TY  - JOUR
A1  - Bhattarai, Aroj
A1  - May, Charlotte Anabell
A1  - Staat, Manfred
A1  - Kowalczyk, Wojciech
A1  - Tran, Thanh Ngoc
T1  - Layer-specific damage modeling of porcine large intestine under biaxial tension
JF  - Bioengineering
N2  - The mechanical behavior of the large intestine beyond the ultimate stress has never been investigated. Stretching beyond the ultimate stress may drastically impair the tissue microstructure, which consequently weakens its healthy state functions of absorption, temporary storage, and transportation for defecation. Due to closely similar microstructure and function with humans, biaxial tensile experiments on the porcine large intestine have been performed in this study. In this paper, we report hyperelastic characterization of the large intestine based on experiments in 102 specimens. We also report the theoretical analysis of the experimental results, including an exponential damage evolution function. The fracture energies and the threshold stresses are set as damage material parameters for the longitudinal muscular, the circumferential muscular and the submucosal collagenous layers. A biaxial tensile simulation of a linear brick element has been performed to validate the applicability of the estimated material parameters. The model successfully simulates the biomechanical response of the large intestine under physiological and non-physiological loads.
KW  - biaxial tensile experiment
KW  - anisotropy
KW  - hyperelastic
KW  - constitutive modeling
KW  - damage
Y1  - 2022
U6  - http://dx.doi.org/10.3390/bioengineering9100528
SN  - 2306-5354
N1  - Der Artikel gehört zum Sonderheft "Computational Biomechanics"
VL  - 9
IS  - 10, Early Access
SP  - 1
EP  - 17
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Bhattarai, Aroj
A1  - Staat, Manfred
T1  - Modelling of Soft Connective Tissues to Investigate Female Pelvic Floor Dysfunctions
JF  - Computational and Mathematical Methods in Medicine
N2  - After menopause, decreased levels of estrogen and progesterone remodel the collagen of the soft tissues thereby reducing their stiffness. Stress urinary incontinence is associated with involuntary urine leakage due to pathological movement of the pelvic organs resulting from lax suspension system, fasciae, and ligaments. This study compares the changes in the orientation and position of the female pelvic organs due to weakened fasciae, ligaments, and their combined laxity. A mixture theory weighted by respective volume fraction of elastin-collagen fibre compound (5%), adipose tissue (85%), and smooth muscle (5%) is adopted to characterize the mechanical behaviour of the fascia. The load carrying response (other than the functional response to the pelvic organs) of each fascia component, pelvic organs, muscles, and ligaments are assumed to be isotropic, hyperelastic, and incompressible. Finite element simulations are conducted during Valsalva manoeuvre with weakened tissues modelled by reduced tissue stiffness. A significant dislocation of the urethrovesical junction is observed due to weakness of the fascia (13.89 mm) compared to the ligaments (5.47 mm). The dynamics of the pelvic floor observed in this study during Valsalva manoeuvre is associated with urethral-bladder hypermobility, greater levator plate angulation, and positive Q-tip test which are observed in incontinent females.
Y1  - 2018
U6  - http://dx.doi.org/10.1155/2018/9518076
SN  - 1748-6718
VL  - 2018
IS  - Article ID 9518076
SP  - 1
EP  - 16
PB  - Hindawi
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Bhattarai, Aroj
A1  - Staat, Manfred
T1  - Computational comparison of different textile implants to correct apical prolapse in females
JF  - Current Directions in Biomedical Engineering
N2  - Prosthetic textile implants of different shapes, sizes and polymers are used to correct the apical prolapse after hysterectomy (removal of the uterus). The selection of the implant before or during minimally invasive surgery depends on the patient’s anatomical defect, intended function after reconstruction and most importantly the surgeon’s preference. Weakness or damage of the supporting tissues during childbirth, menopause or previous pelvic surgeries may put females in higher risk of prolapse. Numerical simulations of reconstructed pelvic floor with weakened tissues and organ supported by textile product models: DynaMesh®-PRS soft, DynaMesh®-PRP soft and DynaMesh®-CESA from FEG Textiletechnik mbH, Germany are compared.
