Combining spectroscopic and flux measurement techniques to determine solid-phase speciation and solubility of phosphorus in agricultural soils

Geoderma ◽  
2022 ◽  
Vol 410 ◽  
pp. 115677
Author(s):  
Jirapat Tuntrachanida ◽  
Worachart Wisawapipat ◽  
Surachet Aramrak ◽  
Natthapol Chittamart ◽  
Wantana Klysubun ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Solid Phase ◽  
Measurement Techniques ◽  
Flux Measurement

scholarly journals On the use of plume models to estimate the flux in volcanic gas plumes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Julia Woitischek ◽  
Nicola Mingotti ◽  
Marie Edmonds ◽  
Andrew W. Woods
Keyword(s):  
Electrochemical Sensors ◽  
Measurement Techniques ◽  
Flux Measurement ◽  
Hydrothermal Systems ◽  
Mount Etna ◽  
Volcanic Gas ◽  
Gas Flux ◽  
Convective Structures ◽  
Video Images ◽  
Villarrica Volcano

AbstractMany of the standard volcanic gas flux measurement approaches involve absorption spectroscopy in combination with wind speed measurements. Here, we present a new method using video images of volcanic plumes to measure the speed of convective structures combined with classical plume theory to estimate volcanic fluxes. We apply the method to a nearly vertical gas plume at Villarrica Volcano, Chile, and a wind-blown gas plume at Mount Etna, Italy. Our estimates of the gas fluxes are consistent in magnitude with previous reported fluxes obtained by spectroscopy and electrochemical sensors for these volcanoes. Compared to conventional gas flux measurement techniques focusing on SO2, our new model also has the potential to be used for sulfur-poor plumes in hydrothermal systems because it estimates the H2O flux.

Modelling uranium leaching from agricultural soils to groundwater as a criterion for comparison with complementary safety indicators

2006 ◽  
Vol 932 ◽  
Author(s):  
D. Jacques ◽  
J. Šimůnek ◽  
D. Mallants ◽  
M.Th. van Genuchten
Keyword(s):  
Soil Profile ◽  
Reactive Transport ◽  
Transport Model ◽  
Agricultural Soils ◽  
Solid Phase ◽  
Water Flux ◽  
Fertilizer Application ◽  
Mineral Fertilizers ◽  
Deep Soil ◽  
Long Time

ABSTRACTNaturally occurring radionuclides can also end up in soils and groundwater due to human practices, such as application of certain fertilizers in agriculture. Many mineral fertilizers, particularly (super)phosphates, contain small amounts of 238U and 230Th which eventually may be leached from agricultural soils to underlying water resources. Field soils that receive P-fertilizers accumulate U and Th and their daughter nuclides, which eventually may leach to groundwater. Our objective was to numerically assess U migration in soils. Calculations were based on a new reactive transport model, HP1, which accounts for interactions between U and organic matter, phosphate, and carbonate. Solid phase interactions were simulated using a surface complexation module. Furthermore, all geochemical processes were coupled with a model accounting for dynamic changes in the soil water content and the water flux. The capabilities of the code in calculating natural U fluxes to groundwater were illustrated using a semi-synthetic 200-year long time series of climatological data for Belgium. Based on an average fertilizer application, the input of phosphate and uranium in the soil was defined. This paper discusses calculated U distributions in the soil profile as well as calculated U fluxes leached from a 100-cm deep soil profile. The calculated long-term leaching rates originating from fertilization are significantly higher after 200 years than estimated release rates from lowlevel nuclear waste repositories.

scholarly journals Comparison of heat flux measurement techniques during the DIII-D metal ring campaign

2017 ◽  
Vol T170 ◽  
pp. 014007 ◽  
Author(s):  
J L Barton ◽  
R E Nygren ◽  
E A Unterberg ◽  
J G Watkins ◽  
M A Makowski ◽  
...  
Keyword(s):  
Heat Flux ◽  
Measurement Techniques ◽  
Flux Measurement ◽  
Metal Ring ◽  
Heat Flux Measurement

