scholarly journals Response to Anonymous Referee #2 on “Holocene phototrophic community and anoxia dynamics in meromictic Lake Jaczno (NE Poland) using high-resolution hyperspectral imaging and HPLC data” by Stamatina Makri et al.

2020 ◽  
Author(s):  
Stamatina Makri
Keyword(s):  
High Resolution ◽  
Hyperspectral Imaging ◽  
Meromictic Lake ◽  
Ne Poland ◽  
Phototrophic Community ◽  
Hplc Data

scholarly journals Holocene phototrophic community and anoxia dynamics in meromictic Lake Jaczno (NE Poland) using high-resolution hyperspectral imaging and HPLC data

2020 ◽  
Author(s):  
Stamatina Makri ◽  
Andrea Lami ◽  
Luyao Tu ◽  
Wojciech Tylmann ◽  
Hendrik Vogel ◽  
...  
Keyword(s):  
High Resolution ◽  
Human Impact ◽  
Hyperspectral Imaging ◽  
Environmental Concern ◽  
Human Impacts ◽  
Meromictic Lake ◽  
Purple Sulfur Bacteria ◽  
Ne Poland ◽  
Sulfur Bacteria ◽  
Phototrophic Community

Abstract. Global spread of hypoxia and altered mixing regimes in freshwater systems is a growing major environmental concern. Climate change and human impact are expected to increasingly deteriorate aquatic ecosystems. The study of processes and drivers of such changes in the past provides a great asset for prevention and remediation in the future. We used a multi-proxy approach combining high-resolution Hyperspectral Imaging (HSI) pigment data, with specific HPLC chlorophylls and carotenoids to examine Holocene trophic state changes and anoxia evolution in meromictic Lake Jaczno, NE Poland. A redundancy analysis RDA including pollen-inferred vegetation cover, temperature and human impacts provides insight into specific conditions and drivers of changing trophic and redox states in the lake. Anoxic and sulfidic conditions established in Lake Jaczno after initial basin infilling 9500 years ago. Until 6700 cal BP, lake trophy was relatively low, water turbidity was high, and green sulfur bacteria (GSB) were abundant within the phototrophic community, suggesting a deep oxic–anoxic boundary and weak stratification. The period between 6700–500 cal BP is characterized by constantly increasing lake production and a gradual shift from GSB to purple sulfur bacteria (PSB), suggesting a shallower oxic–anoxic boundary and pronounced stratification. Yet, the presence of spheroidene and speroidenone in the sediments indicates intermittent anoxia. After 500 cal BP, increasing human impact, deforestation and intensive agriculture promoted lake eutrophication, with a shift to PSB dominance and establishment of permanent anoxia and meromixis. Our study unambiguously documents the legacy of human impact on processes determining eutrophication and anoxia.

scholarly journals Holocene phototrophic community and anoxia dynamics in meromictic Lake Jaczno (NE Poland) using high-resolution hyperspectral imaging and HPLC data

2021 ◽  
Vol 18 (5) ◽  
pp. 1839-1856
Author(s):  
Stamatina Makri ◽  
Andrea Lami ◽  
Luyao Tu ◽  
Wojciech Tylmann ◽  
Hendrik Vogel ◽  
...  
Keyword(s):  
High Resolution ◽  
Human Impact ◽  
Hyperspectral Imaging ◽  
Environmental Concern ◽  
Human Impacts ◽  
Meromictic Lake ◽  
Purple Sulfur Bacteria ◽  
Ne Poland ◽  
Sulfur Bacteria ◽  
Phototrophic Community

Abstract. Global spread of hypoxia and less frequent mixing in lakes is a major growing environmental concern. Climate change and human impact are expected to increasingly deteriorate aquatic ecosystems. The study of processes and drivers of such changes in the past provides a great asset for prevention and remediation in the future. We used a multiproxy approach combining high-resolution bulk pigment data measured by hyperspectral imaging (HSI) with lower-resolution specific chlorophyll types and carotenoids measured by HPLC to examine Holocene trophic state changes and anoxia evolution in the meromictic Lake Jaczno, NE Poland. A redundancy analysis (RDA) including pollen-inferred vegetation cover, temperature and human impacts provides insight into specific conditions and drivers of changing trophic and redox states in the lake. Anoxic and sulfidic conditions were established in Lake Jaczno after initial basin infilling 9500 years ago. Until 6700 cal BP, lake trophy was relatively low, water turbidity was high and green sulfur bacteria (GSB) were abundant within the phototrophic community, suggesting a deep oxic–anoxic boundary and weak stratification. The period between 6700–500 cal BP is characterized by constantly increasing lake production and a gradual shift from GSB to purple sulfur bacteria (PSB), suggesting a shallower oxic–anoxic boundary and pronounced stratification. Yet, the presence of spheroidene and speroidenone in the sediments indicates intermittent anoxia. After 500 cal BP, increasing human impact, deforestation and intensive agriculture promoted lake eutrophication, with a shift to PSB dominance and establishment of permanent anoxia and meromixis. Our study unambiguously documents the legacy of human impact on processes determining eutrophication and anoxia.

