scholarly journals Rapid column experiments to study replacement of exchangeable cations in soil samples.

1989 ◽  
Vol 37 (3) ◽  
pp. 213-225
Author(s):  
S. El-Guindy ◽  
J. Harmsen
Keyword(s):  
High Performance ◽  
Soil Column ◽  
Breakthrough Curves ◽  
Soil Samples ◽  
Exchangeable Cations ◽  
High Flow ◽  
Model Calculations ◽  
Small Column ◽  
Exchange Processes ◽  
Leaching Solution

A new and rapid soil column technique is described that can verify model calculations on transport and exchange of cations in soil, using equipment for high-performance liquid chromatography (HPLC). Breakthrough curves of cations are presented and compared with results of a model that simulates transport and exchange processes in a soil column. The small column dimensions and the high flow rate allow leaching of individual columns to be completed within one day. Equiulibrium is established almost instantaneously between the leaching solution and the soil in the column. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Geophysically-based analysis of BTCs and ion exchange processes in soil

2020 ◽  
Author(s):  
Shany Ben Moshe ◽  
Pauline Kessouri ◽  
Dana Erlich ◽  
Alex Furman
Keyword(s):  
Ion Exchange ◽  
Soil Column ◽  
Breakthrough Curves ◽  
Soil Profiles ◽  
The Real ◽  
Water Composition ◽  
Exchange Processes ◽  
Heterogeneous Soil ◽  
Quantitative Examination ◽  
Transport Patterns

Abstract. Breakthrough curves (BTCs) are a valuable tool for qualitative and quantitative examination of transport patterns in porous media. Although breakthrough (BT) experiments are simple, they often require extensive sampling and multi-component chemical analysis. In this work, we examine spectral induced polarization (SIP) signals measured along a soil column during a BT experiment in a homogeneous and heterogeneous soil profiles. Soil profiles were equilibrated with an NaCl background solution and then a constant flow of CaCl2 solution was applied. SIP signature was recorded, and complementary ion analysis was performed on the collected outflow samples. Our results confirm that changes to the pore-water composition, ion exchange processes and profile heterogeneity are detectable by SIP: the real part of the conductivity-based BTCs clearly indicated the BT of the non-reactive ions as well as the retarded BT of Ca2+. The imaginary part of the conductivity-based curves reacted to the changes in ion mobility around the electrical double layer (EDL) and indicated the initiation and the termination of the Na+–Ca2+ exchange reaction. Finally, both the real and imaginary components of the complex conductivity reacted to the presence of a coarser textured layer in the heterogeneous profile.

scholarly journals Geophysically based analysis of breakthrough curves and ion exchange processes in soil

2021 ◽  
Vol 25 (6) ◽  
pp. 3041-3052
Author(s):  
Shany Ben Moshe ◽  
Pauline Kessouri ◽  
Dana Erlich ◽  
Alex Furman
Keyword(s):  
Ion Exchange ◽  
Soil Column ◽  
Breakthrough Curves ◽  
Soil Profiles ◽  
The Real ◽  
Water Composition ◽  
Exchange Processes ◽  
Heterogeneous Soil ◽  
Quantitative Examination ◽  
Transport Patterns

Abstract. Breakthrough curves (BTCs) are a valuable tool for qualitative and quantitative examination of transport patterns in porous media. Although breakthrough (BT) experiments are simple, they often require extensive sampling and multi-component chemical analysis. In this work, we examine spectral induced polarization (SIP) signals measured along a soil column during BT experiments in homogeneous and heterogeneous soil profiles. Soil profiles were equilibrated with an NaCl background solution, and then a constant flow of either CaCl2 or ZnCl2 solution was applied. The SIP signature was recorded, and complementary ion analysis was performed on the collected outflow samples. Our results confirm that changes to the pore-water composition, ion exchange processes and profile heterogeneity are detectable by SIP: the real part of the SIP-based BTCs clearly indicated the BT of the non-reactive ions as well as the retarded BT of cations. The imaginary part of the SIP-based curves changed in response to the alteration of ion mobility around the electrical double layer (EDL) and indicated the initiation and the termination of the cation exchange reaction. Finally, both the real and imaginary components of the complex conductivity changed in response to the presence of a coarser textured layer in the heterogeneous profile.

scholarly journals Performance of EasyBreath Decathlon Snorkeling mask for delivering continuous positive airway pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alberto Noto ◽  
Claudia Crimi ◽  
Andrea Cortegiani ◽  
Massimiliano Giardina ◽  
Filippo Benedetto ◽  
...  
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
High Performance ◽  
Positive Airway Pressure ◽  
High Flow ◽  
Hospital Capacity ◽  
System Generator ◽  
Flow Generator ◽  
Full Face ◽  
Support Devices

AbstractDuring the COVID-19 pandemic, the need for noninvasive respiratory support devices has dramatically increased, sometimes exceeding hospital capacity. The full-face Decathlon snorkeling mask, EasyBreath (EB mask), has been adapted to deliver continuous positive airway pressure (CPAP) as an emergency respiratory interface. We aimed to assess the performance of this modified EB mask and to test its use during different gas mixture supplies. CPAP set at 5, 10, and 15 cmH2O was delivered to 10 healthy volunteers with a high-flow system generator set at 40, 80, and 120 L min−1 and with a turbine-driven ventilator during both spontaneous and loaded (resistor) breathing. Inspiratory CO2 partial pressure (PiCO2), pressure inside the mask, breathing pattern and electrical activity of the diaphragm (EAdi) were measured at all combinations of CPAP/flows delivered, with and without the resistor. Using the high-flow generator set at 40 L min−1, the PiCO2 significantly increased and the system was unable to maintain the target CPAP of 10 and 15 cmH2O and a stable pressure within the respiratory cycle; conversely, the turbine-driven ventilator did. EAdi significantly increased with flow rates of 40 and 80 L min−1 but not at 120 L min−1 and with the turbine-driven ventilator. EB mask can be safely used to deliver CPAP only under strict constraints, using either a high-flow generator at a flow rate greater than 80 L min−1, or a high-performance turbine-driven ventilator.

