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  • 1
    Electronic Resource
    Electronic Resource
    Carbon budget for the spring bloom in Auke Bay, Alaska (1993)
    Springer
    Marine biology 115 (1993), S. 509-521 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper describes a carbon budget for the spring phytoplankton bloom in Auke Bay, a subarctic bay in southeastern Alaska. The budget was constructed using semiweekly data on carbon production, particulate carbon in the water column, and cumulative sedimentation of carbon, chlorophyll a, and pheopigments. From these measured parameters, seasonal carbon consumption, utilization, and import/export terms were derived. The chlorophyll and pheopigment data were used to partition carbon sinking out of the photic zone between phytoplankton cells and fecal material. The difference between total carbon production and carbon available for consumption was attributed primarily to carbon import/export related to advection of water masses into and out of the bay. Separate budgets were developed for each of five sampling years (1985–1989). An average of 130±16 g C/m2 were produced by phytoplankton during each spring. Our model suggests that an average of 70% of this carbon was available for consumption by grazers within the bay; the remaining 30% is assumed to have been exported from the bay by advective transport. Of the available (non-exported) carbon, an average of 55% was consumed by grazers, 34% sank out of the photic zone in the form of uneaten algae, and about 11% remained at the end of the sampling period in the form of phytoplankton standing stocks. Overall, about 27% of the carbon produced each spring in Auke Bay (≈35 gC/m2) was used for growth and respiration by first-order consumers within the bay.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349850
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  • 2
    Electronic Resource
    Electronic Resource
    The effect of pyruvate on nitrogenase activity in the blue-green alga Anabaena cyclindrica (1975)
    Springer
    Archives of microbiology 105 (1975), S. 61-66 
    Details
    ISSN: 1432-072X
    Keywords: Nitrogenase ; Anabaena ; Pyruvate: Ferredoxin Oxidoreductase ; Blue-Green Alga
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Exogenous pyruvate added to cultures of the bluegreen alga, Anabaena cylindrica stimulated nitrogenase activity (measured by acetylene reduction) only in the dark under low pO2 (0.05 atmospheres). Under aerobic conditions or in the light, stimulation was absent and replaced by an inhibition of activity above 5 mM added pyruvate. The curve of nitrogenase activity versus oxygen concentration had a similar maximal value of ethylene production with or without added pyruvate, but in the presence of pyruvate this maximum occurred at 0.05 atmospheres O2, whilst in the absence of pyruvate the maximum occurred at 0.10 atmospheres O2. Malate, citrate, α-ketoglutarate, glucose and fructose were tested also, but none gave a similar effect to pyruvate. Addition of 14C-pyruvate and autoradiography indicated that exogenous pyruvate is metabolized through the interrupted Krebs cycle. These results are explained in terms of the activity of pyruvate: ferredoxin oxidoreductase and the ATP-induced oxygen sensitivity of nitrogenase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447114
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  • 3
    Electronic Resource
    Electronic Resource
    Embedded optical fiber sensors for materials evaluation (1989)
    Springer
    Journal of nondestructive evaluation 8 (1989), S. 135-145 
    Details
    ISSN: 1573-4862
    Keywords: Optical fibers ; fiber optic sensors ; embedded sensors ; composite materials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics
    Notes: Abstract Optical fiber waveguides embedded within materials have been applied to the measurement of chemical changes, strain, and temperature inside materials. This paper reviews some of the research that has been performed in this area over the past 10 years and cites the theoretical and demonstrated performance of such sensors for material evaluation during its manufacturing, in service lifetime and degradation periods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00565637
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  • 4
    Electronic Resource
    Electronic Resource
    Waves in Twisted Magnetic Flux Tubes (1999)
    Springer
    Solar physics 185 (1999), S. 41-59 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The modes of oscillation of a twisted magnetic flux tube in an incompressible medium are investigated analytically. An exact dispersion relation for the case of uniform twist is obtained. In contrast to the case of an untwisted incompressible tube, body, surface, and hybrid (surface-body) modes arise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005141432432
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  • 5
    Electronic Resource
    Electronic Resource
    Empirical Studies of Evolving Systems (1999)
    Springer
    Empirical software engineering 4 (1999), S. 370-380 
    Details
    ISSN: 1573-7616
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper describes the results of the working group investigating the issues of empirical studies for evolving systems. The groups found that there were many issues that were central to successful evolution and this concluded that this is a very important area within software engineering. Finally nine main areas were selected for consideration. For each of these areas the central issues were identified as well as success factors. In some cases success stories were also described and the critical factors accounting for the success analysed. In some cases it was later found that a number of areas were so tightly coupled that it was important to discuss them together.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009869705323
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  • 6
    Electronic Resource
    Electronic Resource
    Orthogonal stagnation flow, a framework for steady extensional flow experiments (1979)
    Springer
    Rheologica acta 18 (1979), S. 323-334 
    Details
    ISSN: 1435-1528
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zusammenfassung Es werden neue Leitlinien zur Beurteilung von stationären Dehnströmungs-Experimenten vorgeschlagen: Die stationäre orthogonale Staupunktströmung wird als ein Ideal herausgestellt, das man in Experimenten zu erreichen versuchen sollte. Die Kinematik und die Randbedingung für das Spannungsfeld werden für allgemeine Staupunktströmungen hergeleitet und auf zwei Sonderfälle angewendet: die axialsymmetrische und die ebene Staupunktströmung. Der Vergleich dieser idealen Strömung mit wirklichen Experimenten verdeutlicht deren jeweilige Vor- und Nachteile und weist so auf neue Experimente hin. Mehrere neue Experimente werden vorgeschlagen. Die axialsymmetrisch nach außen gerichtete und die ebene Staupunktströmung in Düsen mit geschmierten Wandungen erscheinen besonders erfolgversprechend. Einige vorläufige experimentelle Ergebnisse für die einachsige Dehnströmung einer Polyacrylamidlösung in einer mit Wasser geschmierten Düse werden vorgestellt.
