional, Ströbele, H., additional, Stroth, J., additional, Sumara, K., additional, Svoboda, O., additional, Szala, M., additional, Tlusty, P., additional, Traxler, M., additional, Wagner, V., additional, Wasiluk, M., additional, Weber, A.A., additional, Wendisch, C., additional, Wirth, J., additional, Zbroszczyk, H.P., additional, Zherebtsova, E., additional, Zielinski, M., additional, and Zumbruch, P., additional

Published
2022
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13. HADES Collaboration

Author

Adamczewski-Musch, J., primary, Belyaev, A., additional, Blanco, A., additional, Blume, C., additional, Böhmer, M., additional, Asal, C., additional, Chlad, L., additional, Chudoba, P., additional, Ciepał, I., additional, Dittert, D., additional, Dreyer, J., additional, Esmail, W.A., additional, Fabbietti, L., additional, Fateev, O., additional, Fonte, P., additional, Friese, J., additional, Fröhlich, I., additional, Förtsch, J., additional, Galatyuk, T., additional, Gernhäuser, R., additional, Golosov, O., additional, Golubeva, M., additional, Greifenhagen, R., additional, Grunwald, M., additional, Grzonka, D., additional, Guber, F., additional, Gumberidze, M., additional, Harabasz, S., additional, Heybeck, B., additional, Höhne, C., additional, Holzmann, R., additional, Huck, H., additional, Ierusalimov, A., additional, Ivashkin, A., additional, Kämpfer, B., additional, Kampert, K-H., additional, Kardan, B., additional, Kedych, V., additional, Khomyakov, V., additional, Koenig, I., additional, Koenig, W., additional, Kohls, M., additional, Korcyl, G., additional, Kornakov, G., additional, Kornas, F., additional, Kotte, R., additional, Kozela, A., additional, Kres, I., additional, Krueger, W., additional, Kuboś, J., additional, Kugler, A., additional, Kulessa, P., additional, Ladygin, V., additional, Lalik, R., additional, Lebedev, A., additional, Lebedev, S., additional, Linev, S., additional, Lopes, L., additional, Lorenz, M., additional, Lykasov, G., additional, Malige, A., additional, Markert, J., additional, Matulewicz, T., additional, Maurus, S., additional, Metag, V., additional, Michel, J., additional, Morozov, S., additional, Müntz, C., additional, Naumann, L., additional, Nowakowski, K., additional, Otto, J.-H., additional, Patel, V., additional, Pauly, C., additional, Pechenov, V., additional, Pechenova, O., additional, Perez Andrade, G.P., additional, Petukhov, O., additional, Pfeifer, D., additional, Piasecki, K., additional, Pietraszko, J., additional, Prozorov, A., additional, Przygoda, W., additional, Pysz, K., additional, Ramstein, B., additional, Rathod, N., additional, Reshetin, A., additional, Reznikov, S., additional, Ritman, J., additional, Rodriguez-Ramos, P., additional, Rost, A., additional, Rustamov, A., additional, Salabura, P., additional, Saraiva, J., additional, Schild, N., additional, Scozzi, F., additional, Seck, F., additional, Selyuzhenkov, I., additional, Shabanov, A., additional, Singh, U., additional, Smyrski, J., additional, Spies, S., additional, Strikhanov, M., additional, Ströbele, H., additional, Stroth, J., additional, Sumara, K., additional, Svoboda, O., additional, Szala, M., additional, Szewczyk, J., additional, Taranenko, A., additional, Tlusty, P., additional, Traxler, M., additional, Wagner, V., additional, Wasiluk, M., additional, Weber, A.A., additional, Wendisch, C., additional, Wintz, P., additional, Wirth, J., additional, Włoch, B., additional, Zbroszczyk, H.P., additional, Zherebzova, E., additional, Zhilin, A., additional, Zinchenko, A., additional, and Zumbruch, P., additional

Published
2021
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15. Optimisation of the calibration process of a k-tls based multi-sensor-system by genetic algorithms

Author

Hartmann, J., Von Gösseln, I., Schild, N., Dorndorf, A., Paffenholz, J.-A., Neumann, I., Vosselman, G., Oude, Elberink, S.J., and Yang, M.Y.

