New type of time‐series sediment trap for the reliable collection of inorganic and organic trace chemical substances

1996 ◽  
Vol 67 (12) ◽  
pp. 4360-4363 ◽  
Author(s):  
K. Kremling ◽  
U. Lentz ◽  
B. Zeitzschel ◽  
D. E. Schulz‐Bull ◽  
J. C. Duinker
Keyword(s):  
Time Series ◽  
Sediment Trap ◽  
Chemical Substances ◽  
New Type ◽  
Organic Trace ◽  
Inorganic And Organic

scholarly journals Inorganic Radiocarbon in Time-Series Sediment Trap Samples: Implication of Seasonal Variation of 14C in the Upper Ocean

Radiocarbon ◽  
1996 ◽  
Vol 38 (3) ◽  
pp. 583-595 ◽  
Author(s):  
Makio C. Honda
Keyword(s):  
Time Series ◽  
Bering Sea ◽  
Sediment Trap ◽  
Seasonal Variability ◽  
Sea Of Okhotsk ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Sediment Traps ◽  
Upper Ocean ◽  
The Bering Sea

In order to verify sediment trap samples as indicators of upper ocean 14C concentrations, particulate inorganic radiocarbon (PICΔ14C) collected by time-series sediment traps in the Sea of Okhotsk and the Bering Sea was measured by accelerator mass spectrometry (AMS). All of the PICΔ14C measurements were < 0‰, in contrast to GEOSECS 14C data in the upper ocean from the northwestern North Pacific. This difference is attributed to the upwelling of deepwater that contains low Δ14C of dissolved inorganic carbon (DICΔ14C) and to the decrease over time of surface DICΔ14C owing to the decrease of atmospheric Δ14C values. In addition, PICΔ14C values showed significant seasonal variability: PICΔ14C collected in the fall was the greatest (-22‰ on average), whereas PICΔ14C collected in winter showed an average minimum of −48‰. It is likely that this difference was caused by changes in mixed layer thickness. Although some uncertainties remain, further study on PICΔ14C will enable us to estimate seasonal variability in DICΔ14C and air-sea CO2 exchange rate.

Variations in the composition of particulate organic matter in a time-series sediment trap

1983 ◽  
Vol 13 (3) ◽  
pp. 181-194 ◽  
Author(s):  
Cindy Lee ◽  
Stuart G. Wakeham ◽  
John W. Farrington
Keyword(s):  
Time Series ◽  
Organic Matter ◽  
Particulate Organic Matter ◽  
Sediment Trap

scholarly journals A Time Series of Water Column Distributions and Sinking Particle Flux of Pseudo-Nitzschia and Domoic Acid in the Santa Barbara Basin, California

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 480 ◽  
Author(s):  
Blaire Umhau ◽  
Claudia Benitez-Nelson ◽  
Clarissa Anderson ◽  
Kelly McCabe ◽  
Christopher Burrell
Keyword(s):  
Time Series ◽  
Water Column ◽  
Sediment Trap ◽  
Domoic Acid ◽  
Particle Flux ◽  
Sediment Traps ◽  
Benthic Organisms ◽  
Santa Barbara ◽  
Santa Barbara Basin ◽  
Potential Source

Water column bulk Pseudo-nitzschia abundance and the dissolved and particulate domoic acid (DA) concentrations were measured in the Santa Barbara Basin (SBB), California from 2009–2013 and compared to bulk Pseudo-nitzschia cell abundance and DA concentrations and fluxes in sediment traps moored at 147 m and 509 m. Pseudo-nitzschia abundance throughout the study period was spatially and temporally heterogeneous (<200 cells L−1 to 3.8 × 106 cells L−1, avg. 2 × 105 ± 5 × 105 cells L−1) and did not correspond with upwelling conditions or the total DA (tDA) concentration, which was also spatially and temporally diverse (<1.3 ng L−1 to 2.2 × 105 ng L−1, avg. 7.8 × 103 ± 2.2 × 104 ng L−1). We hypothesize that the toxicity is likely driven in part by specific Pseudo-nitzschia species as well as bloom stage. Dissolved (dDA) and particulate (pDA) DA were significantly and positively correlated (p < 0.01) and both comprised major components of the total DA pool (pDA = 57 ± 35%, and dDA = 42 ± 35%) with substantial water column concentrations (>1000 cells L−1 and tDA = 200 ng L−1) measured as deep as 150 m. Our results highlight that dDA should not be ignored when examining bloom toxicity. Although water column abundance and pDA concentrations were poorly correlated with sediment trap Pseudo-nitzschia abundance and fluxes, DA toxicity is likely associated with senescent blooms that rapidly sink to the seafloor, adding another potential source of DA to benthic organisms.

