Refine
Year of publication
- 2011 (328) (remove)
Institute
- Fachbereich Medizintechnik und Technomathematik (82)
- Fachbereich Elektrotechnik und Informationstechnik (40)
- INB - Institut für Nano- und Biotechnologien (37)
- Fachbereich Wirtschaftswissenschaften (34)
- IfB - Institut für Bioengineering (34)
- Fachbereich Energietechnik (29)
- Fachbereich Chemie und Biotechnologie (28)
- Fachbereich Bauingenieurwesen (24)
- Fachbereich Maschinenbau und Mechatronik (24)
- Fachbereich Luft- und Raumfahrttechnik (23)
Document Type
- Article (182)
- Conference Proceeding (76)
- Book (24)
- Part of a Book (21)
- Report (7)
- Patent (5)
- Conference: Meeting Abstract (3)
- Other (3)
- Doctoral Thesis (2)
- Part of a Periodical (2)
Keywords
- Aachen / Fachhochschule Aachen (3)
- Aachen University of Applied Sciences (3)
- Aktionskunst (3)
- FH Aachen (2)
- Illustration (2)
- Interaktive Kunst (2)
- Kommunikationsguerrilla (2)
- Pflanzenphysiologie (2)
- Pflanzenscanner (2)
- Stadtgestaltung (2)
Bio-feedstocks
(2011)
At (ultra)high magnetic fields the artifact sensitivity of ECG recordings increases. This bears the risk of R-wave mis-registration which has been consistently reported for ECG triggered CMR at 7.0T. Realizing the constraints of conventional ECG, acoustic cardiac triggering (ACT) has been proposed. The clinical ACT has not been carefully examined yet. For this reason, this work scrutinizes the suitability, accuracy and reproducibility of ACT for CMR at 7.0T. For this purpose, the trigger reliability and trigger detection variance are examined together with an qualitative and quantitative assessment of image quality of the heart at 7.0T.
Anmerkung zu EuGH, Urt. v. 1.3.2011, Rs. C-236/09 Association belge des Consomma-teurs Test-Achats
(2011)
Originalausgabe: Orthopädische Praxis Jg. 47. 2011 H. 11; S. 536-543. Mit freundlicher Genehmigung des Verlags Zusammenfassung: Auf der Basis von Patientenabfragen mittels Fragebogen zum Schmerzempfinden und zur Einschränkung bei Aktivitäten des alltäglichen Lebens wird die Langzeitwirkung der MBST® KernspinResonanz-Therapie bei Gonarthrose untersucht. An der Studie nahmen 39 Patienten teil, bei denen die Therapie bis zu vier Jahre zurückliegt. Neben einer Gesamtbetrachtung wird der Erfolg auch in Abhängigkeit von Alter, Geschlecht und sportlicher Aktivität analysiert. Insgesamt weist die Studie auf eine anhaltende Verbesserung des Gesundheitszustands mit zum Teil deutlicher Schmerzlinderung auch noch nach vier Jahren hin, jedoch mit einer leichten Schmerzzunahme gegen Ende des Untersuchungszeitraums von vier Jahren. Eine tendenziell positivere Wirkung bei Frauen, älteren Menschen oder auch sportlich nicht-aktiven Patienten lässt auf eine mögliche Beeinflussung des Erfolgs der Therapie durch (Über-)Belastung im Alltag schließen. Ein zusätzlich positiver Effekt der Therapie auf die Knochendichte ist ebenfalls denkbar, dies bleibt jedoch offen.
An Interstellar – Heliopause mission using a combination of solar/radioisotope electric propulsion
(2011)
There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft travelling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by ESA.Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope electric propulsion. As a further alternative, we here investigate a combination of solar-electric propulsion and radioisotope-electric propulsion. The solar-electric propulsion stage consists of six 22 cm diameter “RIT-22”ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW BOM is provided by a light-weight solar array. The REP-stage consists of four space-proven 10 cm diameter “RIT-10” ion thrusters that will be operating one after the other for 9 yrs in total. Four advanced radioisotope generators provide 648 W at BOM. The scientific instrument package is oriented at earlier studies. For its mass and electric power requirement 35 kg and 35 W are assessed, respectively. Optimized trajectory calculations, treated in a separate contribution, are based on our “InTrance” method.The program yields a burn out of the REP stage in a distance of 79.6 AU for a usage of 154 kg of Xe propellant. With a C3 = 45,1 (km/s)2 a heliocentric probe velocity of 10 AU/yr is reached at this distance, provided a close Jupiter gravity assist adds a velocity increment of 2.7 AU/yr. A transfer time of 23.8 yrs results for this scenario requiring about 450 kg Xe for the SEP stage, jettisoned at 3 AU. We interpret the SEP/REP propulsion as a competing alternative to solar sail and ballistic/REP propulsion. Omiting a Jupiter fly-by even allows more launch flexibility, leaving the mission duration in the range of the ESA specification.
The importance of the availability of stored blood or blood cells, respectively, for urgent transfusion cannot be overestimated. Nowadays, blood storage becomes even more important since blood products are used for epidemiological studies, bio-technical research or banked for transfusion purposes. Thus blood samples must not only be processed, stored, and shipped to preserve their efficacy and safety, but also all parameters of storage must be recorded and reported for Quality Assurance. Therefore, blood banks and clinical research facilities are seeking more accurate, automated means for blood storage and blood processing.