Subjects
lcsh:Applied optics. Photonics, Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften, Terrestrial laser scanning, Kinematics, Laser scanning, Computer science, Object detection, Qualitative assessments, Kinematic Laser Scanning, Geometry, lcsh:Technology, Genetic algorithm, Calibration, ddc:550, Seebeck effect, Optimisation, Scanning, Steel beams and girders, Konferenzschrift, Genetic Algorithm, Birefringence, Orientation (computer vision), lcsh:T, lcsh:TA1501-1820, Genetic algorithms, Industrial production, lcsh:TA1-2040, (Geo-)referencing, Surveying instruments, Uncertainty propagation, Uncertainty analysis, Position and orientations, Focus (optics), lcsh:Engineering (General). Civil engineering (General), Algorithm, Optimisations, Laser applications
Abstract

In recent years, the requirements in the industrial production of elongated objects, e.g., aircraft, have been increased. An essential aspect of the production process is the 3D object detection as well as the qualitative assessment of the captured data. On the one hand high accuracy requirements with a 3D standard deviation of σ3D = 1 mm have to be fulfilled, on the other hand an efficient 3D object capturing is needed. In terms of efficiency, kinematic terrestrial laser scanning (k-TLS) has proven its strength in the recent years. It can be seen as an alternative and is even more powerful than to the well established static terrestrial laser scanning (s-TLS). In order to perform a high accurate 3D object capturing with k-TLS, the 3D object capturing of the initial sensor, the (geo-)referencing of the mobile platform, the synchronisation of all sensors and the system calibration, which means the determination of six extrinsic parameters have to be performed with suitable accuracy. Within this contribution we focus on the system calibration. Therefore an approach based on known reference geometries, here planes, is used (Strübing and Neumann, 2013). As a result, the lever arm and boresight angles are determined. Hereby the number as well as the position and orientation of the reference geometries is of importance. Therefore, an optimal arrangement has to be found. Here a sensitive analysis based on uncertainty propagation is used. A selective search of an optimised arrangement is carried out by a genetic algorithm. Within some examples we demonstrate some theoretical aspects and how an optimisation of the reference geometry arrangement can be achieved.

Published
2019

16. Optimisation of the calibration process of a k-tls based multi-sensor-system by genetic algorithms

Author

Vosselman, G., Oude, Elberink, S.J., Yang, M.Y., Hartmann, J., Von Gösseln, I., Schild, N., Dorndorf, A., Paffenholz, J.-A., Neumann, I., Vosselman, G., Oude, Elberink, S.J., Yang, M.Y., Hartmann, J., Von Gösseln, I., Schild, N., Dorndorf, A., Paffenholz, J.-A., and Neumann, I.

Abstract

In recent years, the requirements in the industrial production of elongated objects, e.g., aircraft, have been increased. An essential aspect of the production process is the 3D object detection as well as the qualitative assessment of the captured data. On the one hand high accuracy requirements with a 3D standard deviation of σ3D Combining double low line 1 mm have to be fulfilled, on the other hand an efficient 3D object capturing is needed. In terms of efficiency, kinematic terrestrial laser scanning (k-TLS) has proven its strength in the recent years. It can be seen as an alternative and is even more powerful than to the well established static terrestrial laser scanning (s-TLS). In order to perform a high accurate 3D object capturing with k-TLS, the 3D object capturing of the initial sensor, the (geo-)referencing of the mobile platform, the synchronisation of all sensors and the system calibration, which means the determination of six extrinsic parameters have to be performed with suitable accuracy. Within this contribution we focus on the system calibration. Therefore an approach based on known reference geometries, here planes, is used (Strübing and Neumann, 2013). As a result, the lever arm and boresight angles are determined. Hereby the number as well as the position and orientation of the reference geometries is of importance. Therefore, an optimal arrangement has to be found. Here a sensitive analysis based on uncertainty propagation is used. A selective search of an optimised arrangement is carried out by a genetic algorithm. Within some examples we demonstrate some theoretical aspects and how an optimisation of the reference geometry arrangement can be achieved.

Published
2019

18. Ein neuartiges Seidenfibroin Scaffold für den Meniskusersatz zeigt annähernd physiologische Reibungseigenschaften

Author

Warnecke, D, Schild, N, Klose, S, Skaer, N, Kessler, O, Ignatius, A, and Dürselen, L

Subjects
Seide, Meniskus, ddc: 610, Meniskektomie, Reibung, 610 Medical sciences, Medicine, Meniskusersatz, Tribologie, Synovialflüssigkeit
Abstract

Fragestellung: Die partielle Meniskektomie ist der Gold-Standard zur Behandlung von Meniskusverletzungen. Sie führt jedoch nachweislich zur Osteoarthrose (Fairbank, 1948; Seitz et al., 2012). Veranlasst durch das oberste Therapieziel, den Meniskus weitestgehend zu erhalten und/oder zu ersetzen,[zum vollständigen Text gelangen Sie über die oben angegebene URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2016)

Published
2016
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19. Degeneration alters the biomechanical properties and structural composition of lateral human menisci.

