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
  • Aeronautics (General)  (4)
  • Conservation of Natural Resources  (4)
  • Astrophysics
  • 2000-2004  (10)
  • 1
    facet.materialart.
    Unknown
    A global paleoclimate observing system (2001)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2001-07-11
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Alverson, K -- Bradley, R -- Briffa, K -- Cole, J -- Hughes, M -- Larocque, I -- Pedersen, T -- Thompson, L -- Tudhope, S -- New York, N.Y. -- Science. 2001 Jul 6;293(5527):47-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11444288" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Carbon Dioxide/metabolism ; *Climate ; Cnidaria/physiology ; Conservation of Natural Resources ; Greenhouse Effect ; Humans ; Ice ; Oceans and Seas ; Rain ; Seawater/analysis/chemistry ; Specimen Handling/*methods ; Temperature ; Time Factors ; Trees/growth & development/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Historical overfishing and the recent collapse of coastal ecosystems (2001)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2001-07-28
    Description: Ecological extinction caused by overfishing precedes all other pervasive human disturbance to coastal ecosystems, including pollution, degradation of water quality, and anthropogenic climate change. Historical abundances of large consumer species were fantastically large in comparison with recent observations. Paleoecological, archaeological, and historical data show that time lags of decades to centuries occurred between the onset of overfishing and consequent changes in ecological communities, because unfished species of similar trophic level assumed the ecological roles of overfished species until they too were overfished or died of epidemic diseases related to overcrowding. Retrospective data not only help to clarify underlying causes and rates of ecological change, but they also demonstrate achievable goals for restoration and management of coastal ecosystems that could not even be contemplated based on the limited perspective of recent observations alone.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jackson, J B -- Kirby, M X -- Berger, W H -- Bjorndal, K A -- Botsford, L W -- Bourque, B J -- Bradbury, R H -- Cooke, R -- Erlandson, J -- Estes, J A -- Hughes, T P -- Kidwell, S -- Lange, C B -- Lenihan, H S -- Pandolfi, J M -- Peterson, C H -- Steneck, R S -- Tegner, M J -- Warner, R R -- New York, N.Y. -- Science. 2001 Jul 27;293(5530):629-37.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0244, USA. jbcj@ucsd.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11474098" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Archaeology ; Bacteria ; Cnidaria ; Conservation of Natural Resources ; *Ecosystem ; Eutrophication ; *Fishes ; Geologic Sediments ; Humans ; *Marine Biology ; Seaweed ; Shellfish ; Time Factors
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Regional-scale assembly rules and biodiversity of coral reefs (2001)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2001-05-26
    Description: Tropical reef fishes and corals exhibit highly predictable patterns of taxonomic composition across the Indian and Pacific Oceans. Despite steep longitudinal and latitudinal gradients in total species richness, the composition of these key taxa is constrained within a remarkably narrow range of values. Regional-scale variation in reef biodiversity is best explained by large-scale patterns in the availability of shallow-water habitat. Once habitat area is accounted for, there is surprisingly little residual effect of latitude or longitude. Low-diversity regions are most vulnerable to human impacts such as global warming, underscoring the urgent need for integrated management at multinational scales.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bellwood, D R -- Hughes, T P -- New York, N.Y. -- Science. 2001 May 25;292(5521):1532-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre for Coral Reef Biodiversity, Department of Marine Biology, James Cook University, Townsville, Qld 4811, Australia. david.bellwood@jcu.edu.au〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11375488" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Cnidaria/classification/physiology ; Conservation of Natural Resources ; *Ecosystem ; *Fishes/classification/physiology ; Geography ; Greenhouse Effect ; Indian Ocean ; Pacific Ocean ; Temperature
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Global trajectories of the long-term decline of coral reef ecosystems (2003)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2003-08-16
    Description: Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pandolfi, John M -- Bradbury, Roger H -- Sala, Enric -- Hughes, Terence P -- Bjorndal, Karen A -- Cooke, Richard G -- McArdle, Deborah -- McClenachan, Loren -- Newman, Marah J H -- Paredes, Gustavo -- Warner, Robert R -- Jackson, Jeremy B C -- New York, N.Y. -- Science. 2003 Aug 15;301(5635):955-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Paleobiology, MRC-121, National Museum of Natural History, Post Office Box 37012, Smithsonian Institution, Washington, DC 20013-7012, USA. pandolfi.john@nmnh.si.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12920296" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Anthozoa/*growth & development ; Conservation of Natural Resources ; Culture ; *Ecosystem ; Humans ; Population Dynamics ; Principal Component Analysis ; Time Factors
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Steady and Unsteady Flow Field Measurements Within a NASA 22-Inch Fan Model (2003)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Results are presented of an experiment conducted to investigate possible sources of fan noise in the flow developed by a 22-in. (55.9 cm) diameter turbofan model. Flow diagnostic data were acquired to identify possible sources of both tone and broadband noise. Laser Doppler velocimetry was used to characterize the tip flows that develop within the rotor blade passages, the wake flow downstream of the rotor, and the shock waves that develop on the blades when operated at transonic relative tip speeds. Single-point hot-wire measurements were made in the rotor wake to determine the frequency content and the length scales of the flow unsteadiness. The results document the changes in the rotor wake flow with both rotor speed and axial distance downstream of the rotor. The data also show the tip flow development within the blade passage, its migration downstream, and (at high rotor speeds) its merging with the blade wake of the following blade. Data also depict the variation of the tip flow with tip clearance. LDV data obtained within the blade passages at high rotor speeds illustrate the passage-to-passage variation of the mean shock position. Spectra computed from the single-point hot-wire measurements illustrate how the energy in the flow oscillations is split between periodic and random components, and how this split varies with both radial and axial position in the rotor wake.
