Determination of sub‐bottom sediment properties and their spatial distributions from chirp sonar data.

1996 ◽  
Vol 99 (4) ◽  
pp. 2451-2457 ◽  
Author(s):  
Altan Turgut
Keyword(s):  
Bottom Sediment ◽  
Spatial Distributions ◽  
Sediment Properties ◽  
Chirp Sonar

scholarly journals Determination of dissolved nitric oxide in coastal waters of the Yellow Sea off Qingdao

2017 ◽  
Author(s):  
Chun-Ying Liu ◽  
Wei-Hua Feng ◽  
Ye Tian ◽  
Gui-Peng Yang ◽  
Pei-Feng Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Detection Limit ◽  
Coastal Waters ◽  
Yellow Sea ◽  
The Yellow Sea ◽  
No Production ◽  
Spatial Distributions ◽  
Production Rates ◽  
Temporal And Spatial

Abstract. We developed a new method for the determination of dissolved nitric oxide (NO) in discrete seawater samples based on a combination of a purge-and-trap set-up and fluorometric detection of NO. 2,3-diaminonaphthalene (DAN) reacts with NO in seawater to form the highly fluorescent 2,3-naphthotriazole (NAT). The fluorescence intensity was linear for NO concentrations in the range from 0.14 nmol L−1 to 19 nmol L−1. We determined a detection limit of 0.068 nmol L−1, an average recovery coefficient of 83.8 % (80.2–90.0 %), and a relative standard deviation of ±7.2 %. With our method we determined for the first time the temporal and spatial distributions of NO surface concentrations in coastal waters of the Yellow Sea off Qingdao and in Jiaozhou Bay during a cruise in November 2009. The concentrations of NO varied from below the detection limit to 0.50 nmol L−1 with an average of 0.26 ± 0.14 nmol L−1. NO surface concentrations were generally enhanced significantly during daytime implying that NO formation processes such as NO2− photolysis are much higher during daytime than chemical NO consumption which, in turn, lead to a significant decrease of NO concentrations during nighttime. In general, NO surface concentrations and measured NO production rates were higher compared to previously reported measurements. This might be caused by the high NO2− surface concentrations encountered during the cruise. Moreover, additional measurements of NO production rates implied that the occurrence of particles and a temperature increase can enhance NO production rates. With the method introduced here we have a reliable and comparably easy to use method at hand to measure oceanic NO surface concentrations which can be used to decipher both its temporal and spatial distributions as well as its biogeochemical pathways in the oceans.

Determination of Spatial Distributions of Plasma Parameters of a Compact Magnetron Discharge

2019 ◽  
Vol 82 (10) ◽  
pp. 1376-1381
Author(s):  
V. M. Gradov ◽  
A. M. Zimin ◽  
S. V. Serushkin ◽  
I. A. Zemtsov
Keyword(s):  
Spatial Distributions ◽  
Plasma Parameters ◽  
Magnetron Discharge

First results on determination of chlorophill A and its derivatives in the system of trapped sedimentary material–fluffy layer–bottom sediment of the Caspian Sea

2016 ◽  
Vol 467 (1) ◽  
pp. 284-288 ◽  
Author(s):  
M. D. Kravchishina ◽  
A. P. Lisitzin ◽  
A. Yu. Lein ◽  
V. N. Lukashin ◽  
A. N. Novigatsky ◽  
...  
Keyword(s):  
Bottom Sediment ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
First Results
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