| 1. |
- Marcouille, O., et al.
(författare)
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Production of high energy photons with in vacuum wigglers : From SOLEIL wiggler to MAXIV wiggler
- 2019
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Ingår i: Proceedings of the 13th International Conference on Synchrotron Radiation Instrumentation, SRI 2018. - : Author(s). - 9780735417823 ; 2054
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Konferensbidrag (refereegranskat)abstract
- Small gap wigglers become more and more attractive to produce high photon fluxes in the hard X-ray photon range. They use magnet blocks of high magnetization which resists much better to heating (baking, synchrotron radiation) than in the past, produce high magnetic field with numerous periods and are very compact. They also are a very good alternative to superconducting technology which requires special infrastructure, heavy maintenance and is not running cost free. SOLEIL, operating presently at 2.75 GeV has designed and built an in-vacuum wiggler of 38 periods of 50 mm producing 2.1 T at a minimum gap of 5.5 mm to delivered photon beam between 20 keV and 50 keV. Already in operation, further improvements are presently in progress to push photons towards higher energy, in particular thanks to the operation at lower gap (4.5 mm). MAX IV and SOLEIL, in the frame of collaboration, ave built an upgraded version of the existing SOLEIL wiggler with the target to extend the spectral range at high energy (above 50 keV) but also at low energy (4 keV) with the same insertion device. The design of the existing magnetic system has been modified to reach 2.4 T at a minimum gap of 4.2 mm and includes taper operation to avoid undulator structure in the radiated spectrum at low energy.
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| 2. |
- Khorrami, F., et al.
(författare)
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An up-to-date block model and strain rate map of Iran using integrated campaign-mode and permanent GPS velocities
- 2019
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Ingår i: 27th IUGG General Assembly.
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Konferensbidrag (refereegranskat)abstract
- Iran accommodates a large part of the ongoing Arabia-Eurasia collision deformation. Because of such active tectonics, the country suffers from intensive seismicity and frequent destructive earthquakes in different locations.To study further the crustal deformation in Iran, we processed the data collected during 10 years (2006-2015) from the Iranian Permanent GNSS Network and combined them with previously published velocity solutions from GPS survey measurements during 1997–2013. We analysed this velocity field using a continuum approach to compute a new strain rate map for this region and we designed a block model based on the main geological, morphological, and seismic structures. Comparison between both approaches suggests similar results and allow us to present the first comprehensive first order fault slip rate estimates for the whole of Iran. Our results confirm most of the results from previous geodetic studies. Moreover, we also show a trade-off between the coupling ratio of the Iranian Makran subduction interface and the kinematic of the faults north of the Makran in the Jazmurian depression. Although too scarce to accurately estimate a coupling ratio, we show that coupling higher than 0.4 on the plate interface down to a depth of 25 km will induce extension on the E-W faults in the Jazmurian region. However, the sites close to the shoreline suggest a low coupling ratio, hence the coupling on this plate interface is probably more complicated than previously described and the Iranian Makran subduction interface mechanical behaviour might be similar to that on the Hellenic subduction zone.
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| 3. |
- Bilandi, R. N., et al.
(författare)
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A numerical and analytical way for double-stepped planing hull in regular wave
- 2019
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Ingår i: 8th International Conference on Computational Methods in Marine Engineering, MARINE 2019. - : International Center for Numerical Methods in Engineering. ; , s. 417-427
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Konferensbidrag (refereegranskat)abstract
- The paper presents a comparison analysis between numerical method and nonlinear mathematical model for the prediction of the vertical motions of a double stepped planing hull in regular wave. The numerical method is to Unsteady Reynolds Averaged Navier-Stokes (URANS) equations solution via moving mesh techniques (overset/chimera), performed at different model speeds, wavelengths, and wave heights using the commercial software Siemens PLM Star-CCM+. Instead, the analytical solution is obtained using nonlinear mathematical model. The presented non-linear mathematical model is developed using a combined approach based on 2D+T theory, momentum theory, and linear wake profile. Under such assumption, the double stepped planing hull is divided into three planing surfaces, and hydrodynamic forces acting on each planing surface is found by extension of simulation of symmetric water entry of two-dimensional wedge section bodies. Then, each sub-problem is solved by extending the mathematical simulation of wedge penetrating water. Final vertical force and pitching moment are found and substituted in motion equation. The mathematical model is able to compute heave and pitch motion in calm water and regular waves. Results of numerical method and novel 2D+T analytical method are compared against each other.
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| 4. |
- Ghadimi, P., et al.
(författare)
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Introducing a particular mathematicalmodel for predicting the resistance and performance of prismatic planing hulls in calm water by means of total pressure distribution
- 2015
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Ingår i: Journal of Naval Architecture and Marine Engineering. - : Department of Naval Architecture and Marine Engineering. - 1813-8535 .- 2070-8998. ; 12:2, s. 73-94
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Tidskriftsartikel (refereegranskat)abstract
- Mathematical modeling of planing hulls and determination of their characteristics are the most important subjects in hydrodynamic study of planing vessels. In this paper, a new mathematical model has been developed based on pressure distribution. This model has been provided for two different situations: (1) for a situation in which all forces pass through the center of gravity and (2) for a situation in which forces don not necessarily pass through the center of gravity. Two algorithms have been designed for the governing equations. Computational results have been presented in the form of trim angle, total pressure, hydrodynamic and hydrostatic lift coefficients, spray apex and total resistance which includes frictional, spray and induced resistances. Accuracy of the model has been verified by comparing the numerical findings against the results of Savitsky's method and available experimental data. Good accuracy is displayed. Furthermore, effects of deadrise angle on trim angle of the craft, position of spray apex and resistance have been investigated.
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| 5. |
- Lagali, Neil, et al.
(författare)
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Focused Tortuosity Definitions Based on Expert Clinical Assessment of Corneal Subbasal Nerves
- 2015
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Ingår i: Investigative Ophthalmology and Visual Science. - : ASSOC RESEARCH VISION OPHTHALMOLOGY INC. - 0146-0404 .- 1552-5783. ; 56:9, s. 5102-5109
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. We examined agreement among experts in the assessment of corneal subbasal nerve tortuosity. METHODS. Images of corneal subbasal nerves were obtained from investigators at seven sites (Auckland, Boston, Linkoping, Manchester, Oslo, Rostock, and Sydney) using laser-scanning in vivo confocal microscopy. A set of 30 images was assembled and ordered by increasing tortuosity by 10 expert graders from the seven sites. In a first experiment, graders assessed tortuosity without a specific definition and performed grading three times, with at least 1 week between sessions. In a second experiment, graders assessed the same image set using four focused tortuosity definitions. Intersession and intergrader repeatability for the experiments were determined using the Spearman rank correlation. RESULTS. Expert graders without a specific tortuosity definition had high intersession (Spearman correlation coefficient 0.80), but poor intergrader (0.62) repeatability. Specific definitions improved intergrader repeatability to 0.79. In particular, tortuosity defined by frequent small-amplitude directional changes (short range tortuosity) or by infrequent large-amplitude directional changes (long range tortuosity), indicated largely independent measures and resulted in improved repeatability across the graders. A further refinement, grading only the most tortuous nerve in a given image, improved the average correlation of a given graders ordering of images with the group average to 0.86 to 0.90. CONCLUSIONS. Definitions of tortuosity specifying short or long-range tortuosity and considering only the most tortuous nerve in an image improved the agreement in tortuosity grading among a group of expert observers. These definitions could improve accuracy and consistency in quantifying subbasal nerve tortuosity in clinical studies.
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