    Notes: Summary A new framework for viewing steady extensional flow is presented: Steady orthogonal stagnation flow is an ideal which one should strive to reach in an actual experiment. The kinematics and the stress boundary conditions are developed for stagnation flow in general and in two special cases: the impingement of two circular streams and of two planar sheets. Contemplating this ideal clarifies the advantages and disadvantages of current experiments, thereby pointing the way towards new experiments; a number are suggested. Axisymmetric (with $$\dot \varepsilon _x $$ 〉 0) and planar stagnation flow within a lubricated die look particularly promising. Some preliminary experimental results are given for uniaxial extension of a polyacrylamide solution in a water lubricated die.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01515825
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  • 7
    Electronic Resource
    Electronic Resource
    The first two years of the BATSE/COMPTEL/NMSU GRB Rapid Response Network (1995)
    Springer
    Astrophysics and space science 231 (1995), S. 251-254 
    Details
    ISSN: 1572-946X
    Keywords: Gamma-ray bursts ; Optical and radio observations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The BATSE/COMPTEL/NMSU Rapid Response Network (RRN) was formed to provide rapid follow-up ofγ-ray bursts imaged by the COMPTEL instrument on the Compton Gamma-Ray Observatory. The RRN consists of ≈ 22 professional observatories located around the world spanning both northern and southern hemispheres. Also included in the RRN is the Airforce GEODSS network. The goal of the RRN is to perform optical and radio observations of COMPTEL error boxes as soon after the burst as possible. We present results from the first two years of operation of this network.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00658626
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  • 8
    Electronic Resource
    Electronic Resource
    Performance of maize, beans and ginger as intercrops in Paulownia plantations in China (1997)
    Springer
    Agroforestry systems 39 (1997), S. 23-30 
    Details
    ISSN: 1572-9680
    Keywords: PAR transmission ; specific leaf weight ; tree proximity ; yield depression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Yield, morphology and specific leaf weight of summer crops maize, beans and ginger were studied in relation to tree proximity and PAR transmissivity in a 7-year old plantation of Paulownia elongata grown at a spacing of 15 m x 5 m in Eastern China. The yield of beans and maize was significantly reduced, compared to controls, at all positions relative to the trees. This yield depression was particularly marked at positions closest to the trees. Beans grown at 2 m from the trees had reduced height and specific leaf weight. These crops would yield more at wider tree row spacings. Ginger gave high yields when intercropped and is an ideal shade crop for these systems. Further research is required on optimisation using a bioeconomic approach. Further agronomic, physiological and biochemical work is required on ginger and other economic members of its family as these appear to have compatibility with dense agroforestry plantings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005938310106
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  • 9
    Electronic Resource
    Electronic Resource
    Comptel analysis of GRB 940217 (1995)
    Springer
    Astrophysics and space science 231 (1995), S. 153-156 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract COMPTEL on board CGRO has observed a very strong (S[〉 0.3 MeV] = 2.03 × 10−4 erg cm−2), complex, and long lasting (162 s) gamma-ray burst on February 17, 1994 (GRB 940217). Temporal fluctuations occur on timescales as short as 100 ms. Hard-to-soft spectral evolution has been observed during the burst emission and also within individual peaks. The photon spectra obtained within the 6 peaks can be modelled by single power law spectra and by broken power laws with break energies at around 1 MeV. The best-fit power law slopes vary between 1.1 and 3.5 throughout the event. The burst is located at [α 2000,δ 2000] = [29.5°, 3.8°] with a 3σ error radius of 0.9°. COMPTEL does not detect any significant “post-burst” emission (as reported by EGRET) at low energies (〈 30 MeV), and our upper limits are marginally consistent with the EGRET detections. Using high energy spectral and temporal information, distance limits to GRB 940217 have been derived.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00658606
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  • 10
    Electronic Resource
    Electronic Resource
    Spectral characterisation of gamma-ray bursts with COMPTEL and BATSE (1995)
    Springer
    Astrophysics and space science 231 (1995), S. 157-160 
    Details
    ISSN: 1572-946X
    Keywords: Gamma-ray bursts ; spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Although the earliest observed gamma-ray burst spectra were well described by thermal bremsstrahlung models, subsequent observations above 1 MeV showed the existence of high energy power law tails in ∼60% of events. In order to accurately characterise burst spectra, both the low energy turnover and the high energy tail must be accounted for. We have addressed this issue by jointly deconvolving spectra obtained by BATSE and COMPTEL onboard theCompton Observatory. We present preliminary results obtained by application of this method to the gamma-ray burst of February 17, 1994.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00658607
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