Insight into the mechanism of accumulation of arsenate and phosphate in hydro lake sediments by measuring the rate of dissolution with ethylenediaminetetraacetic acid

1986 ◽  
Vol 20 (2) ◽  
pp. 183-186 ◽  
Author(s):  
John. Aggett ◽  
Lynley Susan. Roberts
Keyword(s):  
Lake Sediments ◽  
Ethylenediaminetetraacetic Acid ◽  
Rate Of Dissolution ◽  
Insight Into

New Insight into Ethylenediaminetetraacetic Acid Tetrasodium Salt as a Sacrificing Sodium Ion Source for Sodium-Deficient Cathode Materials for Full Cells

2019 ◽  
Vol 11 (6) ◽  
pp. 5957-5965 ◽  
Author(s):  
Jae Hyeon Jo ◽  
Ji Ung Choi ◽  
Yun Ji Park ◽  
Jiefang Zhu ◽  
Hitoshi Yashiro ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Ethylenediaminetetraacetic Acid ◽  
Ion Source ◽  
Sodium Ion ◽  
Insight Into

The dualistic approach of FCA: A further insight into Ontario Lake sediments

Chemosphere ◽  
2008 ◽  
Vol 70 (11) ◽  
pp. 2025-2031 ◽  
Author(s):  
Paola Annoni ◽  
Rainer Brüggemann
Keyword(s):  
Lake Sediments ◽  
Insight Into ◽  
Dualistic Approach

scholarly journals Vertical distribution of Fe and Fe(III)-reducing bacteria in the sediments of Lake Donghu, China

2015 ◽  
Vol 61 (8) ◽  
pp. 575-583 ◽  
Author(s):  
Cuicui Tian ◽  
Chunbo Wang ◽  
Yingying Tian ◽  
Xingqiang Wu ◽  
Bangding Xiao
Keyword(s):  
Vertical Distribution ◽  
Lake Sediments ◽  
Solid Phase ◽  
Inorganic Phosphorus ◽  
Nitrogen And Phosphorus ◽  
Inorganic Substances ◽  
Reducing Bacteria ◽  
The Vertical Distribution ◽  
Insight Into ◽  
Phosphorus Levels

In lake sediments, iron (Fe) is the most versatile element, and the redox cycling of Fe has a wide influence on the biogeochemical cycling of organic and inorganic substances. The aim of the present study was to analyze the vertical distribution of Fe and Fe(III)-reducing bacteria (FeRB) in the surface sediment (30 cm) of Lake Donghu, China. At the 3 sites we surveyed, FeRB and Fe(II)-oxidizing bacteria (FeOB) coexisted in anoxic sediments. Geobacter-related FeRB accounted for 5%–31% of the total Bacteria, while Gallionella-related FeOB accounted for only 0.1%–1.3%. A significant correlation between the relative abundance of poorly crystalline Fe and Geobacter spp. suggested that poorly crystalline Fe favored microbial Fe(III) reduction. Poorly crystalline Fe and Geobacter spp. were significantly associated with solid-phase Fe(II) and total inorganic phosphorus levels. Pore water Fe(II) concentrations negatively correlated with NO3–at all sites. We concluded that Geobacter spp. were abundant in the sediments of Lake Donghu, and the redox of Fe might participate in the cycling of nitrogen and phosphorus in sediments. These observations provided insight into the roles of microbial Fe cycling in lake sediments.

scholarly journals Exploring chemo-mechanics of granular material using DEM

2021 ◽  
Vol 249 ◽  
pp. 14013
Author(s):  
P. Viswanath ◽  
Arghya Das
Keyword(s):  
Granular Media ◽  
Mechanical Response ◽  
Earth Pressure ◽  
Mechanical Degradation ◽  
Sensitive Material ◽  
Lateral Earth Pressure ◽  
Rate Of Dissolution ◽  
Custom Made ◽  
Dem Analysis ◽  
Insight Into

Particle Size Distribution (PSD) is one of the prime guiding factors of granular media response. Degradation via weathering is a process, which brings about a gradual shift in the PSD. In nature, chemically sensitive material like calcite undergoes chemo-mechanical degradation bringing about variations in their behaviour. In the present study, an experimental investigation is carried out to get insight into the mechanical response during the coupled chemo-mechanical process. The experiments were carried out at two different rates of dissolutions in a custom made 1D compression mould. From the experiments, it is clear that the higher rate of dissolution reduces the lateral earth pressure more than the lower rate. Discrete Element Method (DEM) analyses the micromechanical process behind the observed response from experiments. The results showed a reduction in lateral stress as soon as the dissolution starts. DEM analysis confirms the competing mechanism between grain size reduction and grain rearrangement as the guiding element for the granular media response.

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

Stochasting modeling of planetary ring systems

1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart
Keyword(s):  
Maximum Entropy ◽  
Ring System ◽  
The Sun ◽  
Ultimate State ◽  
Interparticle Interactions ◽  
Ring Systems ◽  
First Order ◽  
Planetary Ring ◽  
Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

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