Refine
Year of publication
- 2006 (160) (remove)
Institute
- Fachbereich Medizintechnik und Technomathematik (64)
- Fachbereich Luft- und Raumfahrttechnik (21)
- IfB - Institut für Bioengineering (20)
- INB - Institut für Nano- und Biotechnologien (18)
- Fachbereich Elektrotechnik und Informationstechnik (17)
- Fachbereich Maschinenbau und Mechatronik (15)
- Fachbereich Chemie und Biotechnologie (12)
- Fachbereich Energietechnik (12)
- Fachbereich Wirtschaftswissenschaften (7)
- Fachbereich Bauingenieurwesen (3)
Language
- English (160) (remove)
Document Type
- Article (86)
- Conference Proceeding (60)
- Book (9)
- Lecture (2)
- Part of a Book (1)
- Master's Thesis (1)
- Report (1)
Keywords
- Biosensor (23)
- Technische Mechanik (2)
- biosensor (2)
- 3-nitrofluoranthene (1)
- Asteroid Deflection (1)
- BTEX compounds (1)
- Bauingenieurwesen (1)
- Biosensorik (1)
- Bruchmechanik (1)
- CAD (1)
A multi-sensor system is a chemical sensor system which quantitatively and qualitatively records gases with a combination of cross-sensitive gas sensor arrays and pattern recognition software. This paper addresses the issue of data analysis for identification of gases in a gas sensor array. We introduce a software tool for gas sensor array configuration and simulation. It concerns thereby about a modular software package for the acquisition of data of different sensors. A signal evaluation algorithm referred to as matrix method was used specifically for the software tool. This matrix method computes the gas concentrations from the signals of a sensor array. The software tool was used for the simulation of an array of five sensors to determine gas concentration of CH4, NH3, H2, CO and C2H5OH. The results of the present simulated sensor array indicate that the software tool is capable of the following: (a) identify a gas independently of its concentration; (b) estimate the concentration of the gas, even if the system was not previously exposed to this concentration; (c) tell when a gas concentration exceeds a certain value. A gas sensor data base was build for the configuration of the software. With the data base one can create, generate and manage scenarios and source files for the simulation. With the gas sensor data base and the simulation software an on-line Web-based version was developed, with which the user can configure and simulate sensor arrays on-line.
Near-Earth asteroid 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several so-called gravitational keyholes during its 2029-encounter. Several pre-2029-deflection scenarios to prevent Apophis from doing this have been investigated so far. Because the keyholes are less than 1 km in size, a pre-2029 kinetic impact is clearly the best option because it requires only a small change in Apophis' orbit to nudge it out of a keyhole. A single solar sail Kinetic Energy Impactor (KEI) spacecraft that impacts Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages at about 0.75 AU would be a feasible option to do this. The spacecraft consists of a 160 m x 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. In this paper, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, solar sail Kinetic Energy Impactor (KEI) spacecraft are still a feasible option to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value. In this paper, we elaborate potential pre- and post-2029 KEI impact scenarios for a launch in 2020, and investigate tradeoffs between different mission parameters.