Search

Your search keyword '"Heyd, R."' showing total 189 results
Start Over Author "Heyd, R."
189 results on '"Heyd, R."'

2. The high-resolution imaging science experiment (HiRISE) in the MRO extended science phases (2009–2023)

Author

McEwen, A.S., Byrne, S., Hansen, C., Daubar, I.J., Sutton, S., Dundas, C.M., Bardabelias, N., Baugh, N., Bergstrom, J., Beyer, R., Block, K.M., Bray, V.J., Bridges, J.C., Chojnacki, M., Conway, S.J., Delamere, W.A., Ebben, T., Espinosa, A., Fennema, A., Grant, J., Gulick, V.C., Herkenhoff, K.E., Heyd, R., Leis, R., Ojha, L., Papendick, S., Schaller, C., Thomas, N., Tornabene, L.L., Weitz, C., and Wilson, S.A.

Published
2024
Full Text
View/download PDF

5. Optical properties of potential-inserted quantum wells in the near infrared and Terahertz ranges

Author

Raouafi, F., Samti, R., Benchamekh, R., Heyd, R., Boyer-Richard, S., Voisin, P., and Jancu, J-M.

Subjects
Condensed Matter - Materials Science
Abstract

We propose an engineering of the optical properties of GaAs/AlGaAs quantum wells using AlAs and InAs monolayer insertions. A quantitative study of the effects of the monolayer position and the well thickness on the interband and intersubband transitions, based on the extended-basis sp3d5s* tight-binding model, is presented. The effect of insertion on the interband transitions is compared with existing experimental data. As for intersubband transitions, we show that in a GaAs/AlGaAs quantum well including two AlAs and one InAs insertions, a three level {e1 , e2 , e3 } system where the transition energy e3-e2 is lower and the transition energy e2-e1 larger than the longitudinal optical phonon energy (36 meV) can be engineered together with a e3-e2 transition energy widely tunable through the TeraHertz range.

Published
2016
Full Text
View/download PDF

6. High precision comet trajectory estimates: the Mars flyby of C/2013 A1 (Siding Spring)

Author

Farnocchia, D., Chesley, S. R., Micheli, M., Delamere, A., Heyd, R. S., Tholen, D. J., Giorgini, J. D., Owen, W. M., and Tamppari, L. K.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The Mars flyby of C/2013 A1 (Siding Spring) represented a unique opportunity for imaging a long-period comet and resolving its nucleus and rotation period. Because of the small encounter distance and the high relative velocity, the goal of successfully observing C/2013 A1 from the Mars orbiting spacecrafts posed strict accuracy requirements on the comet's ephemerides. These requirements were hard to meet, as comets are known for being highly unpredictable: astrometric observations can be significantly biased and nongravitational perturbations affect comet trajectories. Therefore, even prior to the encounter, we remeasured a couple of hundred astrometric images obtained with ground-based and Earth-orbiting telescopes. We also observed the comet with the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera on 2014 October 7. In particular, these HiRISE observations were decisive in securing the trajectory and revealed that out-of-plane nongravitational perturbations were larger than previously assumed. Though the resulting ephemeris predictions for the Mars encounter allowed observations of the comet from the Mars orbiting spacecrafts, post-encounter observations show a discrepancy with the pre-encounter trajectory. We reconcile this discrepancy by employing the Rotating Jet Model, which is a higher fidelity model for nongravitational perturbations and provides an estimate of C/2013 A1's spin pole.

Published
2015
Full Text
View/download PDF

7. Novel quantitative methods to enable multispectral identification of high-purity water ice exposures on Mars using High Resolution Imaging Science Experiment (HiRISE) images

Author

Rangarajan, V.G., primary, Tornabene, L.L., additional, Osinski, G.R., additional, Dundas, C.M., additional, Beyer, R.A., additional, Herkenhoff, K.E., additional, Byrne, S., additional, Heyd, R., additional, Seelos, F.P., additional, Munaretto, G., additional, and Dapremont, A., additional