Y1  - 2018
U6  - http://dx.doi.org/10.1515/cdbme-2018-0159
VL  - 4
IS  - 1
SP  - 661
EP  - 664
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Bhattarai, Aroj
A1  - Staat, Manfred
T1  - A computational study of organ relocation after laparoscopic pectopexy to repair posthysterectomy vaginal vault prolapse
JF  - Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization
Y1  - 2019
U6  - http://dx.doi.org/10.1080/21681163.2019.1670095
SN  - 2168-1171
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Birgel, Stefan
A1  - Leschinger, Tim
A1  - Wegmann, Kilian
A1  - Staat, Manfred
T1  - Calculation of muscle forces and joint reaction loads in the shoulder area via an OpenSim based computer model
JF  - tm - Technisches Messen
N2  - Using the OpenSim software and verified anatomical data, a computer model for the calculation of biomechanical parameters is developed and used to determine the effect of a reattachment of the Supraspinatus muscle with a medial displacement of the muscle attachment point, which may be necessary for a rupture of the supraspinatus tendon. The results include the influence of the operation on basic biomechanical parameters such as the lever arm, as well as the calculated the muscle activations for the supraspinatus and deltoid. In addition, the influence on joint stability is examined by an analysis of the joint reaction force. The study provides a detailed description of the used model, as well as medical findings to a reattachment of the supraspinatus.

Mit der Software OpenSim und überprüften anatomischen Daten wird ein Computermodell zur Berechnung von biomechanischen Parametern entwickelt und genutzt, um den Effekt einer Refixierung des Supraspinatusmuskels mit einer medialen Verschiebung des Muskelansatzpunktes zu ermitteln, wie sie unter anderem nach einem Riss der Supraspinatussehne notwendig sein kann. Die Ergebnisse umfassen hierbei den Einfluss der Operation auf grundlegende biomechanische Parameter wie den Hebelarm sowie die berechneten Muskelaktivierungen für den Supraspinatus und Deltoideus. Zusätzlich wird der Einfluss auf die Gelenkstabilität betrachtet und durch eine Analyse der Gelenkreaktionskraft untersucht. Die Studie bietet eine detaillierte Beschreibung des genutzten Modells, sowie medizinische Erkenntnisse zu einer Refixierung des Supraspinatus.
Y1  - 2018
U6  - http://dx.doi.org/10.1515/teme-2017-0114
SN  - 2196-7113
VL  - 85
IS  - 5
SP  - 321
EP  - 330
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Blome, Hans-Joachim
A1  - Seboldt, Wolfgang
A1  - Dachwald, Bernd
A1  - Richter, Lutz
T1  - Proposal for an integrated European Space Exploration Study
JF  - Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch
Y1  - 2004
SN  - 0-87703-523-7
N1  - Proceedings IAC-2004-IAA, 3.6.1.06; Space Debris and Space Traffic Management Symposium <2004, Vancouver, British Columbia> ; International Academy of Astronautics
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - JOUR
A1  - Brockhaus, Moritz K.
A1  - Behbahani, Mehdi
A1  - Muris, Farina
A1  - Jansen, Sebastian V.
A1  - Schmitz- Rode, Thomas
A1  - Steinseifer, Ulrich
A1  - Clauser, Johanna C.
T1  - In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept
JF  - Artificial Organs
N2  - Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.
Y1  - 2021
U6  - http://dx.doi.org/10.1111/aor.14046
SN  - 1525-1594
VL  - 45
IS  - 12
SP  - 1513
EP  - 1521
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Burkhardt, Klaus
A1  - Schwarz, Sonja
A1  - Pan, Chengrui
A1  - Stelter, Felix
A1  - Kotliar, Konstantin
A1  - Eynatten, Maxilian von
A1  - Sollinger, Daniel
A1  - Lanzl, Ines
A1  - Heemann, Uwe
A1  - Baumann, Marcus
T1  - Myeloid-related protein 8/14 complex describes microcirculatory alterations in patients with type 2 diabetes and nephropathy
JF  - Cardiovascular Diabetology
Y1  - 2009
SN  - 1475-2840
VL  - 8
IS  - 10
SP  - 1
EP  - 8
PB  - -
ER  - 
TY  - JOUR
A1  - Campen, R.
A1  - Kowalski, Julia
A1  - Lyons, W.B.
A1  - Tulaczyk, S.
A1  - Dachwald, Bernd
A1  - Pettit, E.
A1  - Welch, K. A.
