scholarly journals Bio-Optical Modeling in a Tropical Hypersaline Lagoon Environment

10.5772/61869 ◽  
2016 ◽  
Author(s):  
Igor Ogashawara ◽  
Marcelo P. Curtarelli ◽  
Carlos A.S. Araujo ◽  
José L. Stech
Keyword(s):  
Optical Modeling ◽  
Hypersaline Lagoon ◽  
Lagoon Environment

scholarly journals Hyaluronan orders water molecules in its nanoscale extended hydration shells

2021 ◽  
Vol 7 (10) ◽  
pp. eabf2558
Author(s):  
J. Dedic ◽  
H. I. Okur ◽  
S. Roke
Keyword(s):  
Second Harmonic ◽  
Hydration Shell ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Flexible Chain ◽  
Optical Modeling ◽  
Hydration Shells ◽  
Second Harmonic Scattering ◽  
Nuclear Quantum Effects ◽  
Extracellular Environment

Hyaluronan (HA) is an anionic, highly hydrated bio-polyelectrolyte found in the extracellular environment, like the synovial fluid between joints. We explore the extended hydration shell structure of HA in water using femtosecond elastic second-harmonic scattering (fs-ESHS). HA enhances orientational water-water correlations. Angle-resolved fs-ESHS measurements and nonlinear optical modeling show that HA behaves like a flexible chain surrounded by extended shells of orientationally correlated water. We describe several ways to determine the concentration-dependent size and shape of a polyelectrolyte in water, using the amount of water oriented by the polyelectrolyte charges as a contrast agent. The spatial extent of the hydration shell is determined via temperature-dependent measurements and can reach up to 475 nm, corresponding to a length of 1600 water molecules. A strong isotope effect, stemming from nuclear quantum effects, is observed when light water (H2O) is replaced by heavy water (D2O), amounting to a factor of 4.3 in the scattered SH intensity.

Natural and anthropogenic effects on microplastic distribution in a hypersaline lagoon

2021 ◽  
Vol 776 ◽  
pp. 145803
Author(s):  
Mariana Quesadas-Rojas ◽  
Cecilia Enriquez ◽  
Arnoldo Valle-Levinson
Keyword(s):  
Anthropogenic Effects ◽  
Hypersaline Lagoon

Optical modeling and electrical properties of cadmium oxide nanofilms: Developing a meta–heuristic calculation process model

2015 ◽  
Vol 117 (13) ◽  
pp. 135303 ◽  
Author(s):  
Ali Abdolahzadeh Ziabari ◽  
A. H. Refahi Sheikhani ◽  
Reza Vatani Nezafat ◽  
Kasra Monsef Haghighidoust
Keyword(s):  
Electrical Properties ◽  
Process Model ◽  
Cadmium Oxide ◽  
Optical Modeling ◽  
Calculation Process

An overview of WFIRST/AFTA coronagraph optical modeling

2015 ◽  
Author(s):  
John Krist ◽  
Bijan Nemati ◽  
Hanying Zhou ◽  
Erkin Sidick
Keyword(s):  
Optical Modeling

Optical data collection and bio-optical modeling in Northern Adriatic Sea

1999 ◽  
Author(s):  
Luigi Alberotanza ◽  
G. Ferro Milone ◽  
Giuliana Profeti ◽  
C. Ramasco
Keyword(s):  
Data Collection ◽  
Adriatic Sea ◽  
Optical Data ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Optical Modeling

scholarly journals Behaviour of Metal(loid)s at the Sediment-Water Interface in an Aquaculture Lagoon Environment (Grado Lagoon, Northern Adriatic Sea, Italy)

2021 ◽  
Vol 11 (5) ◽  
pp. 2350
Author(s):  
Elisa Petranich ◽  
Matteo Crosera ◽  
Elena Pavoni ◽  
Jadran Faganeli ◽  
Stefano Covelli
Keyword(s):  
Sediment Cores ◽  
Fish Farm ◽  
Trophic Chain ◽  
Water Interface ◽  
Northern Adriatic Sea ◽  
Overlying Water ◽  
Northern Adriatic ◽  
In Situ Experiments ◽  
Diffusive Fluxes ◽  
Lagoon Environment

The cycling of metal(loid)s at the sediment–water interface (SWI) was evaluated at two selected sites (VN1 and VN3) in an active fish farm in the Grado Lagoon (Northern Adriatic, Italy). In situ experiments using a transparent benthic chamber and the collection of short sediment cores were performed, to investigate the behavior of metal(loid)s in the solid (sediments) and dissolved (porewaters) phases. Total and labile concentration of metal(loid)s were also determined in sediments, to quantify their potential mobility. Comparable total concentrations were found at both sites, excluding As, Mn, Pb and V, which were higher at VN3. Metal(loid) porewater profiles showed a diagenetic sequence and a close dependence with redox (suboxic/anoxic) conditions in the surface sediments. Positive diffusive fluxes along with benthic fluxes, particularly at the more oxic site, VN1, were found for almost all metal(loid)s, indicating their tendency to migrate towards the overlying water column. Despite sediments at two sites exhibiting high total metal(loid) concentrations and moderate effluxes at the SWI, the results suggest that they are hardly remobilized from the sediments. Recycling of metal(loid)s from the SWI would not constitute a threat for the aquatic trophic chain in the fish farm.

Hydrographic Processes in a Tropical Coastal Lagoon on Western Bay of Bengal

2021 ◽  
Author(s):  
Rabindra Kumar Sahoo ◽  
Sourav Sil ◽  
Samiran Mandal ◽  
Subhasis Pradhan ◽  
Sanjiba Kumar Baliarsingh ◽  
...  
Keyword(s):  
Central Region ◽  
Coastal Lagoon ◽  
Bay Of Bengal ◽  
Saline Water ◽  
Western Boundary ◽  
Chilika Lagoon ◽  
Thermal Inversion ◽  
Tropical Coastal Lagoon ◽  
Lagoon Environment ◽  
Vertical Variability

Abstract In this article, hydrographic processes of a tropical coastal lagoon is studied that control inherent biological mechanisms of the lagoon environment. Realizing the interest of environmentalists over physio-chemical studies of a wetland tropical wetland system on the western boundary of the Bay of Bengal, a high-resolution intensive vertical hydrographic field campaign was carried during monsoon to uncover peculiarity in vertical hydrographic processes that was long-awaited to address many environmental issues. Vertical hydrographic profiles on spatio-temporal scale were made at nine stations in a zonal direction of the Chilika lagoon system. Results of vertical variability of salinity showed the presence of higher saline water over less saline water in the central-western region. The higher and lower water temperature in the western and eastern parts of the lagoon, respectively, indicated temperature dipole between the two regions. The encapsulation of water mass having higher temperature by the water of lower temperature at the central region resulted evolution of thermal inversion. The highest dissolved oxygen concentration was observed in the sub-surface layers of the western part of the lagoon. However, a layer of near-hypoxia occurred below 1.5 m depth in the central region. This study proposes comprehensive inter-seasonal studies to address the vertical variability of biogeochemical parameters and the fate of organic flux.

Optical modeling for millimeter and submillimeter-wave systems

2008 ◽  
Author(s):  
John A. Murphy ◽  
Marcin L. Gradziel ◽  
Creidhe O'Sullivan ◽  
Tully Peacocke ◽  
Neil Trappe ◽  
...  
Keyword(s):  
Submillimeter Wave ◽  
Optical Modeling
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