    Keywords: Aeronautics (General)
    Type: NASA/TM-2003-212329 , NAS 1.15:212329 , E-13924 , AIAA Paper 2002-1033 , 40th Aerospace Sciences Meeting and Exhibit; Jan 14, 2003 - Jan 17, 2003; Reno, NV; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Fan Noise Source Diagnostic Test: LDV Measured Flow Field Results (2003)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Results are presented of an experiment conducted to investigate potential sources of noise in the flow developed by two 22-in. diameter turbofan models. The R4 and M5 rotors that were tested were designed to operate at nominal take-off speeds of 12,657 and 14,064 RPMC, respectively. Both fans were tested with a common set of swept stators installed downstream of the rotors. Detailed measurements of the flows generated by the two were made using a laser Doppler velocimeter system. The wake flows generated by the two rotors are illustrated through a series of contour plots. These show that the two wake flows are quite different, especially in the tip region. These data are used to explain some of the differences in the rotor/stator interaction noise generated by the two fan stages. In addition to these wake data, measurements were also made in the R4 rotor blade passages. These results illustrate the tip flow development within the blade passages, its migration downstream, and (at high rotor speeds) its merging with the blade wake of the adjacent (following) blade. Data also depict the variation of this tip flow with tip clearance. Data obtained within the rotor blade passages at high rotational speeds illustrate the variation of the mean shock position across the different blade passages.
    Keywords: Aeronautics (General)
    Type: NASA/TM-2003-212330 , E-13925 , NAS 1.15:212330 , AIAA Paper 2002-2431 , Eight Aeroacoustics Conference; Jun 17, 2002 - Jun 19, 2002; Breckenridge, CO; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Sunyaev-Zeldovich Effect-Derived Distances to the High-Redshift Clusters (2000)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: We determine the distances to the z approximately equals 0.55 galaxy clusters MS 0451.6 - 0305 and Cl 0016 + 16 from a maximum-likelihood joint fit to interferometric Sunyaev-Zeldovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM) using a spherical isothermal beta model. We quantify the statistical and systematic uncertainties inherent to these direct distance measurements, and we determine constraints on the Hubble parameter for three different cosmologies. For an Omega(sub M) = 0.3, Omega(sub lambda) = 0.7 cosmology, these distances imply a Hubble constant of 63(sup +12) (sub -9) (sup + 21) (sub -21) km/s Mp/c, where the uncertainties correspond to statistical followed by systematic at 68% confidence. The best-fit H(sub 0) is 57 km/s Mp/c for an open (Omega(sub M) = 0.3) universe and 52 km/s Mp/c for a flat (Omega(sub M) = 1) universe.
    Keywords: Astrophysics
    Type: Astrophysical Journal; 533; 38-49
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Acoustic Benefits of Stator Sweep and Lean for a High Tip Speed Fan (2002)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A model high-speed fan stage was acoustically tested in the NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel at takeoff/approach flight conditions. The fan was designed for a corrected rotor tip speed of 442 m/s (1450 ft/s), and had a powered core, or booster stage, giving the model a nominal bypass ratio of 5. The model also had a simulated engine pylon and nozzle bifurcation contained within the bypass duct. The fan was tested with three stator sets to evaluate acoustic benefits associated with a swept and leaned stator and with a swept integral vane/frame stator which incorporated some of the swept and leaned features as well as eliminated some of the downstream support structure. The baseline fan with the wide chord rotor and baseline stator approximated a current GEAE CF6 engine. A flyover effective perceived noise level (EPNL) code was used to generate relative EPNL values for the various configurations. Flyover effective perceived noise levels (EPNL) were computed from the model data to help project noise benefits. A tone removal study was also performed. The swept and leaned stator showed a 3 EPNdB reduction at lower fan speeds relative to the baseline stator; while the swept integral vane/frame stator showed lowest noise levels at intermediate fan speeds. Removal of the bypass blade passage frequency rotor tone (BPF) showed a 4 EPNdB reduction for the baseline and swept and leaned stators, and a 6 EPNdB reduction for the swept integral vane/ frame stator. Therefore, selective tone removal techniques such as active noise control and/or tuned liner could be particularly effective in reducing noise levels for certain fan speeds.