A1  - Mikucki, J.A.
T1  - Microbial diversity of an Antarctic subglacial community and high‐resolution replicate sampling inform hydrological connectivity in a polar desert
JF  - Environmental Microbiology
Y1  - 2019
U6  - http://dx.doi.org/10.1111/1462-2920.14607
SN  - 1462-2920
IS  - accepted article
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Capri, Miriam
A1  - Morsiani, Cristina
A1  - Santoro, Aurelia
A1  - Moriggi, Manuela
A1  - Conte, Maria
A1  - Martucci, Morena
A1  - Bellavista, Elena
A1  - Fabbri, Cristina
A1  - Giampieri, Enrico
A1  - Albracht, Kirsten
A1  - Flück, Martin
A1  - Ruoss, Severin
A1  - Brocca, Lorenza
A1  - Canepari, Monica
A1  - Longa, Emanuela
A1  - Giulio, Irene Di
A1  - Bottinelli, Roberto
A1  - Cerretelli, Paolo
A1  - Salvioli, Stefano
A1  - Gelfi, Cecilia
A1  - Franceschi, Claudio
A1  - Narici, Marco
A1  - Rittweger, Jörn
T1  - Recovery from 6-month spaceflight at the International Space Station: muscle-related stress into a proinflammatory setting
JF  - The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Y1  - 2019
U6  - http://dx.doi.org/10.1096/fj.201801625R
VL  - 33
IS  - 4
SP  - 5168
EP  - 5180
ER  - 
TY  - JOUR
A1  - Cehreli, Ruksan
A1  - Akpinar, Hale
A1  - Temiz Artmann, Aysegül
A1  - Sagol, Ozgul
T1  - Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis
JF  - Gastroenterology Research
Y1  - 2015
U6  - http://dx.doi.org/10.14740/gr683w
SN  - 1918-2813
VL  - 8
IS  - 5
SP  - 265
EP  - 273
ER  - 
TY  - JOUR
A1  - Chloé, Radermacher
A1  - Malyaran, Hanna
A1  - Craveiro, Rogerio Bastos
A1  - Peglow, Sarah
A1  - Behbahani, Mehdi
A1  - Pufe, Thomas
A1  - Wolf, Michael
A1  - Neuss, Sabine
T1  - Mechanical loading on cementoblasts: a mini review
JF  - Osteologie
N2  - Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments.
KW  - Cementoblast
KW  - Compression
KW  - Tension
KW  - Mechanotransduction
KW  - Forces
Y1  - 2022
U6  - http://dx.doi.org/10.1055/a-1826-0777
SN  - 1019-1291
VL  - 31
IS  - 2
SP  - 111
EP  - 118
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Ciobanu, Octavian
A1  - Staat, Manfred
A1  - Rahimi, Alireza
T1  - The use of open source software in biomechanical finite element analysis
JF  - Buletinul Institutului Politehnic din Iaşi / Universitatea Tehnică Gh. Asachi, Iaşi Secţia 5, Construcţii de maşini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta
Y1  - 2008
SN  - 1011-2855
VL  - 54
IS  - 7/8
SP  - 213
EP  - 220
ER  - 
TY  - JOUR
A1  - Ciritsis, Alexander
A1  - Horbach, Andreas
A1  - Staat, Manfred
A1  - Kuhl, Christiane K.
A1  - Kraemer, Nils Andreas
T1  - Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo
JF  - Journal of Biomedical Materials Research: Part B:  Applied Biomaterials
N2  - Purpose
In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model.

Material and Methods
Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio).

Results
In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4% for TPU and of 1.2% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF.

Conclusion
The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827–833, 2018.
Y1  - 2018
U6  - http://dx.doi.org/10.1002/jbm.b.33877
SN  - 1552-4981
VL  - 106
IS  - 2
SP  - 827
EP  - 833
PB  - Wiley
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Colombo, Daniele
A1  - Drira, Slah
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - An element-based formulation for ES-FEM and FS-FEM models for implementation in standard solid mechanics finite element codes for 2D and 3D static analysis
JF  - International Journal for Numerical Methods in Engineering
N2  - Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element.