Inhaltsverzeichnis: 4 Grußwort des Dekans [Prof. Dr.-Ing. Jürgen Kettern] 4 Grußwort des Sektionsleiters "Bau" des alfha.net [Dipl.-Ing. Walter Kleiker] 5 Referenten 10 Referate 10 Die Statik bleibt dynamisch ... : Beispiele der Schwingungsanfälligkeit von Brücken, Türmen und erdbebengefährdeten Gebäuden / Dipl.-Ing. Sebastian Gokus 12 Bau einer Biogasanlage / Dipl.-Ing. Michaela Schneider 16 Die neue Landmarke an der A4 / Dipl.-Ing. Franz-Josef Türck-Hövener 18 Technical Due Diligence Real Estate : Technische Immobilienbewertung zur Vorbereitung einer Immobilientransaktion - Eine Teilanalyse von Chancen und Risiken im Due Diligence Prozess / Dipl.-Ing. Architektin Ebru Baykal M.Eng. 20 Die Deutsche Botschaft Kabul wird saniert / Dipl.-Ing. Stefanie Milde 24 Abfluss- und Strukturverbesserung am Niederrhein : Ein hydraulischer Ansatz zur Vereinbarkeit von Hochwasserschutz und Strukturverbesserung / Dr.-Ing. Gesa Kutschera 26 Um- und Ausbau des Autobahnkreuzes Aachen / Dipl.-Ing. Dirk Gobbelé 30 Textilbewehrter Beton in Großprojekten am Beispiel einer Fußgängerbrücke / Dipl.-Ing. Andre Nacken 32 Kalkulation in der Bauindustrie / Dipl.-Ing. Alexander Spix 34 Phoenix-See Dortmund : Standort für die Zukunft / Dipl,-Ing. Stephan Bendel ; Dipl.-Ing. Sebastian Nyßen 38 alfha.net - Ein Verein stellt sich vor 39 Impressum
Air-sand heat exchanger
(2011)
Air-pulse corneal applanation signal curve parameters for the characterisation of keratoconus
(2011)
Absatzkanäle kaum verknüpft
(2011)
Objective:
To develop a transmit/receive radiofrequency (RF) array for magnetic resonance imaging (MRI) of the carotid arteries at 7 T. The prototype is characterized in numerical simulations and bench measurements, and the feasibility of plaque imaging at 7 T is demonstrated in first in vivo images.
Materials and Methods:
The RF phased array coil consists of 8 surface loop coils. To allow imaging of both sides of the neck, the RF array is divided into 2 coil clusters, each with 4 overlapping loop elements. For safety validation, numerical computations of the RF field distribution and the corresponding specific absorption rate were performed on the basis of a heterogeneous human body model. To validate the coil model, maps of the transmit B1+ field were compared between simulation and measurement. In vivo images of a healthy volunteer and a patient (ulcerating plaque and a 50% stenosis of the right internal carotid artery) were acquired using a 3-dimensional FLASH sequence with a high isotropic spatial resolution of 0.54 mm as well as using pulse-triggered proton density (PD)/T2-weighted turbo spin echo sequences.
Results:
Measurements of the S-parameters yielded a reflection and isolation of the coil elements of better than −18 and −13 dB, respectively. Measurements of the g-factor indicated good image quality for parallel imaging acceleration factors up to 2.4. A similar distribution and a very good match of the absolute values were found between the measured and simulated B1+ transmit RF field for the validation of the coil model. In vivo images revealed good signal excitation of both sides of the neck and a high vessel-to-background image contrast for the noncontrast-enhanced 3-dimensional FLASH sequence. Imaging at 7 T could depict the extent of stenosis, and revealed the disruption and ulcer of the plaque.
Conclusions:
This study demonstrates that 2 four-channel transmit/receive RF arrays for each side of the neck is a suitable concept for in vivo MRI of the carotid arteries at 7 Tesla. Further studies are needed to explore and exploit the full potential of 7 T high-field MRI for carotid atherosclerotic plaque imaging.
The msprop program presented in this work is capable of solving the Maxwell–Schrödinger equations for one or several laser fields propagating through a medium of quantum optical few-level systems in one spatial dimension and in time. In particular, it allows to numerically treat systems in which a laser field interacts with the medium with both its electric and magnetic component at the same time. The internal dynamics of the few-level system is modeled by a quantum optical master equation which includes coherent processes due to optical transitions driven by the laser fields as well as incoherent processes due to decay and dephasing. The propagation dynamics of the laser fields is treated in slowly varying envelope approximation resulting in a first order wave equation for each laser field envelope function. The program employs an Adams predictor formula second order in time to integrate the quantum optical master equation and a Lax–Wendroff scheme second order in space and time to evolve the wave equations for the fields. The source function in the Lax–Wendroff scheme is specifically adapted to allow taking into account the simultaneous coupling of a laser field to the polarization and the magnetization of the medium. To reduce execution time, a customized data structure is implemented and explained. In three examples the features of the program are demonstrated and the treatment of a system with a phase-dependent cross coupling of the electric and magnetic field component of a laser field is shown.