Statistical Description of Isotope Exchange Processes: A Multisite Model for the 18O Exchange

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1161-1169 ◽  
Author(s):  
Paul Rösch
Keyword(s):  
Active Site ◽  
Isotope Exchange ◽  
Analytical Procedure ◽  
Matrix Formalism ◽  
Model Calculations ◽  
Exchange Processes ◽  
Reaction Solution ◽  
Different Types ◽  
Refinement Procedure

Abstract An analytical procedure has been developed for the determination of isotope exchange processes as exemplified by the 18O exchange catalysed by enzyme-nucleotide complexes. The model is able to handle more than one type of active site per reaction solution and is also able to distinguish between different types of inequivalence of the oxygens of enzyme bound Pi. Use of transition matrix formalism and basic statistical considerations lead directly to the simple model. A data refinement procedure is introduced and model calculations are shown.

scholarly journals Leaching of Picloram in ultisol under different rainfall volumes

2011 ◽  
Vol 29 (spe) ◽  
pp. 1129-1136 ◽  
Author(s):  
E.C Assis ◽  
A.A Silva ◽  
L D'Antonino ◽  
M.E.L.R Queiroz ◽  
L.C Barbosa
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Soil Samples ◽  
Soil Sampling ◽  
Horizontal Position ◽  
Leaching Potential ◽  
Excess Water ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Plot Design

The present study aimed to evaluate the leaching potential of Picloram in Ultisol columns under different rainfall amounts. For such, 30 treatments were evaluated (one soil associated with three levels of rainfall and ten depths).The experiments were arranged in a split-plot design, in a completely randomized design, with four replications. PVC columns of 10 cm in diameter and 50 cm in length were filled with these soils, moistened, and placed upright for 48 hours to drain the excess water. The herbicide was applied and rainfall simulations were carried out at specified intensities, according to the treatments, to force Picloram leaching. After 72 hours, all the columns were arranged in a horizontal position and opened lengthwise. Then, soil sampling was carried out every 5 cm of depth for subsequent herbicide extraction and quantification and analysis by high performance liquid chromatography. The remaining soil samples were placed in plastic pots, and, at the respective depths, the indicator species Cucumis sativus was sown. Twenty-one days after the emergence (DAE) of the indicator plants, evaluations were conducted to verify the symptoms of toxicity caused by Picloram in the plants. It was concluded that Picloram leaching is directly dependent on the volume of rain applied. The herbicide reached the deepest regions in the soil with the highest intensity of rain. The results obtained by bioassay were in agreement with those found by liquid chromatography.

scholarly journals Fungal diversity in high Andean ecuadorian forest soil

2021 ◽  
Author(s):  
Adrian Valdez ◽  
Sergio Covarrubias
Keyword(s):  
Fungal Diversity ◽  
High Performance ◽  
Its Region ◽  
Taxonomic Composition ◽  
Soil Samples ◽  
Fungal Communities ◽  
Gallery Forest ◽  
Volcanic Soils ◽  
Altitudinal Gradients ◽  
The Andes

The Andes range in Ecuador presents high biodiversity and characteristic altitudinal gradients, which are frequently threatened by deforestation and farming. In particular, forest have developed in the high inter-Andean alley on volcanic soils forming a unique ecoregion. Little is known on the fungal biodiversity of soil in such high Andean gallery forest submitted to strong degradation pressures. Therefore, in this study we evaluated wether the soil mycobiome was associated with altitudinal gradients during the dry season. Three representative locations were selected based on altitude: A (3,309 meters above the sea level, masl), B (3,809 masl) and C (4,409 masl). High performance sequencing (NGS) of the ITS region of ribosomal DNA genes with Illumina technology was used to explore the fungal taxonomic composition in the soil samples. Our results showed changes in the structure of fungal communities in the different locations, related to the relative abundance of Amplicon Sequence Variants (ASV). Higher fungal diversity was related with the altitudinal gradient with average taxa ranging from 675, 626 and 556 ASVs, respectively from location A to C. The results highlight the complexity and diversity of fungal communities in high Andean forest and the need to protect these unique mycobiomes. The findings in this ecosystem of Ecuador will improve our understanding of distribution, diversity, ecology, and biological perspectives for the restoration of terrestrial microbiomes.

Construction of heterostructured NiFe2O4-C nanorods by transition metal recycling from simulated electroplating sludge leaching solution for high performance lithium ion batteries

Nanoscale ◽  
2020 ◽  
Vol 12 (25) ◽  
pp. 13398-13406
Author(s):  
Xueqian Lei ◽  
Youpeng Li ◽  
Changzhou Weng ◽  
Yanzhen Liu ◽  
Weizhen Liu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
High Performance ◽  
Lithium Ion ◽  
Metal Recycling ◽  
Electroplating Sludge ◽  
Leaching Solution

This work provides a potential direction for high performance lithium ion battery anodes by recycling metals from electroplating sludge.

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