ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • INSTRUMENTATION AND PHOTOGRAPHY  (9)
  • Organic Chemistry  (9)
  • 1990-1994  (18)
  • 1
    facet.materialart.
    Unknown
    A quadrant-CCD star tracker (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The characteristics of a quadrant-CCD designed for pointing and tracking are discussed with reference to its use in an adaptive optics program. The quadrant-CCD is used to correct stellar image motion proceeding from atmospheric turbulence by means of a system in which a sensor measures the image offset and sends data to a high-speed tip/tilt mirror. The design and control of the device are detailed, including four 100-micron-square pixels, the quadrant architecture, controller electronics, and data acquisition computer and interface. The transfer function is set forth in the x and y directions, and transfer curves are shown. A laboratory simulation of random image motion was conducted to evaluate the performance of the quadrant-CCD as an image motion sensor, and the experimental results are presented. The suitability of the quadrant-CCD for space-based pointing and tracking uses is demonstrated by this test and two earlier theoretical studies. Some future developments which improve performance capabilities are mentioned.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Charge-Coupled Devices and Solid State Optical Sensors; Feb 12, 1990 - Feb 14, 1990; Santa Clara, CA; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    GOMOS: Gobal Ozone Monitoring by Occultation of Stars (1994)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: In this paper we report on the progress and status of the Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument, and imaging spectrometer under development for flight on the European Space Agency's Polar Orbiting Earth Mission (POEM-1) mission in 1998. Employing occultation of stars as a light probe of the Earth's atmosphere from a sun-sychronous polar orbit, the instrument will monitor ozone and other atmospheric trace gases over the entire globe. Atmospheric transmission resolution of approximately 1.7 km. When data are combined regionally, it will be possible to detect ozone concentration trends as small as 0.05 percent/year, depending on the degree of combination.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA. Goddard Space Flight Center, Ozone in the Troposphere and Stratosphere, Part 2; p 950-953
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    A fiber-optic current sensor for aerospace applications (1990)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: A robust, accurate, broadband, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60-Hz terrestrial power systems and in 400-Hz aircraft systems. It is intrinsically electromagnetic interference (EMI) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. The technology used in the sensor is examined and the results of precision tests conducted at various temperatures within the wide operating range are given. The results of early EMI tests are also given.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IEEE Aerospace and Electronic Systems Magazine (ISSN 0885-8985); 5; 10-14
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Optical fiber sensor for temperature measurement from 600 to 1900 C in gas turbine engines (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: A temperature sensor system has been fabricated specifically for the harsh environment encountered in temperature measurement on gas turbine engines. Four components comprised the system: a thermally emissive source, a high temperature lightguide, a flexible optical cable and an electro-optic signal processor. The emissive source was located inside a sapphire rod so that the sapphire serves as both a lightguide and as a protective shroud. As the probe was heated, the thermal radiation from the emissive source increased with increasing temperature. The flexible optical cable was constructed with 200 micron core fiber and ruggedized for turbine engine applications. The electro-optic signal processor used the ratio of intensity in two wavelength intervals to determine a digital value of the temperature. The probe tip was operated above 1900 C in a low velocity propane flame and above 1500 C at Mach .37. Probe housings, optical cables, and signal processors were constructed and environmentally tested for the temperature and vibration experienced by turbine engine sensors. This technology was used to build an optical exhaust gas sensor for a General Electric Aircraft Engines F404 turbine. The four optical probes and optical cable were a functional replacement for four thermocouple probes. The system was ground tested for 50 hours with an excess of 1000 thermal cycles. This optical temperature sensor system measured gas temperature up to the operational limit of the turbine engine.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: In: Specialty fiber optic systems for mobile platforms; Proceedings of the Meeting, Boston, MA, Sept. 5, 1991 (A93-32915 12-74); p. 38-47.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Optical fiber voltage sensors for broad temperature ranges (1992)
    In:  Other Sources
    Details
    Publication Date: 2019-08-28