KW  - distorted element
KW  - ES-FEM
KW  - FS-FEM
KW  - non-simplex S-FEM elements
KW  - S-FEM
Y1  - 2022
U6  - http://dx.doi.org/10.1002/nme.7126
SN  - 1097-0207
VL  - 124
IS  - 2
SP  - 402
EP  - 433
PB  - Wiley
CY  - Chichester
ER  - 
TY  - JOUR
A1  - Conzen, Catharina
A1  - Albanna, Walid
A1  - Weiss, Miriam
A1  - Kürten, David
A1  - Vilser, Walthard
A1  - Kotliar, Konstantin
A1  - Zäske, Charlotte
A1  - Clusmann, Hans
A1  - Schubert, Gerrit Alexander
T1  - Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes
JF  - Translational Stroke Research
N2  - Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5–14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome.
Y1  - 2018
U6  - http://dx.doi.org/10.1007/s12975-017-0585-8
SN  - 1868-601X
IS  - 9
SP  - 284
EP  - 293
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of very-low-thrust trajectories using evolutionary neurocontrol
JF  - Acta Astronautica. 57 (2005), H. 2-8
Y1  - 2005
SN  - 0094-5765
SP  - 175
EP  - 185
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Minimum Transfer Times for Nonperfectly Reflecting Solar Sailcraft
JF  - Journal of Spacecraft and Rockets. 41 (2004), H. 4
Y1  - 2004
SN  - 0022-4650
N1  - 2. ISSN: 1533-6794
SP  - 693
EP  - 695
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimal Solar Sail Trajectories for Missions to the Outer Solar System
JF  - Journal of guidance, control, and dynamics. 28 (2005), H. 6
Y1  - 2005
SN  - 0162-3192
N1  - 2. ISSN: 0162-3192. - 3. ISSN: 0731-5090
SP  - 1187
EP  - 1193
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of Interplanetary Solar Sailcraft Trajectories Using Evolutionary Neurocontrol
JF  - Journal of guidance, control, and dynamics. 27 (2004), H. 1
Y1  - 2004
SN  - 0162-3192
N1  - 2. ISSN: 0162-3192. - 3. ISSN: 0731-5090
SP  - 66
EP  - 72
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Interplanetary Mission Analysis for Non-Perfectly Reflecting Solar Sailcraft Using Evolutionary Neurocontrol
JF  - Astrodynamics 2003 : proceedings of the AAS/AIAA Astrodynamics Conference held August 3 - 7, 2003, Big Sky, Montana / ed. by Jean de Lafontaine. - Pt. 2. - (Advances in the astronautical sciences ; 116,2)
Y1  - 2004
SN  - 0-87703-509-1
N1  - Astrodynamics Conference <2003, Big Sky, Mont.> ; American Institute of Aeronautics and Astronautics <Reston, Va.> ; AAS-03-579
SP  - 1247
EP  - 1262
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Verwendung eines neuronalen Reglers und evolutionärer Algorithmen zur Berechnung optimaler interplanetarer Sonnenseglerbahnen
JF  - Deutscher Luft- und Raumfahrtkongress 2003 : München, 17. bis 20. November 2003, Motto: 100 Jahre Motorflug - 112 Jahre Menschenflug: Visionen gestalten Zukunft / Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 1. - (Jahrbuch ... der Deutschen Gesellschaft für Luft- und Raumfahrt)
Y1  - 2003
N1  - Deutscher Luft- und Raumfahrt-Kongreß <2003, München> ; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth ; DGLR-2002-089
SP  - 211
EP  - 218
CY  - Bonn
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Low-Thrust Trajectory Optimization and Interplanetary Mission Analysis Using Evolutionary Neurocontrol
JF  - Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Brücke für eine wissensbasierte Gesellschaft / Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft für Luft- und Raumfahrt)
Y1  - 2004
N1  - Deutscher Luft- und Raumfahrt-Kongress <2004, Dresden> ; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth ; DGLR-2004-116
SP  - 917
EP  - 926
CY  - Bonn
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Evolutionary Neurocontrol: A Smart Method for Global Optimization of Low-Thrust Trajectories
JF  - 22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)
Y1  - 2004
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; AIAA/AAS Astrodynamics Specialist Conference and Exhibit <2004, Providence, RI> ; AIAA paper number: AIAA-2004-5405
PB  - American Inst. of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimal Solar Sail Trajectories for Missions to the Outer Solar System
JF  - 22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)
Y1  - 2004
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; AIAA/AAS Astrodynamics Specialist Conference and Exhibit <2004, Providence, RI> ; AIAA paper number: AIAA-2004-5406
PB  - American Inst. of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of very-low-thrust trajectories using evolutionary neurocontrol
JF  - Acta Astronautica
N2  - Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric).