Base heat flux measurement techniques in impulse hypersonic test facilities

2019 ◽  
Vol 48 (6) ◽  
pp. 2414-2427
Author(s):  
Kiran J. Irimpan ◽  
Viren Menezes ◽  
K. Srinivasan
Keyword(s):  
Heat Flux ◽  
Measurement Techniques ◽  
Flux Measurement ◽  
Heat Flux Measurement

Fe(II)-catalyzed transformation of Fe (hydr)oxides in particle-size soil organic matter fractions from amended agricultural soils

2020 ◽  
Author(s):  
Beatrice Giannetta ◽  
Ramona Balint ◽  
Daniel Said-Pullicino ◽  
César Plaza ◽  
Maria Martin ◽  
...  
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Agricultural Soils ◽  
Solid Phase ◽  
Organic Amendments ◽  
Fine Sand ◽  
Organic C ◽  
Amended Soils ◽  
Mineral Transformations

<p>Redox-driven changes in Fe crystallinity and speciation may affect soil organic matter (SOM) stabilization and carbon (C) turnover, with consequent influence on global terrestrial soil organic carbon (SOC) cycling.<span> </span>Under reducing conditions, increasing concentrations of Fe(II) released in solution from the reductive dissolution of Fe (hydr)oxides may accelerate ferrihydrite transformation, although our understanding of the influence of SOM on these transformations is still lacking.<span> </span></p><p>Here, we evaluated abiotic Fe(II)-catalyzed mineralogical changes in Fe (hydr)oxides in bulk soils and size-fractionated SOM pools (for comparison, fine silt plus clay, FSi+Cl, and fine sand, FSa) of an agricultural soil, unamended or amended with biochar, municipal solid waste compost, and a combination of both.<span> </span></p><p>FSa fractions showed the most significant Fe(II)-catalyzed ferrihydrite transformations with the consequent production of well-ordered Fe oxides irrespective of soil amendment, with the only exception being the compost-amended soils. In contrast, poorly crystalline ferrihydrite still constituted <em>ca. </em>45% of the FSi+Cl fractions of amended soils, confirming the that the higher SOM content in this fraction inhibits atom exchange between aqueous Fe(II) and the solid phase. Building on our knowledge of Fe(II)-catalyzed mineralogical changes in simple systems, our results evidenced that the mechanisms of abiotic Fe mineral transformations in bulk soils depend on Fe mineralogy, organic C content and quality, and organo-mineral associations that exist across particle-size SOM pools. Our results underline that in the fine fractions the increase in SOM due to organic amendments can contribute to limiting abiotic Fe(II)-catalyzed ferrihydrite transformation, while coarser particle-size fractions represent an understudied pool of SOM subjected to Fe mineral transformations.<span> </span></p>

scholarly journals A miniaturized method for fast, simple, and sensitive pesticide analysis in soils

2021 ◽  
Author(s):  
Marcel Pierre Simon ◽  
Dennis Knuth ◽  
Leonard Böhm ◽  
Katrin Wiltschka ◽  
Marlene Schatz ◽  
...  
Keyword(s):  
World War Ii ◽  
Solid Phase Microextraction ◽  
Agricultural Soils ◽  
Solid Phase ◽  
Sample Volume ◽  
World War ◽  
Quechers Method ◽  
Solid Liquid ◽  
Good Agreement ◽  
Different Soils

