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Biogenic silica Wikipedia

Biogenic silica (bSi), also referred to as opal, biogenic opal, or amorphous opaline silica, forms one of the most widespread biogenic minerals. For example, microscopic particles of silica called phytoliths can be found in grasses and other plants. Silica is an amorphous metal oxide formed by complex inorganic polymerization processes. This is opposed to the other major biogenic minerals, comprising carbonate and phosphate, which occur in nature as crystalline iono-covalent solids (e.g. salts) whose precipitationis dic

Biogenic silica: a neglected component of the coupled

Jul 25, 2008 Siting Qiu, Shuijing Zhai, Hui Gao, Huishan Mi, Dynamics of biogenic silica accumulation and ecological characteristics in single-species communities and ecotones in Min River estuary, China, Chemosphere, 10.1016/j.chemosphere.2020.128645, (128645), (2020).

(PDF) Biogenic Silica researchgate.net

Biogenic silica (BSi), a chemically determined proxy, measures the amorphous Si content Limnological investigation of biogenic silica. sedimentation and silica biogeochemistry in Lake St

(PDF) Limnological investigation of biogenic silica

Limnological investigation of biogenic silica sedimentation and silica biogeochemistry in Lake St. Moritz and Lake Zürich Article (PDF Available) in Aquatic Sciences 49(1):42-50 · February 1987

biogenic silica investigation

Biogenic silica cycle in surface sediments of the. In contrast to several investigations of biogenic silica (BSi) content and recycling in surface sediments of the Southern Ocean, little is known about the benthic cycle of BSi in high northern latitudes.

Biogenic silica dissolution in seawater — in vitro

Jan 01, 2001 This investigation shows that the study of biogenic silica dissolution has accumulated a complex web of models and practical approaches. However, in cutting through this, two extreme situations can be identified; the dissolution of biogenic silica

Quantification of biogenic silica by means of Fourier

Jul 21, 2016 Biogenic silica and quartz share most of their prominent SiO absorption features in the synthetic spectrum. Differentiation between the two silicate phases is possible upon close inspection of the spectral range between 1080 and 1100 cm −1,where biogenic silica leads to a band shift and the formation of a broader shoulder towards higher

Biogenic Silica Analysis Standard Operating Procedure

silica comes from biogenic sources, i.e. diatoms, and non-biogenic sources, i.e. clays. Timed aliquots are extracted from the sodium hydroxide and dyed molybdate blue. Spectrophotometry is used to determine the samples absorption at 812 nm. The absorption percent is then used to calculate the percent biogenic silica in the sample. Safety

Biogenic silica. Refra

Biogenic silica is a natural, renewable raw material. Rice husks are used in modern biomass power plants as a quality-controlled source of energy. Hereby, the raw material is burned in a CO 2-neutral manner. This means that during combustion, no more CO 2 is released than the rice plant absorbed from the atmosphere during its growth. An aspect

Natural hybrid silica/protein superstructure at atomic

Dec 08, 2020 Silicatein is the first discovered enzymatically active multifunctional protein that catalyzes the polymerization of biogenic silica and is key to its subsequent condensation and shaping (13 ⇓ –15).Initially, three isoforms—silicatein-α, silicatein-β, and silicatein- γ, in a molar ratio of 12:6:1 and molecular masses of 29, 28, and 27 kDa, respectively—were observed in the axial

Biogenic Silica Patterning: Simple Chemistry or Subtle

Moise Ndao, Gil Goobes, Prashant S. Emani, Gary P. Drobny, A REDOR ssNMR Investigation of the Role of an N-Terminus Lysine in R5 Silica Recognition,

(PDF) Limnological investigation of biogenic silica

Limnological investigation of biogenic silica sedimentation and silica biogeochemistry in Lake St. Moritz and Lake Zürich Article (PDF Available) in Aquatic Sciences 49(1):42-50 · February 1987

Frontiers An Overlooked Silica Source of the Modern

Reactive surface area control of the dissolution kinetics of biogenic silica in deep-sea sediments. Chem. Geol. 132, 125–130. doi: 10.1016/S0009-2541(96)00047-2

Biogenic silica cycle in surface sediments of the

In contrast to several investigations of biogenic silica (BSi) content and recycling in surface sediments of the Southern Ocean, little is known about the benthic cycle of BSi in high northern latitudes. Therefore, we investigated the silicic acid concentration of pore water and BSi content of surface sediments from the Greenland Sea. Low BSi contents of less than 2% were observed.

