scholarly journals In situ quantification of bioturbation using time-lapse fluorescent sediment profile imaging (f-SPI), luminophore tracers and model simulation

2004 ◽  
Vol 271 ◽  
pp. 1-12 ◽  
Author(s):  
M Solan ◽  
BD Wigham ◽  
IR Hudson ◽  
R Kennedy ◽  
CH Coulon ◽  
...  
Keyword(s):  
Model Simulation ◽  
Time Lapse ◽  
Sediment Profile

scholarly journals Simultaneous quantification of in situ infaunal activity and pore-water metal concentrations: establishment of benthic ecosystem process-function relations

2012 ◽  
Vol 9 (7) ◽  
pp. 8541-8570
Author(s):  
L. R. Teal ◽  
E. R. Parker ◽  
M. Solan
Keyword(s):  
Statistical Modelling ◽  
Time Lapse ◽  
Simulation Modelling ◽  
Ecosystem Process ◽  
Sediment Profile ◽  
Infaunal Community ◽  
Spatio Temporal ◽  
Mechanistic Basis ◽  
Abiotic And Biotic Factors

Abstract. The relative contributions that species assemblages, abiotic variables, and their interactions with one another, make to ecosystem properties are recognised but are seldom considered simultaneously, within context, and at the appropriate spatio-temporal scales. Here, we combine fluorescent time-lapse sediment profile imaging (f-SPI) and diffusion gradient thin gels (DGT) to examine, in situ, the link between an important benthic ecosystem process (bioturbation) and ecosystem functioning (trace metal cycling). We show that the mechanistic basis of how the infaunal community mediate Fe and Mn cycles is difficult to reconcile because of the spatio-temporal differences between particle and porewater mixing. This mismatch means that the consideration of these mechanistic processes in isolation is likely to limit our interpretative capacity of how infaunal communities mediate various biogeochemical processes in the natural environment. Moreover, the combination of multiple technologies, process based simulation modelling and generalised additive statistical modelling achieved here, emphasises the importance of simultaneously considering additional factors that influence benthic chemistry, in particular bioirrigation and tidal flushing of the sediment profile. Our findings highlight a pressing need to determine how the relative importance of multiple abiotic and biotic factors act in concert to alter major biogeochemical pathways across a variety of contexts and habitats.

scholarly journals Coupling bioturbation activity to metal (Fe and Mn) profiles in situ

2013 ◽  
Vol 10 (4) ◽  
pp. 2365-2378 ◽  
Author(s):  
L. R. Teal ◽  
E. R. Parker ◽  
M. Solan
Keyword(s):  
Statistical Modelling ◽  
Time Lapse ◽  
Simulation Modelling ◽  
Sediment Profile ◽  
Infaunal Community ◽  
In Situ Data ◽  
Fe And Mn ◽  
Spatio Temporal ◽  
Mechanistic Basis

Abstract. The relative contributions that species assemblages, abiotic variables, and their interactions with one another make to ecosystem properties are recognised but are seldom considered simultaneously, within context, and at the appropriate spatio-temporal scales. Here, we combine fluorescent time-lapse sediment profile imaging (f-SPI) and diffusion gradient thin gels (DGT) to examine, in situ, the link between an important benthic ecosystem process (bioturbation) and the availability (profiles) of Fe and Mn. Whilst the combination of these methodologies (fg-SPI) was successful in gathering high-resolution in situ data of bioturbation activity and Fe/Mn profiles simultaneously, we show that the mechanistic basis of how the infaunal community mediate Fe and Mn is difficult to reconcile because of the spatio-temporal differences between particle and porewater mixing. This mismatch means that the consideration of these mechanistic processes in isolation is likely to limit our interpretative capacity of how infaunal communities mediate various biogeochemical processes in the natural environment. Moreover, the combination of multiple technologies, process based simulation modelling and generalised additive statistical modelling achieved here, emphasises the importance of simultaneously considering additional factors that influence benthic chemistry, in particular bioirrigation and tidal flushing of the sediment profile. Our findings highlight a pressing need to determine how the relative importance of multiple abiotic and biotic factors act in concert to alter major biogeochemical pathways across a variety of contexts and habitats.

scholarly journals Long-term O<sub>3</sub>–precursor relationships in Hong Kong: field observation and model simulation

2017 ◽  
Vol 17 (18) ◽  
pp. 10919-10935 ◽  
Author(s):  
Yu Wang ◽  
Hao Wang ◽  
Hai Guo ◽  
Xiaopu Lyu ◽  
Hairong Cheng ◽  
...  
Keyword(s):  
Hong Kong ◽  
Model Simulation ◽  
Ground Level ◽  
Effective Control ◽  
Photochemical Pollution ◽  
Mixing Ratios ◽  
The Past ◽  
Total Volatile Organic Compounds

Abstract. Over the past 10 years (2005–2014), ground-level O3 in Hong Kong has consistently increased in all seasons except winter, despite the yearly reduction of its precursors, i.e. nitrogen oxides (NOx =  NO + NO2), total volatile organic compounds (TVOCs), and carbon monoxide (CO). To explain the contradictory phenomena, an observation-based box model (OBM) coupled with CB05 mechanism was applied in order to understand the influence of both locally produced O3 and regional transport. The simulation of locally produced O3 showed an increasing trend in spring, a decreasing trend in autumn, and no changes in summer and winter. The O3 increase in spring was caused by the net effect of more rapid decrease in NO titration and unchanged TVOC reactivity despite decreased TVOC mixing ratios, while the decreased local O3 formation in autumn was mainly due to the reduction of aromatic VOC mixing ratios and the TVOC reactivity and much slower decrease in NO titration. However, the decreased in situ O3 formation in autumn was overridden by the regional contribution, resulting in elevated O3 observations. Furthermore, the OBM-derived relative incremental reactivity indicated that the O3 formation was VOC-limited in all seasons, and that the long-term O3 formation was more sensitive to VOCs and less to NOx and CO in the past 10 years. In addition, the OBM results found that the contributions of aromatics to O3 formation decreased in all seasons of these years, particularly in autumn, probably due to the effective control of solvent-related sources. In contrast, the contributions of alkenes increased, suggesting a continuing need to reduce traffic emissions. The findings provide updated information on photochemical pollution and its impact in Hong Kong.