Published
2023
Full Text
View/download PDF

8. The high-resolution imaging science experiment (HiRISE) in the MRO extended science phases (2009–2023)

Author

McEwen, A.S., primary, Byrne, S., additional, Hansen, C., additional, Daubar, I.J., additional, Sutton, S., additional, Dundas, C.M., additional, Bardabelias, N., additional, Baugh, N., additional, Bergstrom, J., additional, Beyer, R., additional, Block, K.M., additional, Bray, V.J., additional, Bridges, J.C., additional, Chojnacki, M., additional, Conway, S.J., additional, Delamere, W.A., additional, Ebben, T., additional, Espinosa, A., additional, Fennema, A., additional, Grant, J., additional, Gulick, V.C., additional, Herkenhoff, K.E., additional, Heyd, R., additional, Leis, R., additional, Ojha, L., additional, Papendick, S., additional, Schaller, C., additional, Thomas, N., additional, Tornabene, L.L., additional, Weitz, C., additional, and Wilson, S.A., additional

Published
2023
Full Text
View/download PDF

9. Fracture-Related Infection Epidemiology, Etiology, Diagnosis, Prevention, and Treatment.

Author

Rupp, M., Walter, N., Bärtl, S., Heyd, R., Hitzenbichler, F., and Alt, V.

Abstract

Background: Fracture-related infection (FRI) is a challenge to physicians and other workers in health care. In 2018, there were 7253 listed cases of FRI in Germany, corresponding to an incidence of 10.7 cases per 100 000 persons per year. Methods: This review is based on pertinent publications retrieved from a search in PubMed with the search terms "fracture," "infection," "guideline," and "consensus." Aside from the primary literature, international guidelines and consensus recommendations were evaluated as well. Results: FRI arise mainly from bacterial contamination of the fracture site. Staphylococcus aureus is the most commonly detected pathogen. The treatment is based on surgery and antibiotics and should be agreed upon by an interdisciplinary team; it is often difficult because of biofilm formation. Treatment options include implant -preserving procedures and single-stage, two-stage, or multi-stage implant replacement. Treatment failure occurs in 10.3% to 21.4% of cases. The available evidence on the efficacy of various treatment approaches is derived mainly from retrospective cohort studies (level III evidence). Therefore, periprosthetic joint infections and FRI are often discussed together. Conclusion: FRI presents an increasing challenge. Preventive measures should be optimized, and the treatment should always be decided upon by an interdisciplinary team. Only low-level evidence is available to date to guide diagnostic and treatment decisions. High-quality studies are therefore needed to help us meet this challenge more effectively. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

10. Modeling and simulation of complex flows using Basset digital filters

Author

Lahboub D., Bakak A., Lotfi M., Heyd R., and Koumina A.

Subjects
Environmental sciences, GE1-350
Abstract

Taking into account the Basset force (memory term), in the balance of the forces exerted on a colloidal particle (CP) suspended in a fluid, results in an equation of motion of integrodifferential form. This type of equation allows for example to modeling a colloidal particle settling in an quiescent fluid or in a fluid flowing at low particle’s Reynolds number. It also allows to study the transport of pathogens via aerosols, thus giving access to important information on the airborne propagation of respiratory viruses, such as COVID-19 and its variants for example. Most studies of the PCs motion in a fluid are usually simplified by not taking into account the Basset memory force, as it considerably complicates the numerical solution of the equations of motion of these PCs. This simplification can lead to considerable errors in the evaluation of the trajectory and velocity of the PCs, which can subsequently lead to errors in the calculation of the physical and rheological properties of colloidal suspensions. The present study deals with the numerical solution of Basset’s integro-differential equation, by two significantly different approaches, namely : a piecewise linear approximation (PLA) and the method of Basset numerical filters (BNF). These methods are first exposed and compared on test cases, they are then applied to the study of the sedimentation of spherical PCs with micrometer radii. This study has shown that the usual dynamics of PCs, which does not take into account the Basset memory term, can be very different from the exact dynamics using the Basset force. The BNF approach is finally applied to the study of the motion of PCs driven by flows through complex geometries (pipes, porous media, …).