Y1  - 2005
SN  - 1879-2030
VL  - 57
IS  - 2-8
SP  - 175
EP  - 185
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ball, Andrew J.
A1  - Ulamec, Stephan
A1  - Price, Michael E.
T1  - A small mission for in situ exploration of a primitive binary near-Earth asteroid  / Ball, Andrew J. ; Ulamec, Stephan ; Dachwald, Bernd ; Price, Michael E. ; [u.a.]
JF  - Advances in Space Research. 43 (2009), H. 2
Y1  - 2009
SN  - 0273-1177
SP  - 317
EP  - 324
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Baturkin, Volodymyr
A1  - Coverstone, Victoria L.
A1  - Dietrich, Benjamin
A1  - Garbe, Gregory P.
A1  - Görlich, Marianne
A1  - Leipold, Manfred
A1  - Lura, Franz
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R.
A1  - Mengali, Giovanni
A1  - Quatra, Alessandro A.
A1  - Rios-Reyes, Leonel
A1  - Scheeres, Daniel J.
A1  - Seboldt, Wolfgang
A1  - Wie, Bong
T1  - Potential Effects of Optical Solar Sail Degradation on Interplanetary Trajectory Design
JF  - Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)
Y1  - 2006
UR  - http://www.spacesailing.net/paper/200508_LakeTahoe_Dachwald+.pdf
SN  - 0-87703-527-X
N1  - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-413
SP  - 2569
EP  - 2592
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Low-Thrust Gravity Assist Trajectory Optimization Using Evolutionary Neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile ...
JF  - Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)
Y1  - 2006
SN  - 0-87703-527-X
N1  - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-374
SP  - 1911
EP  - 1928
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile
JF  - IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore
Y1  - 2007
SN  - 978-1-424-41339-3
N1  - ISBN 10: 1-424-41339-7 ; IEEE Congress on Evolutionary Computation <2007, Singapore> ; 	Institute of Electrical and Electronics Engineers ; Nebent: CEC 2007 ; Parallel als Online-Ausg. erschienen
SP  - 965
EP  - 972
PB  - IEEE Service Center
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Evolutionary Neurocontrol as a Novel Method for Low-Thrust Gravity Assist Trajectory Optimization / I. Carnelli ; B. Dachwald ; M. Vasile
JF  - Proceedings of the Twenty-Fifth International Symposium on Space Technology and Science (Selected papers) : Kanazawa, [June 4 through June 11, 2006, at Kanazawa-shi Kanko Kaikan in Kanazawa city] / [Japan Society for Aeronautical and Space Sciences. Kohtaro Matsumoto [ed.-in-chief]
Y1  - 2006
SN  - 4-99005-002-9
N1  - International Symposium on Space Technology and Science <25, 2006, Kanazawa> ; ISTS 2006-d-46
SP  - 569
EP  - 574
PB  - JSASS
CY  - Tokyo
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, Ian
A1  - Vasile, Massimiliano
T1  - Evolutionary Neurocontrol: A Novel Method for Low-Thrust Gravity-Assist Trajectory Optimization / Carnelli, Ian ; Dachwald, Bernd ; Vasile, Massimiliano
JF  - Journal of guidance control and dynamics. 32 (2009), H. 2
Y1  - 2009
SN  - 0731-5090
SP  - 616
EP  - 625
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Kahle, Ralph
A1  - Wie, Bong
T1  - Solar Sailing Kinetic Energy Impactor (KEI) Mission Design Tradeoffs for Impacting and Deflecting Asteroid 99942 Apophis
JF  - AIAA Guidance, Navigation, and Control Conference & Exhibit - AIAA Atmospheric Flight Mechanics Conference & Exhibit - AIAA Modeling and Simulation Technologies Conference & Exhibit - AIAA/AAS Astrodynamics Specialist Conference & Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )
Y1  - 2006
SN  - 1-56347-802-1
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; American Astronautical Society ; AIAA/AAS Astrodynamics Specialist Conference & Exhibit <2006,  Keystone, Colo.> ; AIAA paper number: AIAA-2006-6178
SP  - 1
EP  - 20
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Leipold, M.