    Keywords: Aeronautics (General)
    Type: NASA/TM-2002-211345 , E-13143 , NAS 1.15:211345 , AIAA Paper 2002-1034 , 40th Aerospace Sciences Meeting and Exhibit; Jan 14, 2002 - Jan 17, 2002; 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
    The Distance and Mass of the Galaxy Cluster Abell 1995 Derived from Sunyaev-Zeldovich Effect and X-Ray Measurements (2000)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: We present multiwavelength observations of the Abell 1995 galaxy cluster. From an analysis of X-ray spectroscopy and imaging data, we derive the electron temperature, cluster core radius, and central electron number density. Using optical spectroscopy of 15 cluster members, we derive an accurate cluster redshift and velocity dispersion. Finally, the interferometric imaging of the Sunyaev-Zeldovich effect toward Abell 1995 at 28.5 GHz provides a measure of the integrated pressure through the cluster. The X-ray and Sunyaev-Zeldovich effect observations are combined to determine the angular diameter distance to the cluster of D(sub A) = 1294(sup +294 +438, sub -283 -458) Mpc (Statistical followed by systematic uncertainty), implying a Hubble constant of H(sub 0) = 52.2(sup +11.4 +18.5, sub -11.9 -17.7) km/s.Mpc for Omega(sub M) = 0.3 and Omega(sub lambda) = 0.7. We find a best-fit H(sub 0) of 46 km/s.Mpc for the Omega(sub M) = 1 and Omega(sub lambda) = 0 cosmology, and 48 km/s.Mpc for Omega(sub M) = 0.3 and Omega(sub lambda) = 0.0. The X-ray data are also used to derive a total cluster mass of M(sup HSE, sub tot)(r(sub 500)) = 5.18(sup +0.62, sub -0.48) x 10(exp 14)/h solar mass; the optical velocity dispersion yields an independent and consistent estimate of M(sup virial, sub tot)(r(sub 500)) = 6.35(sup +1.51, sub -1.19) X 10(exp 14) /h solar mass. Both of the total mass estimates are evaluated at a fiducial radius, r(sub 500) = 830 /h kpc, where the overdensity is 500 times the critical density. The total cluster mass is then combined with gas mass measurements to determine a cluster gas mass fraction of F(sub g) = 0.056(sup +0.010, sub -0.013) /h(sup 3/2) in combination with recent baryon density constraints, the measured gas mass fraction yields an upper limit on the mass density parameter of Omega(sub M) h(sup 1/2) 〈= 0.34(sup +/0.06, sub 0.05.
    Keywords: Astrophysics
    Type: Astrophysical Journal; 541; 37-48
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Noise Benefits of Increased Fan Bypass Nozzle Area (2004)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: An advanced model turbofan (typical of current engine technology) was tested in the NASA Glenn 9 by 15 Foot Low Speed Wind Tunnel (9-by 15-Foot LSWT) to explore far field acoustic effects of increased bypass nozzle area. This fan stage test was part of the NASA Glenn Fan Broadband Source Diagnostic Test, second entry (SDT2) which acquired aeroacoustic results over a range of test conditions. The baseline nozzle was sized to produce maximum stage performance for the engine at a high altitude, cruise point condition. However, the wind tunnel testing is conducted near sea level conditions. Therefore, in order to simulate and obtain performance at other aircraft operating conditions, two additional nozzles were designed and tested-one with a +5 percent increase in weight flow (+5.4 percent increase in nozzle area compared with the baseline nozzle), sized to simulate the performance at the stage design point conditions, and the other with a +7.5 percent increase in weight flow (+10.9 percent increase in nozzle area), sized for maximum weight flow with a fixed nozzle at sea level conditions. Measured acoustic benefits with increased nozzle area were very encouraging, showing overall sound power level (OAPWL) reductions of 2 or more dB while the stage thrust actually increased by several percentage points except fro the most open nozzle at takeoff rotor speed where stage performance decreased. These noise reduction benefits were seen to primarily affect broadband noise, and were evident throughout the range of measured sideline angles.
    Keywords: Aeronautics (General)
    Type: NASA/TM-2004-213396 , AIAA Paper 2005-1201 , E-14899 , 43rd Aerospace Sciences Meeting and Exhibit; Jan 10, 2005 - Jan 13, 2005; Reno, NV; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...