Highly Hierarchical Fibrillar Biogenic Silica with

A new discovery of highly hierarchical fibrillar biogenic silica with mesoporous structure derived from the perennial plant Equisetum fluviatile was made. By removing the organic compounds through chemical and heat treatment, the biogenic silica skeleton can largely retained the original highly hierarchical structure of the plant stems. Infrared spectra, X-ray diffraction, and small-angle X

Impact of Biocompatible Nanosilica on Green Stabilization

Oct 22, 2019 Biogenic silica NPs synthesis. In a typical recipe, the contaminated raw wheat husks as silica precursor were washed with tap water and dried in the oven at

Silica in Plants: Biological, Biochemical and Chemical

Investigation into the modes by which Si polymerization proceeds in vivo and the effects of the surrounding environment has led to the development of several laboratory-based model systems to monitor the processes of silicification in vitro. Structural aspects of biogenic silica,

SIT Graduate Institute/SIT Study Abroad SIT Digital

In this investigation, biogenic silica (BSi), total organic carbon (TOC), δ 13 C values, and carbon: nitrogen ratios were analyzed between lakes through northern Iceland, to review possible complicating factors specific to the use of

HETA 88-119-2345 NIOSH INVESTIGATORS AUGUST 1993

sugarcane smoke among sugarcane workers. Since the smoke contains "biogenic silica" fibers (BSF), chronic respiratory diseases were of particular concern. During March 2-11, 1988, NIOSH investigators met with representatives of the Hawaii Department of Health, the Hawaiian Sugar Planters' Association, the Hawaiian Commercial and Sugar

Biogenic Silica Composition and Storage in the Yellow

Nov 11, 2019 The composition and accumulation of BSi and its role in C sequestration in the YRDW were quantified based on field investigation combined with remote sensing observation in the Yellow River Delta Wetland (YRDW). Results show that the soil BSi pool in the YRDW mainly consists of phytoliths. The pools of BSi, TOC, and BSi-occluded C (OCBSi) for aboveground plants in the YRDW

Biogenic silica dissolution in the oceans: Reconciling

1. Introduction [2] Diatoms (Bacillariophyceae), which contribute up to half of global primary production, form exoskeletons of amorphous silica or opal. Between 10 and 100% of the mass of biogenic silica produced redissolves within the euphotic zone [Nelson et al., 1995; Tréguer et al., 1995; Nelson and Brzezinski, 1997].The remaining diatomaceous opal rapidly settles to the seafloor [Billet

Highly Hierarchical Fibrillar Biogenic Silica with

Scanning electron microscopy and transmission electron microscopy investigation reveal that the biogenic silica are fibers with diameters of about 120-150 μm and lengths of more than a few centimeters. These fibers consist of smaller fasciculus with diameters of about 5-15 μm that are composed of three levels of particles with mass and

Biogenic silica dissolution in the oceans: Reconciling

1. Introduction [2] Diatoms (Bacillariophyceae), which contribute up to half of global primary production, form exoskeletons of amorphous silica or opal. Between 10 and 100% of the mass of biogenic silica produced redissolves within the euphotic zone [Nelson et al., 1995; Tréguer et al., 1995; Nelson and Brzezinski, 1997].The remaining diatomaceous opal rapidly settles to the seafloor [Billet

Highly Hierarchical Fibrillar Biogenic Silica with

A new discovery of highly hierarchical fibrillar biogenic silica with mesoporous structure derived from the perennial plant Equisetum fluviatile was made. By removing the organic compounds through chemical and heat treatment, the biogenic silica skeleton can largely retained the original highly hierarchical structure of the plant stems. Infrared spectra, X-ray diffraction, and small-angle X