A1  - Fichtner, H.
T1  - Heliopause Explorer - A Sailcraft Mission to the Outer Boundaries of the Solar System / M. Leipold ; H. Fichtner ; B. Heber  ... B. Dachwald ...
JF  - Proceedings of the Fifth IAA International Conference on Low Cost Planetary Missions : 24 - 26 September 2003, ESTEC, Noordwijk, the Netherlands / [comp. by R. A. Harris]
Y1  - 2003
SN  - 92-9092-853-0
N1  - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; International Academy of Astronautics ; European Space Research and Technology Centre
SP  - 367
EP  - 375
PB  - ESA
CY  - Noordwijk
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - MacDonald, Malcolm
A1  - McInnes, Colin R.
T1  - Heliocentric Solar Sail Orbit Transfers with Locally Optimal Control Laws / Malcolm Macdonald ; Colin McInnes ; Bernd Dachwald
JF  - Journal of Spacecraft and Rockets. 44 (2007), H. 1
Y1  - 2007
SN  - 0022-4650
SP  - 273
EP  - 276
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - McDonald, Malcolm
A1  - McInnes, Colin R.
A1  - Mengali, Giovanni
T1  - Impact of Optical Degradation on Solar Sail Mission Performance
JF  - Journal of Spacecraft and Rockets. 44 (2007), H. 4
Y1  - 2007
SN  - 0022-4650
N1  - 2. ISSN: 1533-6794
SP  - 740
EP  - 749
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandrao A.
A1  - Macdonald, Malcolm
T1  - Parametric Model and Optimal Control of Solar Sails with Optical Degradation
JF  - Journal of guidance, control, and dynamics. 29 (2006), H. 5
Y1  - 2006
SN  - 0162-3192
N1  - 2. ISSN: 0731-5090
SP  - 1170
EP  - 1178
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro A.
A1  - Circi, Christian
T1  - Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ;  Bernd Dachwald
JF  - Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2
Y1  - 2007
SN  - 0162-3192
N1  - 2. ISBN: 0731-5090
SP  - 512
EP  - 520
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Mikucki, Jill
A1  - Tulaczyk, Slawek
A1  - Digel, Ilya
A1  - Espe, Clemens
A1  - Feldmann, Marco
A1  - Francke, Gero
A1  - Kowalski, Julia
A1  - Xu, Changsheng
T1  - IceMole : A maneuverable probe for clean in situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems
JF  - Annals of Glaciology
N2  - There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample.
KW  - Antarctic Glaciology
KW  - Extraterrestrial Glaciology
KW  - Glaciological instruments and methods
KW  - Subclacial exploration
KW  - Subglacial lakes
Y1  - 2014
U6  - http://dx.doi.org/10.3189/2014AoG65A004
SN  - 1727-5644
VL  - 55
IS  - 65
SP  - 14
EP  - 22
PB  - Cambridge University Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
T1  - 1st ACT Global Trajectory Optimisation Competition : Results found at DLR
JF  - Acta Astronautica. 61 (2007), H. 9
Y1  - 2007
SN  - 0094-5765
N1  - Global Trajectory Optimization ;  Results of the First Competition Organised by the Advanced Concept Team (ACT) of the European Space Agency (ESA)
SP  - 742
EP  - 752
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
A1  - Gill, E.
T1  - Optimization of low-thrust Earth-Moon transfers using evolutionary neurocontrol  / Ohndorf, A. ; Dachwald, B. ; Gill, E.
JF  - IEEE Congress on Evolutionary Computation, 2009. CEC '09.
Y1  - 2009
SN  - 978-1-4244-2958-5
SP  - 358
EP  - 364
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
A1  - Seboldt, W.
