Dissolved organic carbon concentrations, amino sugar concentrations and highly significantly correlating FT-ICR mass peak magnitudes obtained from solid phase extracted marine dissolved organic matter during POLARSTERN cruise ANT-XXV/1

Dissolved organic matter (DOM) was extracted with solid phase extraction (SPE) from 137 water samples from different climate zones and different depths along an Eastern Atlantic Ocean transect. The extracts were analyzed with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI). D14C analyses were performed on subsamples of the SPE-DOM. In addition, the amount of dissolved organic carbon was determined for all water and SPE-DOM samples as well as the yield of amino sugars for selected samples. Linear correlations were observed between the magnitudes of 43% of the FT-ICR mass peaks and the extract D14C values. Decreasing SPE-DOM D14C values went along with a shift in the molecular composition to higher average masses (m/z) and lower hydrogen/carbon (H/C) ratios. The correlation was used to model the SPE-DOM D14C distribution for all 137 samples. Based on single mass peaks a degradation index was developed to compare the degradation state of marine SPE-DOM samples analyzed with FT-ICR MS. A correlation between D14C, degradation index, DOC values and amino sugar yield supports that SPE-DOM analyzed with FT-ICR MS reflects trends of bulk DOM. A relative mass peak magnitude ratio was used to compare aged SPE-DOM and fresh SPE-DOM regarding single mass peaks. The magnitude ratios show a continuum of different reactivities for the single compounds. Only few of the compounds present in the FT-ICR mass spectra are expected to be highly degraded in the oldest water masses of the Pacific Ocean. All other compounds should persist partly thermohaline circulation. Prokaryotic (bacterial) production, transformation and accumulation of this very stable DOM occurs probably primarily in the upper ocean. This DOM is an important contribution to very old DOM, showing that production and degradation are dynamic processes.

Siuslaw National Forest (N.F.), Mary's Peak Planning Unit : environmental impact statement.

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Sketches of Chocorua Peak?

[From Jasper Cropsey Sketch book, 1855-1856]

Chocorua Peak

[From Jasper Cropsey Sketch book, 1855-1856]

IFR altitude usage peak day 1960 /

Cover title.

The peak of the load; the waiting months on the hilltop from the entrance of the Stars and Stripes to the second victory of the Marne.

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Effect of rate of change of slip on the peak braking coefficient of passenger car tires. Technical report.

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Absolute photometry of the light of the night sky ; the zenith intensity of Haleakala (latitude N 20.7 degrees) and at Fritz Peak (latitude N 39.9 degrees) /

Includes bibliography.

Mechanisms for increasing the peak heat flux in boiling saturated water at atmospheric pressure; a report for National Science Foundation, Grant GP 788.

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Truck noise-I : peak a-weighted sound levels due to truck tires : final report /

Photocopy. Springfield, Va. : Reproduced by National Technical Information Service, [197-]. -- 24O p. on 240 leaves.