Frontiers An Overlooked Silica Source of the Modern

Reactive surface area control of the dissolution kinetics of biogenic silica in deep-sea sediments. Chem. Geol. 132, 125–130. doi: 10.1016/S0009-2541(96)00047-2

Biogenic Silica Composition and Storage in the Yellow

Nov 11, 2019 The composition and accumulation of BSi and its role in C sequestration in the YRDW were quantified based on field investigation combined with remote sensing observation in the Yellow River Delta Wetland (YRDW). Results show that the soil BSi pool in the YRDW mainly consists of phytoliths. The pools of BSi, TOC, and BSi-occluded C (OCBSi) for aboveground plants in the YRDW

Comparative activity evaluation for silica raw materials

Silica raw materials are widely used in many industries, especially in the manufacture of building materials. Among all rocks with rockforming silica minerals, chemogenic and biogenic sedimentary rocks are highly demanded as active (pozzolanic) mineral additives for composite binders. Raw materials containing amorphous silica are used to obtain composites of the TiO2–SiO2 system with

SIT Graduate Institute/SIT Study Abroad SIT Digital

In this investigation, biogenic silica (BSi), total organic carbon (TOC), δ 13 C values, and carbon: nitrogen ratios were analyzed between lakes through northern Iceland, to review possible complicating factors specific to the use of

Justin P. Dodd NIU Geology and Environmental Geosciences

Aug 14, 2018 Diagenesis and Biogenic Silica. In order to understand the variations observed in biogenic silica from sedimentary records, it is necessary to quantify variables that can cause changes in the oxygen and silicon isotope values of biogenic silica during diagenesis (post-mortem alteration).

HETA 88-119-2345 NIOSH INVESTIGATORS AUGUST 1993

sugarcane smoke among sugarcane workers. Since the smoke contains "biogenic silica" fibers (BSF), chronic respiratory diseases were of particular concern. During March 2-11, 1988, NIOSH investigators met with representatives of the Hawaii Department of Health, the Hawaiian Sugar Planters' Association, the Hawaiian Commercial and Sugar

Biogenic substance Wikipedia

A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, it has developed to encompass any constituents, secretions, and metabolites of plants or animals. In context of molecular biology, biogenic substances are referred to as biomolecules.They are generally isolated and measured

Early diagenetic alterations of biogenic and reactive

Sedimentary biogenic silica (BSi) is an important parameter for understanding biogeochemical processes in estuarine ecosystems. In this study, a two-step mild acid-mild alkaline extraction procedure was used to leach BSi and its early diagenetic products from the sediments of the Yangtze Estuary. A Si/Al correction of the mild alkaline leachable silica (Si-Alk) was applied to estimate the

ETERMINATION IOGENIC OPAL IN PELAGIC ARINE SEDIMENTS S

amount of biogenic silica present, with the KOH treatment producing values two to three times greater than the Na 2CO 3 leach. The com-monly used 2-M Na 2CO 3 leach is inadequate for the rapid digestion of biogenic opal for radiolarians (e.g., Leg 199 sediments), but a 2-M KOH solution will produce reasonably accurate results.

44. THE INFLUENCE OF BIOGENIC SILICA ON SEISMIC

These biogenic silica-rich sediments have a significantly lower satu­ The first regional investigation of Tertiary and Mesozoic sediment distribution in the Norwegian-Greenland Sea was carried out by Eldholm and Windisch (1974). Sellevoll (1975) mapped the sediment distribution east of the

THE CHEMISTRY OF SILICA GBV

Silica Precipitated from Colloidal Silica Sols 564 Silica Precipitated from Vapor: Pyrogenic Silica 565 Vaporized Si02, Oxidation of SiO vapor, Oxidation and hydrolysis of SiCl4 vapor, Oxidation and hydrolysis of silicon esters vapors, Hydrolysis of SiF4 vapor Naturally Occurring Silica Powders 568 Microcrystalline Hydrated Silicas 569