T1  - Optimierung der Lageregelung von Raumfahrzeugen mit Niedrigschubantrieb mittels evolutionärer neuronaler Regler / A. Ohndorf ; B. Dachwald ; W. Seboldt
JF  - Deutscher Luft- und Raumfahrtkongress 2005 : Friedrichshafen, 26. bis 29. September 2005, Motto: Luft- und Raumfahrt - Grenzen überwinden, Horizonte erweitern / Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. Bd. 3. - (Jahrbuch ... der Deutschen Gesellschaft für Luft- und Raumfahrt
Y1  - 2005
N1  - Deutscher Luft- und Raumfahrt-Kongress <2005, Friedrichshafen> ; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth ; Dokumentnr: DGLR-2005-224
SP  - 1971
EP  - 1978
PB  - DGLR
CY  - Bonn
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
A1  - Wie, Bong
T1  - Solar Sail Trajectory Optimization for the Solar Polar Imager (SPI) Mission
JF  - AIAA Guidance, Navigation, and Control Conference & Exhibit - AIAA Atmospheric Flight Mechanics Conference & Exhibit - AIAA Modeling and Simulation Technologies Conference & Exhibit - AIAA/AAS Astrodynamics Specialist Conference & Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )
Y1  - 2006
SN  - 1-56347-802-1
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; American Astronautical Society ; AIAA/AAS Astrodynamics Specialist Conference & Exhibit <2006,  Keystone, Colo.> ; AIAA paper number: AIAA-2006-6177
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Schmidt, Tanja D.
A1  - Seboldt, Wolfgang
A1  - Auweter-Kurtz, 
T1  - Flight Opportunities from Mars to Earth for Piloted Missions Using Continuous Thrust Propulsion / Schmidt, Tanja D. ; Dachwald, Bernd ; Seboldt, Wolfgang ; Auweter-Kurtz, Monika
Y1  - 2003
N1  - 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
20-23 July 2003, Huntsville, Alabama ; AIAA 2003-4573
SP  - 1
EP  - 9
PB  - -
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Multiple Near-Earth Asteroid Rendezvous and Sample Return Using First Generation Solar Sailcraft
JF  - Acta Astronautica. 57 (2005), H. 11
Y1  - 2005
SN  - 0094-5765
SP  - 864
EP  - 875
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Optimization of Interplanetary Rendezvous Trajectories for Solar Sailcraft Using a Neurocontroller
JF  - A collection of technical papers / AIAA Astrodynamics Specialist Conference : Monterey, California, 5 - 8 August 2002. - Vol. 2
Y1  - 2002
SN  - 1-56347-549-9
N1  - Astrodynamics Specialist Conference <2002, Monterey, Calif.> American Institute of Aeronautics and Astronautics <Reston, Va.>  ; AIAA  paper number: AIAA-2002-4989
SP  - 1263
EP  - 1270
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Solar Sails for Near- and Medium-Term Scientific Deep Space Missions / W. Sebolt ; B. Dachwald
JF  - In-space propulsion : edited book of proceedings of the 10-IWCP, the 10th International Workshop on Combustion and Propulsion held in Lerici, La Spezia, Italy, 21-25 September 2003 / [ed.: Luigi T. DeLuca]
Y1  - 2005
N1  - Paper 31 ; International workshop on combustion and propulsion <10, 2003, Lerici>
PB  - SP Lab, Politecnico di Milano
CY  - Milano
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Solar Sails — Propellantless Propulsion for Near- and Medium-Term Deep-Space Missions  / W. Seboldt ; B. Dachwald
JF  - Advanced Propulsion Systems and Technologies, Today to 2020 / Claudio Bruno (ed.) ... - (Progress in Astronautics and Aeronautics Series ; 223)
Y1  - 2008
SN  - 978-1-56347-929-8
N1  - ISBN 10: 1-56347-929-X  ; American Institute of Aeronautics and Astronautics <New York, NY>
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
A1  - Loeb, H. W
A1  - Schartner, K.-H.
T1  - Main Belt Asteroid Sample Return Mission Using Solar Electric Propulsion
JF  - Acta Astronautica. 63 (2008), H. 1-4
Y1  - 2008
SN  - 0094-5765
N1  - International Astronautical Federation Congress <58, 2007, Hyderabad> ; International Astronautical Congress <58, 2007, Hyderabad> ; IAC-07-A3.5.07
SP  - 91
EP  - 101
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
A1  - Lämmerzahl, W.
T1  - Solar Sail Propulsion: An Enabling Technology for Fundamental Physics Missions
JF  - Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansjörg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)
Y1  - 2008
SN  - 978-3-540-34376-9
SP  - 379
EP  - 398
PB  - Springer
CY  - Berlin [u.a.]
ER  -