Abstract Purpose Organochlorine pesticides (OCPs) like lindane and DDT have been used extensively after World War II until the 1990s. Still, residues of these pesticides can be found in agricultural soils all over the world, especially in developing countries. Often, they occur in extensive areas and elevated concentrations so that food safety is jeopardized. Hence, simple, cheap, and fast analytical methods are needed for a straight-forward assessment of risks. A miniaturized solid–liquid extraction combined with solid-phase microextraction (SPME) based on a proven ISO method is presented. Methods The performance of the method is evaluated by extracting three different soils which were spiked with HCH and DDT congeners, and trifluralin, and aged for 35 days. The results are compared with those of a modified quick, easy, cheap, efficient, rugged, and safe (QuEChERS) method. For further validation, both methods are applied to three environmental soil samples. Results Validation results show limits of detection and quantification as well as recovery rates in good agreement with standard requirements. The new method was found to be quicker than QuEChERS, which requires time-consuming preparation of reagents. Conclusion Merits include low time and sample volume requirements (0.5 g) and the possibility to extract many samples simultaneously, which allows the screening of large sample sizes to determine the pollution status of whole landscape regions. However, access to an automated SPME apparatus is assumed. The authors can recommend this method as a cheap and fast alternative where SPME is available.

scholarly journals Quantifying fugitive gas emissions from an oil sands tailings pond with open-path Fourier transform infrared measurements

2021 ◽  
Vol 14 (2) ◽  
pp. 945-959
Author(s):  
Yuan You ◽  
Samar G. Moussa ◽  
Lucas Zhang ◽  
Long Fu ◽  
James Beck ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Oil Sands ◽  
Measurement Techniques ◽  
Flux Measurement ◽  
Fourier Transform Infrared ◽  
Inverse Dispersion ◽  
Nh3 Emission ◽  
Open Path ◽  
Infrared Measurements ◽  
Emission Fluxes

Abstract. Fugitive emissions from tailings ponds contribute significantly to facility emissions in the Alberta oil sands, but details on chemical emission profiles and the temporal and spatial variability of emissions to the atmosphere are sparse, since flux measurement techniques applied for compliance monitoring have their limitations. In this study, open-path Fourier transform infrared spectroscopy was evaluated as a potential alternative method for quantifying spatially representative fluxes for various pollutants (methane, ammonia, and alkanes) from a particular pond, using vertical-flux-gradient and inverse-dispersion methods. Gradient fluxes of methane averaged 4.3 g m−2 d−1 but were 44 % lower than nearby eddy covariance measurements, while inverse-dispersion fluxes agreed to within 30 %. With the gradient fluxes method, significant NH3 emission fluxes were observed (0.05 g m−2 d−1, 42 t yr−1), and total alkane fluxes were estimated to be 1.05 g m−2 d−1 (881 t yr−1), representing 9.6 % of the facility emissions.

A measurement technique for direct axis and quadrature axis magnetic characteristics in a projected pole (stationary field type) synchronous machine

2011 ◽  
Vol 34 (4) ◽  
pp. 401-410
Author(s):  
SI Manjur Basha ◽  
R Joseph Xavier ◽  
A Ebenezer Jeyakumar
Keyword(s):  
Direct Method ◽  
Measurement Techniques ◽  
Flux Measurement ◽  
Open Circuit ◽  
Synchronous Machine ◽  
Experimental Investigations ◽  
Magnetic Characteristics ◽  
Stationary Field ◽  
Field Type ◽  
Novel Approach

The magnetic characteristics of a projected pole stationary field type synchronous machine are important in design and performance studies though they differ along direct axis (d-axis) and quadrature axis (q-axis). It is difficult to determine the q-axis magnetic characteristics, whereas the determination of d-axis magnetic characteristics can be done by performing an open-circuit characteristics test on the machine. In order to estimate both the d–q axes magnetic characteristics by a direct method, various flux measurement techniques such as the moving coil flux meter, ballistic galvanometer, magneto resistance flux meter, Hall effect flux meter and solid-state diode-flux meter have been analysed. A novel approach of using germanium diodes as flux sensors is proposed in this work to determine experimentally the d–q axes magnetic characteristics. The implementation of hardware, experimental investigations and the results are presented here. Furthermore, the merits and applications of the proposed method are also discussed.

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