Study on Trispectrum Characteristics of MR Damper in Vibration Processes

2011 ◽  
Vol 211-212 ◽  
pp. 285-289
Author(s):  
Fu Sen Wu ◽  
Yi Jian Huang ◽  
Shan Xu
Keyword(s):  
Time Series ◽  
Working Conditions ◽  
Dynamic Characteristics ◽  
Mr Damper ◽  
Ar Model ◽  
Vibration Process ◽  
New Type ◽  
Non Gaussian ◽  
Working Parameters ◽  
Optimum Working

In order to find out a new type of MR damper for block making machine, the signals of displacement in the vibration process during the test are collected and the time series AR model of trispectrum for analyzing the dynamic characteristics of the MR damper is built. It turns out that , in different working conditions, slices of trispectrum are applied to obtain the signal’s non-Gaussian, nonlinear amplitude-frequency characteristics which are very important for us to select the optimum working parameters of the MR damper.

scholarly journals Links between surface productivity and deep ocean particle flux at the Porcupine Abyssal Plain sustained observatory

2015 ◽  
Vol 12 (19) ◽  
pp. 5885-5897 ◽  
Author(s):  
H. Frigstad ◽  
S. A. Henson ◽  
S. E. Hartman ◽  
A. M. Omar ◽  
E. Jeansson ◽  
...  
Keyword(s):  
Time Series ◽  
Particle Tracking ◽  
Sediment Trap ◽  
Source Region ◽  
Correlation Coefficients ◽  
Deep Ocean ◽  
Abyssal Plain ◽  
New Production ◽  
Export Ratio ◽  
Surface Productivity

Abstract. In this study we present hydrography, biogeochemistry and sediment trap observations between 2003 and 2012 at Porcupine Abyssal Plain (PAP) sustained observatory in the Northeast Atlantic. The time series is valuable as it allows for investigation of the link between surface productivity and deep ocean carbon flux. The region is a perennial sink for CO2, with an average uptake of around 1.5 mmol m−2 day−1. The average monthly drawdowns of inorganic carbon and nitrogen were used to quantify the net community production (NCP) and new production. Seasonal NCP and new production were found to be 4.57 ± 0.85 mol C m−2 and 0.37 ± 0.14 mol N m−2, respectively. The C : N ratio was high (12) compared to the Redfield ratio (6.6), and the production calculated from carbon was higher than production calculated from nitrogen, which is indicative of carbon overconsumption. The export ratio and transfer efficiency were 16 and 4 %, respectively, and the site thereby showed high flux attenuation. Particle tracking was used to examine the source region of material in the sediment trap, and there was large variation in source regions, both between and within years. There were higher correlations between surface productivity and export flux when using the particle-tracking approach, than by comparing with the mean productivity in a 100 km box around the PAP site. However, the differences in correlation coefficients were not significant, and a longer time series is needed to draw conclusions on applying particle tracking in sediment trap analyses.

Parametric Identification of Systems With Dry Friction and Nonlinear Stiffness Using a Time Series Model

1996 ◽  
Vol 118 (2) ◽  
pp. 252-263 ◽  
Author(s):  
Q. Chen ◽  
G. R. Tomlinson
Keyword(s):  
Time Series ◽  
Dry Friction ◽  
Coulomb Friction ◽  
System Parameter ◽  
Parametric Identification ◽  
Time Series Model ◽  
Viscous Damping ◽  
Nonlinear Stiffness ◽  
Transform Method ◽  
New Type

A new type of time series model, the AVD model which accommodates the Acceleration, Velocity and Displacement simultaneously, has been used to estimate the characteristics of nonlinear single and multi-degree of freedom systems with dry Coulomb friction, viscous damping and nonlinear stiffness. Numerical results via simulation are compared with those from a Fourier transform method, which suggests that the AVD model is a powerful technique for nonlinear system parameter identification.

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