Turbidity sensor response to seasonal and spatial variability of suspended particle composition in open clear waters –(Portuguese continental shelf)

Mapping Intimacies ◽

10.5194/egusphere-egu21-7610 ◽

2021 ◽

Author(s):

Anabela Oliveira ◽

Ana Isabel Santos ◽

Rita Santos ◽

Nuno Zacarias

Keyword(s):

Continental Shelf ◽

Suspended Particle ◽

Gravimetric Method ◽

Suspended Sediments ◽

Sample Collection ◽

X Ray Diffraction ◽

Concentration Data ◽

In Situ Calibration ◽

Signal Sensitivity

As part of AQUIMAR project (MAR2020 n&#186; MAR-02.01.01-FEAMP-017 &#8211; AQUIMAR &#8211; Carateriza&#231;&#227;o geral das &#225;reas aqu&#237;colas para estabelecimento de culturas marinhas), intensive CTD surveys and turbidity/concentration data were collected in four cruises along the Portuguese continental shelf (30-200m depth), in 5 aquaculture areas from 2018 to 2020. In-situ calibration of the turbidity sensor (Seapoint Turbidity Meter) was done using the traditional gravimetric method of suspended sediments concentration (SSC) determination with water sampling and filtering. The obtained FTU/SSC relations resulted in correlations in the order of R2=70-80% for all considered surveys.Measured turbidity and concentration values, were generally very low (<2 FTU and <2 mg/l) for all measuring periods, however variations of the FTU/SSC sensitivity between the different areas indicate that significant variations of suspended matter composition exist throughout the Portuguese continental shelf.This study aims to understand the seasonal and spatial variations of the turbidity signal sensitivity to SSC. To this end, a closer look will be given to samples collected during two contrasting seasonal periods (spring and late autumn 2019), as well as to the general water column structure at the time of the sample collection. Additionally, results from X-Ray diffraction analysis performed in some of the filtered samples will be used to better understand the variations of the suspended sediment composition in open clear waters. The mineralogical signal shows a dominance of clay minerals in suspension (mean 83%) and calcite (mean 10%), reflecting the detritic and organic fraction of SSC, respectively.

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A versatile and reproducible automatic injection system for liquid standard introduction: application to in-situ calibration

Atmospheric Measurement Techniques ◽

10.5194/amt-4-1937-2011 ◽

2011 ◽

Vol 4 (9) ◽

pp. 1937-1942 ◽

Cited By ~ 16

Author(s):

G. Isaacman ◽

N. M. Kreisberg ◽

D. R. Worton ◽

S. V. Hering ◽

A. H. Goldstein

Keyword(s):

Effective Means ◽

Injection System ◽

Sample Collection ◽

Chemical Complexity ◽

Liquid Standard ◽

In Situ Calibration ◽

Relative Standard ◽

Multiple Sample ◽

Trace Compounds

Abstract. The quantitation of trace organic compounds in ambient organic aerosol is difficult due to the chemical complexity of these mixtures, but is needed to provide insight into their sources and formation processes. Compound-level characterization of organic aerosols is typically performed through sample collection followed by gas or liquid chromatography. With these methods, introduction of liquid standards has long been used as an effective means of quantifying trace compounds, but automating this technique for use with in-situ instrumentation has not previously been achieved. Here we develop an automatic injection system (AutoInject) for the introduction of liquids into a custom collection and analysis cell for improved quantitation in chromatographic measurements. The system consists of chilled reservoirs containing liquid standards from which a sample loop is loaded and then injected into the cell. The AutoInject is shown to be reproducible over 106 injections with a relative standard deviation of 1.5%, and have negligible injection-to-injection carryover. A 6-port selector allows injection of different liquid standards separately or simultaneously. Additionally, automatic injection of multiple sample loops is shown to generate a linear multi-point calibration curve. Tests conducted in this work focus on use with the Thermal desorption Aerosol Gas chromatograph (TAG), but the flexibility of the system allows it to be used for a variety of applications.

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A versatile and reproducible automatic injection system for liquid standard introduction: application to in-situ calibration

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-4-3233-2011 ◽

2011 ◽

Vol 4 (3) ◽

pp. 3233-3249

Author(s):

G. Isaacman ◽

N. M. Kreisberg ◽

D. R. Worton ◽

S. V. Hering ◽

A. H. Goldstein

Keyword(s):

Effective Means ◽

Injection System ◽

Sample Collection ◽

Chemical Complexity ◽

Liquid Standard ◽

In Situ Calibration ◽

Relative Standard ◽

Multiple Sample ◽

Trace Compounds

Abstract. The quantitation of trace organic compounds in ambient organic aerosol is difficult due to the chemical complexity of these mixtures, but is needed to provide insight into their sources and formation processes. Compound-level characterization of organic aerosols is typically performed through sample collection followed by gas or liquid chromatography. With these methods, introduction of liquid standards has long been used as an effective means of quantifying trace compounds, but automating this technique for use with in-situ instrumentation has not previously been achieved. Here we develop an automatic injection system (AutoInject) for the introduction of liquids into a custom collection and analysis cell for improved quantitation in chromatographic measurements. The system consists of chilled reservoirs containing liquid standards from which a sample loop is loaded and then injected into the cell. The AutoInject is shown to have reproducibility over 106 injections with a relative standard deviation of 1.5 %, and have negligible injection-to-injection carryover. A 6-port selector allows injection of different liquid standards separately or simultaneously. Additionally, automatic injection of multiple sample loops is shown to generate a linear multi-point calibration curve. Tests conducted in this work focus on use with the Thermal desorption Aerosol Gas chromatograph (TAG), but the flexibility of the system allows it to be used for a variety of applications.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173479 ◽

1990 ◽

Vol 48 (4) ◽

pp. 68-69

Author(s):

J. T. Sizemore ◽

D. G. Schlom ◽

Z. J. Chen ◽

J. N. Eckstein ◽

I. Bozovic ◽

...

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Critical Currents ◽

Unit Cell ◽

X Ray Diffraction ◽

Cell Axis ◽

Transmission Electron ◽

Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

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Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017788x ◽

1990 ◽

Vol 48 (4) ◽

pp. 950-951

Author(s):

G. A. Bertero ◽

W.H. Hofmeister ◽

N.D. Evans ◽

J.E. Wittig ◽

R.J. Bayuzick

Keyword(s):

Electron Microscopy ◽

Amorphous Structure ◽

Sulphuric Acid Solution ◽

X Ray Diffraction ◽

High Fracture ◽

Transmission Electron ◽

Xrd Techniques ◽

Rapidly Solidified ◽

Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

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