Temperature feedback control of laser cladding using high resolution hyperspectral imaging

2016 ◽  
Author(s):  
Wim Devesse ◽  
Dieter De Baere ◽  
Michaël Hinderdael ◽  
Patrick Guillaume
Keyword(s):  
High Resolution ◽  
Feedback Control ◽  
Hyperspectral Imaging ◽  
Laser Cladding ◽  
Temperature Feedback

scholarly journals High-resolution grain size distribution of sediment core with hyperspectral imaging

2019 ◽  
Vol 393-394 ◽  
pp. 105536 ◽  
Author(s):  
Kévin Jacq ◽  
Charline Giguet-Covex ◽  
Pierre Sabatier ◽  
Yves Perrette ◽  
Bernard Fanget ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Size Distribution ◽  
Hyperspectral Imaging ◽  
Grain Size Distribution ◽  
Sediment Core

Hyperspectral drill-core imaging for ore characterization

2020 ◽  
Author(s):  
Laura Tusa ◽  
Mahdi Khodadadzadeh ◽  
Margret Fuchs ◽  
Richard Gloaguen ◽  
Jens Gutzmer
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
High Resolution ◽  
Hyperspectral Imaging ◽  
Mineral Exploration ◽  
Electromagnetic Spectrum ◽  
Drill Core ◽  
Ore Characterization ◽  
Ore Types ◽  
Drill Cores

<p>Mineral exploration campaigns represent an essential step in the discovery and evaluation of ore deposits required to fulfil the global demand for raw materials. Thousands of meters of drill-cores are extracted in order to characterize a specific exploration target. Hyperspectral imaging is recently being explored in the mining industry as a tool to complement traditional logging techniques and to provide a rapid and non-invasive analytical method for mineralogical characterization. The method relies on the fact that minerals have different spectral responses in specific portions of the electromagnetic spectrum. Sensors covering the visible to near-infrared (VNIR) and short-wave infrared (SWIR) are commonly used to identify and estimate the relative abundance of minerals such as phyllosilicates, amphiboles, carbonates, iron oxides and hydroxides as well as sulphates (Clark, 1999). The distribution of these mineral phases can frequently be used as a proxy for the distribution of ore minerals such as sulphides. Typical core imaging systems can acquire hyperspectral data from a whole drill-core tray in a matter of seconds. Available sensors record data in several hundreds of contiguous spectral bands at spatial resolutions around 1 mm/pixel.</p><p>​​In this work, we apply a local high-resolution mineralogical analysis, such as SEM-MLA (Kern et al., 2018), for a precise and exhaustive mineral mapping of some selected small samples. We then upscale these mineralogical data acquired from thin sections to drill-core scale by integrating hyperspectral imaging and machine learning techniques. Our proposed method is composed of two main steps. In the first step, after initially co-registering the hyperspectral and high-resolution mineralogical data and making a training set, a machine learning model is trained. In the second step, we apply the learned model to obtain mineral abundance and association maps over entire drill-cores.</p><p>​​The mapping is further used for the calculation of other mineralogical parameters essential to exploration and further mining stages such as modal mineralogy, mineral association, alteration indices, metal grade estimates and hardness. The proposed methodological framework is illustrated on samples collected from a porphyry type deposit, but the procedure is easily adaptable to other ore types. Therefore, this approach can be integrated in the standard core-logging routine, complementing the on-site geologists and can serve as background for the geometallurgical analysis of numerous ore types.  </p><p>​​</p><p>​​Clark, R. N., 1999, “Spectroscopy of rocks and minerals, and principles of spectroscopy,” in Remote sensing for the earth sciences: Manual of remote sensing, vol. 3, John Wiley & Sons, Inc, pp. 3–58.</p><p>​​Gandhi, S. M. and Sarkar, B. C., 2016, “Drilling,” in Essentials of Mineral Exploration and Evaluation, pp. 199–234.</p><p>​​Kern, M., Möckel, R., Krause, J., Teichmann, J., Gutzmer, J., 2018. Calculating the deportment of a fine-grained and compositionally complex Sn skarn with a modified approach for automated mineralogy. Miner. Eng. 116, 213–225.</p>

Rapid calibrated high-resolution hyperspectral imaging using tunable laser source

2009 ◽  
Author(s):  
Lam K. Nguyen ◽  
Eli Margalith
Keyword(s):  
High Resolution ◽  
Hyperspectral Imaging ◽  
Tunable Laser ◽  
Laser Source ◽  
Tunable Laser Source

Model-based Skin Pigment Cartography by High-Resolution Hyperspectral Imaging

2017 ◽  
Vol 2017 (8) ◽  
pp. 108-114
Author(s):  
Pierre Seroul ◽  
Mathieu Hébert ◽  
Marie Cherel ◽  
Romain Vernet ◽  
Raphael Clerc ◽  
...  
Keyword(s):  
High Resolution ◽  
Hyperspectral Imaging ◽  
Model Based ◽  
Skin Pigment
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