Published
2021
Full Text
View/download PDF

11. Correcting spacecraft jitter in HiRISE images

Author

Sutton, S. S., primary, Boyd, A. K., additional, Kirk, R. L., additional, Cook, D., additional, Backer, J. W., additional, Fennema, A., additional, Heyd, R., additional, McEwen, A. S., additional, and Mirchandani, S. D., additional

Published
2018
Full Text
View/download PDF

14. Revealing Active Mars with HiRISE Digital Terrain Models and Orthoimages

Author

Sutton, S, Chojnacki, M, Mcewen, A, Kirk, R, Dundas, C, Schaefer, E, Conway, Susan J., Diniega, S, Portyankina, G, Landis, M, Baugh, N, Heyd, R, Byrne, S, Tornabene, L, Ojha, L, Hamilton, C, and Conway, Susan

Subjects
[SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology
Published
2022

16. CaSSIS: Overview of Imaging in the First 9 Months of the Prime Mission

Author

Thomas, Nicolas, Cremonese, Gabriele, Al-Meida, M, Banaszkiewicz, M., Bapst, J, Becerra, P, Bridges, J., Byrne, S., Conway, S., da Deppo, V., Debei, S., El-Maarry, M, Fennema, A, Hauber, E., Heyd, R., Hansen, C, Ivanov, A., Keszthelyi, L, Kirk, R, Kuzmin, R, Lucchetti, A, Mangold, N, Marriner, C, Marinangeli, L, Massironi, M, Mcewen, A, Okubo, C, Orleanski, P, Pajola, M, Bowen, A, Patel, M, Perry, J, Pommerol, A, Pozzobon, R, Read, M, Tesson, P.-A, Tornabene, L, Tulyakov, S, Wajer, P, Witek, P, Wray, J, Ziethe, R, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Space Research Centre [Leicester], University of Leicester, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Conway, Susan

Subjects
Planetengeologie, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Mars, CaSSIS, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology, Camera, ComputingMilieux_MISCELLANEOUS, ExoMars, Imaging
Abstract

International audience

Published
2019

20. CaSSIS - Targeting, Operations, and Data Reduction

Author

Thomas, Nicolas, Cremonese, G., Miguel, Almeida, Backer, J., Becerra Valdes, Patricio, Borrini, Gaetano, Byrne, S., Gruber, Mario, Gubler, Pascal Elias, Heyd, R., Ivanov, A., Keszthelyi, L., Marriner, C., McArthur, G., McEwen, A.S., Okubo, C., Patel, M.R., Pommerol, Antoine, Re, C., Schaller, C., Scheidt, S., Simioni, E., Sutton, S., Tulyakov, S., and Zimmermann, Claudio

Subjects
530 Physics, 520 Astronomy, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 620 Engineering
Abstract

CaSSIS (Colour and Stereo Surface Imaging System) is the main imaging system for the ExoMars Trace Gas Orbiter (TGO) mission. A scientifically compelling instrument was completed in October 2015 and launched in March 2016 [1]. This abstract describes the targeting, operations, and data reduction pipelines used to produce calibrated observations of selected targets.

Published
2018
Full Text
View/download PDF

21. Erratum zu: Strahlentherapie und Onkologie, Volume 186 (No. 1)

Author

Dittmann, K., Mayer, C., Rodemann, H. P., Mücke, R., Seegenschmiedt, M. H., Heyd, R., Schäfer, U., Prott, F-J, Glatzel, M., Micke, O., Adamietz, B., Schulz-Wendtland, R., Alibek, S., Uder, M., Sauer, R., Ott, O., Keilholz, L., Heyd, R., Dorn, A.P., Herkströter, M., Rödel, C., Müller-Schimpfle, M., Fraunholz, I., Wolff, H.A., Gaedcke, J., Jung, K., Hermann, R.M., Rothe, H., Schirmer, M., Liersch, T., Herrmann, M.K.A., Hennies, S., Rave-Fränk, M., Hess, C.F., Christiansen, H., Mizumoto, M., Nakayama, H., Tokita, M., Sugahara, S., Hashii, H., Sakae, T., Tsuboi, K., Sakurai, H., Tokuuye, K., Geinitz, H., Thamm, R., Scholz, C., Heinrich, C., Prause, N., Kerndl, S., Keller, M., Busch, R., Molls, M., and Zimmermann, F.B.

Published
2010
Full Text
View/download PDF

22. Isothermal dehydration of thin films of water and sugar solutions.

Author

Heyd, R., Rampino, A., Bellich, B., Elisei, E., Cesàro, A., and Saboungi, M.-L.