    Description: We describe the development of an optical fiber ac voltage sensor for aircraft and spacecraft applications. Among the most difficult specifications to meet for this application is a temperature stability of +/- 1 percent from -65 C to +125 C. This stability requires a careful selection of materials, components, and optical configuration with further compensation using an optical-fiber temperature sensor located near the sensing element. The sensor is a polarimetric design, based on the linear electro-optic effect in bulk Bi4Ge3O12. The temperature sensor is also polarimetric, based on the temperature dependence of the birefringence of bulk SiO2. The temperature sensor output is used to automatically adjust the calibration of the instrument.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: In: Fiber optic components and reliability; Proceedings of the Meeting, Boston, MA, Sept. 3-6, 1991 (A93-48532 20-74); p. 95-103.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    A fiber-optic current sensor for aerospace applications (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A robust, accurate, broadband, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low- and high-voltage 60-Hz terrestrial power systems and in 400-Hz aircraft systems. It is intrinsically EMI (electromagnetic interference) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a fiber-optic temperature sensor embedded in the sensing head. The authors report on the technology contained in the sensor and also relate the results of precision tests conducted at various temperatures within the wide operating range. The results of early EMI tests are shown.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Intersociety Energy Conversion Engineering Conference; Aug 12, 1990 - Aug 17, 1990; Reno, NV; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Fiber-optic sensors for aerospace electrical measurements: An update (1991)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Fiber-optic sensors are being developed for electrical current, voltage, and power measurements in aerospace applications. These sensors are presently designed to cover ac frequencies from 60 Hz to 20 kHz. The current sensor, based on the Faraday effect in optical fiber, is in advanced development after some initial testing. Concentration is on packaging methods and ways to maintain consistent sensitivity with changes in temperature. The voltage sensor, utilizing the Pockels effect in a crystal, has excelled in temperature tests. This paper reports on the development of these sensors, the results of evaluation, improvements now in progress, and the future direction of the work.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-104454 , E-6295 , NAS 1.15:104454 , Intersociety Energy Conversion Engineering Conference; Aug 04, 1991 - Aug 09, 1991; Boston, MA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    A fiber-optic current sensor for aerospace applications (1990)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A robust, accurate, broad-band, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60 Hz terrestrial power systems and in 400 Hz aircraft systems. It is intrinsically electromagnetic interference (EMI) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. The technology contained in the sensor is examined and the results of precision tests conducted at various temperatures within the wide operating range are given. The results of early EMI tests are also given.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-TM-103152 , E-5513 , NAS 1.15:103152 , Intersociety Energy Conversion Engineering Conference; Aug 12, 1990 - Aug 17, 1990; Reno, NV; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Fiber-optic sensors for aerospace electrical measurements - An update (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-08-27
    Description: The authors report the progress made on the development of aerospace current and voltage sensors which use fiber-optic and optical sensing heads. These sensors are presently designed to cover ac frequencies from 60 Hz to 20 kHz. The current sensor, based on the Faraday effect in optical fiber, is in advanced development after some initial testing. The emphasis is on packaging methods and ways to maintain consistent sensitivity with changes in temperature. The voltage sensor, utilizing the Pockels effect in a crystal, has excelled in temperature tests. The authors report on the development of these sensors. The authors also relate the technology used in the sensors, the results of evaluation, improvements being made, and the future direction of the work.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: IECEC ''91: Intersociety Energy Conversion Engineering Conference; Aug 04, 1991 - Aug 09, 1991; Boston, MA; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    Electronic Resource
    Electronic Resource
    Novel photocycloadditions of electron-deficient nitrones to 2-methyl-2-butene (1991)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1991 (1991), S. 513-517 
    Details
    ISSN: 0170-2041
    Keywords: Nitrones, electron-deficient ; Oxaziridines ; Dipolarophiles ; [3+2]Photocycloadditions ; Oxazolidines ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In Order to decrease the ground state reactivity and increase their potential for [3+2] cycloadditions, cyano- and methoxy-carbonyl-substituted nitrones 1a and 1b, respectively, were prepared and irradiated in the presence of electron-rich alkenes such as 2 to afford the corresponding oxazolidines in which th oxygen atom becomes attached to the least substituted terminus of the olefin and nitrogen attaches to the more highly substituted counterpart. While the oxazolidines 12a and 12b obtained from 1b, via the intermediacy of oxaziridine(s) 15 and subsequent N—O bond scission, are isolated and characterized, the oxazolidin(s) 18 formed bny cyclization of 1a are more labile and may undergo ionization to the stabilized oxazolinium ion 19 followed by nucleophilic attack by cyanide ion with accompanying ring opening to afford 6. A sequential diradical mechanism is proposed to rationalize the formation of the observed photoproducts 5 and 6.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199119910194
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...