Determining optimum wave velocity from sparse CMP automatically by coupling POCS interpolation and NMO correction: application to array antenna GPR data collected during in-situ infiltration test

2021 ◽  
Author(s):  
Koki Oikawa ◽  
Hirotaka Saito ◽  
Seiichiro Kuroda ◽  
Kazunori Takahashi
Keyword(s):  
Wave Velocity ◽  
Convex Sets ◽  
Numerical Study ◽  
Sand Dunes ◽  
Time Lapse ◽  
Array Antenna ◽  
Velocity Analysis ◽  
Nmo Correction ◽  
Infiltration Experiment

&lt;p&gt;As an array antenna ground penetrating radar (GPR) system electronically switches any antenna combinations sequentially in milliseconds, multi-offset gather data, such as common mid-point (CMP) data, can be acquired almost seamlessly. However, due to the inflexibility of changing the antenna offset, only a limited number of scans can be obtained. The array GPR system has been used to collect time-lapse GPR data, including CMP data during the field infiltration experiment (Iwasaki et al., 2016). CMP data obtained by the array GPR are, however, too sparse to obtain reliable velocity using a standard velocity analysis, such as semblance analysis. We attempted to interpolate the sparse CMP data based on projection onto convex sets (POCS) algorithm (Yi et al., 2016) coupled with NMO correction to automatically determine optimum EM wave velocity. Our previous numerical study showed that the proposed method allows us to determine the EM wave velocity during the infiltration experiment.&lt;/p&gt;&lt;p&gt;The main objective of this study was to evaluate the performance of the proposed method to interpolate sparse array antenna GPR CMP data collected during the in-situ infiltration experiment at Tottori sand dunes. The interpolated CMP data were then used in the semblance analysis to determine the EM wave velocity, which was further used to compute the infiltration front depth. The estimated infiltration depths agreed well with independently obtained depths. This study demonstrated the possibility of developing an automatic velocity analysis based on POCS interpolation coupled with NMO correction for sparse CMP collected with array antenna GPR.&lt;/p&gt;

scholarly journals An instrumented sample holder for time-lapse microtomography measurements of snow under advective airflow

2014 ◽  
Vol 3 (2) ◽  
pp. 179-185 ◽  
Author(s):  
P. P. Ebner ◽  
S. A. Grimm ◽  
M. Schneebeli ◽  
A. Steinfeld
Keyword(s):  
Structural Changes ◽  
Time Lapse ◽  
Temperature Gradients ◽  
Sample Holder ◽  
Experimental Characterization ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Snow Samples

Abstract. An instrumented sample holder was developed for time-lapse microtomography of snow samples to enable in situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass transport properties were evaluated during a 4-day test run. This instrument allows the experimental characterization of metamorphism of snow undergoing structural changes with time.

In Situ Testing Using Synchrotron Radiation Computed Tomography in Materials Research

MRS Advances ◽  
2019 ◽  
Vol 4 (51-52) ◽  
pp. 2831-2841
Author(s):  
Xinchen Ni ◽  
Nathan K. Fritz ◽  
Brian L. Wardle
Keyword(s):  
Computed Tomography ◽  
Synchrotron Radiation ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Time Lapse ◽  
In Situ Testing ◽  
Temporal Dimension ◽  
Analysis Measurement ◽  
Materials Research

ABSTRACTHigh resolution (< 1 µm) computed tomography is an attractive tool in materials research due to its ability to non-destructively visualize the three-dimensional internal microstructures of the material. Recently, this technique has been further empowered by adding a fourth (temporal) dimension to study the time-lapse material response under load. Such studies are referred to as four-dimensional or in situ testing. In this snapshot review, we highlight three representative examples of in situ testing using synchrotron radiation computed tomography (SRCT) for composites failure analysis, measurement of local corrosion rate in alloys, and visualization and quantification of electrochemical reactions in lithium-ion batteries, as well as forward-looking integration of machine learning with in situ CT. Lastly, the future opportunities and challenges of in situ SRCT testing are discussed.

In-situ disintegration of egg white gels by pepsin and kinetics of nutrient release followed by time-lapse confocal microscopy

2020 ◽  
Vol 98 ◽  
pp. 105228 ◽  
Author(s):  
Geeshani Somaratne ◽  
Francoise Nau ◽  
Maria J. Ferrua ◽  
Jaspreet Singh ◽  
Aiqian Ye ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Nutrient Release ◽  
Time Lapse ◽  
Egg White ◽  
Kinetics Of

Cross‐borehole geoelectrical time‐lapse monitoring of in situ chemical oxidation and permeability estimation through induced polarization

2020 ◽  
Author(s):  
Thue Bording ◽  
Anders Kristian Kühl ◽  
Gianluca Fiandaca ◽  
Jørgen Fjeldsø Christensen ◽  
Anders Vest Christiansen ◽  
...  
Keyword(s):  
Time Lapse ◽  
Chemical Oxidation ◽  
Induced Polarization ◽  
In Situ Chemical Oxidation ◽  
Permeability Estimation
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