Subjects
*THIN films, *DEHYDRATION reactions, *GLUCOSE, *THERMODYNAMICS, *DIFFUSION, *COMPUTER simulation
Abstract

The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose web of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules. [ABSTRACT FROM AUTHOR]

Published
2014
Full Text
View/download PDF

26. CORRECTING SPACECRAFT JITTER IN HIRISE IMAGES

Author

Sutton, S. S., primary, Boyd, A. K., additional, Kirk, R. L., additional, Cook, D., additional, Backer, J. W., additional, Fennema, A., additional, Heyd, R., additional, McEwen, A. S., additional, and Mirchandani, S. D., additional

Published
2017
Full Text
View/download PDF

28. Radiotherapy in langerhans cell histiocytosis : a rare indication in a rare disease

Author

Kriz, J. (Jan), Eich, H. (Hans-Theodor), Bruns, F. (Frank), Heyd, R. (Reinhard), Schäfer, U. (Ulrich), Haverkamp, U. (Uwe), Büntzel, J. (Jens), Seegenschmiedt, M.H. (Michael), Micke, O. (Oliver), and Universitäts- und Landesbibliothek Münster

Subjects
Adult, Male, Adolescent, Langerhans cell histiocytosis, Radiotherapy, Benign disorder, Effectivity, Rare disease, Kaplan-Meier Estimate, Disease-Free Survival, Young Adult, Humans, ddc:610, Child, Aged, Retrospective Studies, Aged, 80 and over, Research, Radiotherapy Dosage, Middle Aged, Histiocytosis, Langerhans-Cell, Treatment Outcome, Oncology, Radiology Nuclear Medicine and imaging, Medicine and health, Female
Abstract

Introduction: Langerhans Cell Histiocytosis (LCH) represents a rare benign disorder, previously designated as “Histiocytosis X”, “Type II Histiocytosis” or “Langerhans Cell Granulomatosis”. Clinical presentation includes osteolysis, ulcerations of skin and soft tissues but also involvement of the CNS is described. Because treatment concepts are not well defined the German Cooperative Group on Radiotherapy for Benign Diseases performed a retrospective analysis. Methods and material: Eight closely cooperating centres collected patients’ data of the past 45 years. As study endpoints disease free survival, recurrent disease, death and therapy related side effects were defined. Results: A total of 80 patients with histologically proven LCH were irradiated within the past 45 years. According to the LCH classification of Greenberger et al. 37 patients had stage Ia, 21 patients stage Ib, 13 patients stage II and 9 patients stage IIIb and the median age was 29 years. The median Follow up was 54 months (range 9–134 months). A total of 39 patients had a surgical intervention and 23 patients a chemotherapy regimen. Radiation treatment was carried out with a median total dose of 15 Gy (range 3–50.4 Gy). The median single fraction was 2 Gy (range 1.8-3 Gy). Overall, 77% patients achieved a complete remission and 12.5% achieved a partial remission. The long-term control rate reached 80%. Within an actuarial overall 5-year survival of 90% no radiogenic side and late effects ≥EORTC/RTOG II° were observed. Conclusion: In the present study a large collective of irradiated patients was analysed. Radiotherapy (RT) is a very effective and safe treatment option and even low RT doses show sufficient local control.

Published
2013

29. Gamma Knife radiosurgery of benign petroclival and cavernous sinus meningiomas: results of a single institution retrospective analysis based on a prospective data base of more than 10-years

Author

Wolff, R., Heyd, R., Rödel, C., and Seifert, V.

Subjects
Skull Base, ddc: 610, Meningeom, Schädelbasis, 610 Medical sciences, Medicine, Meningioma, Radiosurgery, Radiochirurgie
Abstract

Objective: Single fraction stereotactic Gamma Knife radiosurgery (GKRS) is an established treatment option in the management of skull base meningiomas. This study aims at local control, clinical symptomatology, as well as early or late toxicity related to GKRS according to Common Terminology Criteria[for full text, please go to the a.m. URL], 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS)

Published
2012

31. [Immunoglobulin for prevention of radiogenic mucositis]

Author

Mose S, Irenaeus Adamietz, Thilmann C, Saran F, Heyd R, Knecht R, and Hd, Böttcher