Author

Warnecke D, Balko J, Haas J, Bieger R, Leucht F, Wolf N, Schild NB, Stein SEC, Seitz AM, Ignatius A, Reichel H, Mizaikoff B, and Dürselen L

Subjects
Aged, Biomechanical Phenomena, Cartilage Diseases metabolism, Cartilage Diseases pathology, Compressive Strength, Female, Humans, Male, Menisci, Tibial metabolism, Menisci, Tibial pathology, Middle Aged, Osteoarthritis, Knee metabolism, Osteoarthritis, Knee pathology, Spectrum Analysis, Tensile Strength, Arthroplasty, Replacement, Knee, Cartilage Diseases physiopathology, Collagen, Menisci, Tibial physiopathology, Osteoarthritis, Knee physiopathology, Proteoglycans
Abstract

Objective: Because the literature relating to the influence of degeneration on the viscoelasticity and tissue composition of human lateral menisci remains contradictory or completely lacking, the aim of this study was to fill these gaps by comprehensively characterising the biomechanical properties of menisci with regard to the degree of degeneration., Design: Meniscal tissue from 24 patients undergoing a total knee replacement was collected and the degeneration of each region classified according to Pauli et al. For biomechanical characterisation, compression and tensile tests were performed. Additionally, the water content was determined and infrared (IR) spectroscopy was applied to detect changes in the structural composition, particularly of the proteoglycan and collagen content., Results: With an increasing degree of degeneration, a significant decrease of the equilibrium modulus was detected, while simultaneously the water content and the hydraulic permeability significantly increased. However, the tensile modulus displayed a tendency to decrease with increasing degeneration, which might be due to the significantly decreasing amount of collagen content identified by the IR measurements., Conclusion: The findings of the current study may contribute to the understanding of meniscus degeneration, showing that degenerative processes appear to mainly worsen viscoelastic properties of the inner circumference by disrupting the collagen integrity., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Published
2020
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20. A biomechanical comparison of two plating techniques in lateral clavicle fractures.

Author

Suter C, von Rohr M, Majewski M, Dürselen L, Warnecke D, Schild N, and Nowakowski AM

Subjects
Aged, Biomechanical Phenomena, Cadaver, Female, Humans, Joint Dislocations, Male, Middle Aged, Osteotomy, Stress, Mechanical, Bone Plates, Clavicle surgery, Fracture Fixation, Internal methods, Fractures, Bone surgery
Abstract

Background: Neer Type IIb lateral clavicle fractures typically lead to dislocation of the medial fragment. Therefore, most surgeons recommend surgical treatment for such a fracture pattern. The use of a locking compression plate with a lateral extension has produced satisfactory results in various studies over recent years. Double-plate fixation is a common technique in the treatment of complex distal radius fractures. The authors use this technique as a routine procedure in the treatment of Neer type IIb fractures. In this biomechanical testing study, the mechanical properties of the two techniques were compared., Methods: On 20 clavicles from fresh frozen cadavers a Neer Type IIb fracture-like osteotomy was performed. A cyclic loading test followed by a load-to-failure test was carried out. Parameters for statistical evaluation were the stiffness at cycles 1, 100 and 17,500 as well as the ultimate tensile load and the deformation at the point of failure., Findings: All specimens withstood the cyclic loading test without any noticeable damage. At cycles 100 and 17,500, the double-plate technique was less stiff. Failure loads were not significantly different from each other, but deformation at the point of failure was significantly greater for the double-plate technique., Interpretation: Both techniques provided sufficient fixation to the fracture site to endure the cyclic loading test, which is supposed to simulate an incident-free week postoperatively. In summary, the double-plate technique offers biomechanically a feasible alternative to the single-plate technique in lateral clavicle fractures of Neer Type IIb., (Copyright © 2019. Published by Elsevier Ltd.)

Published
2019
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21. Friction properties of a new silk fibroin scaffold for meniscal replacement.

Author

Warnecke D, Schild NB, Klose S, Joos H, Brenner RE, Kessler O, Skaer N, Walker R, Freutel M, Ignatius A, and Dürselen L

Abstract

The menisci protect the articular cartilage by reducing contact pressure in the knee. To restore their function after injury, a new silk fibroin replacement scaffold was developed. To elucidate its tribological properties, friction of the implant was tested against cartilage and glass, where the latter is typically used in tribological cartilage studies. The silk scaffold exhibited a friction coefficient against cartilage of 0.056, which is higher than meniscus against cartilage but in range of the requirements for meniscal replacements. Further, meniscus friction against glass was lower than cartilage against glass, which correlated with the surface lubricin content. Concluding, the tribological properties of the new material suggest a possible long-term chondroprotective function. In contrast, glass always produced high, non-physiological friction coefficients.

Published
2017
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