Subjects
Adult, Male, Radiation-Sensitizing Agents, Stomatitis, Neoplasm, Residual, Immunization, Passive, Mouth Mucosa, Radiotherapy Dosage, Middle Aged, Combined Modality Therapy, Injections, Intramuscular, Carboplatin, Treatment Outcome, Head and Neck Neoplasms, Humans, Female, Radiotherapy, Adjuvant, Radiation Injuries, Aged
Abstract

Among various therapies administered during radiation-induced mucositis, treatment with immunoglobulin has proven clinically successful. In this study the efficacy of prophylactic applications of immunoglobulin was investigated from January 1992 through August 1993. Forty-two patients with histologically-proven head and neck cancer were given postoperative radiation treatment. In cases with macroscopic tumor residues or inoperability, combined radio-chemotherapy was given. This included 51.3 Gy at 1.9 Gy 5x/week, boosted to 10-26 Gy at 2 Gy 5x/week and carboplatin 60 mg/m2 at days 1-5 and 29-33. Panthenol (4x10 ml/day) and nystatin (4 x 1 ml/day) were given to 20 patients as prophylactic treatment for mucositis. Twenty-two subsequent patients also received intramuscular 800 mg (5 ml) human immunoglobulin (1x/week). According to the Seegenschmiedt/Sauer classification the extent of mucositis was determined 3x/week. Comparison of the distribution of maximal mucositis revealed a slightly more severe mucosal reaction in the control group (n.s.). Analysis of the mean degree of mucositis in both groups demonstrated statistically significant differences (p = 0.031) related to the whole collective and patients receiving concomitant chemotherapy while no effect of immunoglobulin was found in patients treated by radiation alone. In the immunoglobulin-treated-group, the time from the beginning of therapy to the first interruption was prolonged 5 days (37.5 +/- 13.1 vs. 42.7 +/- 13.3 days), but this difference was not significant. Although prophylactic application of immunoglobulin seemed to lower the degree of radiation-induced mucositis, this effect was less significant when compared to the immunoglobulin given in a therapeutic manner.

Published
1995

33. Erratum to: Strahlentherapie und Onkologie, Volume 186 (No. 1)

Author

Dittmann, K., primary, Mayer, C., additional, Rodemann, H. P., additional, Mücke, R., additional, Seegenschmiedt, M. H., additional, Heyd, R., additional, Schäfer, U., additional, Prott, F-J, additional, Glatzel, M., additional, Micke, O., additional, Adamietz, B., additional, Schulz-Wendtland, R., additional, Alibek, S., additional, Uder, M., additional, Sauer, R., additional, Ott, O., additional, Keilholz, L., additional, Dorn, A.P., additional, Herkströter, M., additional, Rödel, C., additional, Müller-Schimpfle, M., additional, Fraunholz, I., additional, Wolff, H.A., additional, Gaedcke, J., additional, Jung, K., additional, Hermann, R.M., additional, Rothe, H., additional, Schirmer, M., additional, Liersch, T., additional, Herrmann, M.K.A., additional, Hennies, S., additional, Rave-Fränk, M., additional, Hess, C.F., additional, Christiansen, H., additional, Mizumoto, M., additional, Nakayama, H., additional, Tokita, M., additional, Sugahara, S., additional, Hashii, H., additional, Sakae, T., additional, Tsuboi, K., additional, Sakurai, H., additional, Tokuuye, K., additional, Geinitz, H., additional, Thamm, R., additional, Scholz, C., additional, Heinrich, C., additional, Prause, N., additional, Kerndl, S., additional, Keller, M., additional, Busch, R., additional, Molls, M., additional, and Zimmermann, F.B., additional

Published
2010
Full Text
View/download PDF

41. 181 New 3D interstitial HDR brachytherapy technique combined with 3D external beam radiotherapy and androgen deprivation for localized prostate cancer: Preliminary results

Author

Martin, T., primary, Hey-Koch, S., additional, Strassmann, G., additional, Kolotas, C., additional, Rogge, B., additional, Heyd, R., additional, Dannenberg, T., additional, Kurek, R., additional, Baltas, D., additional, Tunn, U.W., additional, and Zamboglou, N., additional

Published
2000
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results