قائمة الطعام
Needle-fibre calcite refers to needles and fibres of low-magnesium calcite, which are a few micrometres wide and up to several hundred micrometres long. In older micromorphological literature, especially from Eastern Europe and Russia, it has often been designated as lublinite (e.g., Ulrich, 1938, Kowalinski et al., 1972, Bal, 1975a, Bal ...
WhatsApp: +86 18221755073
The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer mantle epithelium...
WhatsApp: +86 18221755073
Needle-fiber calcite, also described as acicular calcite, is a common feature in carbonate soils, calcretes and caves. Many forms, shapes and arrangements of needle-fiber …
WhatsApp: +86 18221755073
adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86ANNX16AC86A
WhatsApp: +86 18221755073
needle-fiber calcite habits cited in the literature belong to this category. The third category includes needles 30.-1000 ~m long and 2-20 um wide. 652 ERIC P. VERRECCHIA AND KARIN E. VEBRECCHIA
WhatsApp: +86 18221755073
Fu S. Y., and Lauke B., Characterization of tensile behavior of hybrid short-glass fibre/calcite-particle/ABS composites. Composites, Part A: 1998, 29, 575–583. Crossref. Google Scholar. 3. Fu S. Y., and Lauke B., Analysis of mechanical properties of ABS terpolymer reinforced with short glass fibres and calcite particles.
WhatsApp: +86 18221755073
The biogenic origin of needle fibre calcite. G Cailleau, EP Verrecchia, O Braissant, L Emmanuel. Sedimentology 56 (6), 1858-1875, 2009. 138: 2009: Translation of energy into morphology: simulation of stromatolite morphospace using a stochastic model. C …
WhatsApp: +86 18221755073
On the origin of fiber calcite crystals in moonmilk deposits. JC Cañaveras, S Cuezva, S Sanchez-Moral, J Lario, L Laiz, JM Gonzalez, ... Naturwissenschaften 93, 27-32, 2006. 185: 2006: The biogeochemical role of Actinobacteria in Altamira Cave, Spain. S Cuezva, A Fernandez-Cortes, E Porca, L Pašić, V Jurado, ...
WhatsApp: +86 18221755073
Needle fibre calcite is one of the most ubiquitous habits of calcite in vadose environments (caves deposits, soil pores, etc.). Its origin, either through inorganic, indirect or direct biological … Expand
WhatsApp: +86 18221755073
Microbially induced calcite precipitation (MICP)–fiber combined reinforcement through the addition of fibers during the MICP process is a novel, natural, and green technique for foundation improvement, which can effectively enhance the mechanical properties of cemented soil. However, the small-strain dynamic properties of this method remain ...
WhatsApp: +86 18221755073
The article deals with the carbonates, filling fissures in limestone bedrock and presently exposed in a south-facing rock wall of Kramnica hill (Pieniny Klippen Belt, southern Poland). The carbonates are composed of (i) needle-fibre calcite crystals, (ii) carbonate nanofibres, (iii) carbonate nanoparticles, and (iv) micrite and sparite calcite crystals. Detrital grains from the …
WhatsApp: +86 18221755073
In Volume 56 of Sedimentology, Cailleau et al. (2009) presented a thorough investigation of needle fibre calcites (NFC) in low to mid-latitude vadose environments. Based on the observed micromorphologies and dO and dC composition of NFC from 11 sites, they concluded that the NFC have a purely biogenic origin (''In conclusion, the biogenic origin of NSF, in its original …
WhatsApp: +86 18221755073
Calcite moonmilk, which is a cave deposit formed of calcite crystals and water, is found in many caves in the Italian Alps. These modern and ancient deposits are formed of fiber calcite crystals, 50-500 nm wide and 1 to Ͼ 10 m long, and polycrystalline chains that have few crystal defects.
WhatsApp: +86 18221755073
Reliability of stable carbon and oxygen isotope compositions of pedogenic needle fibre calcite as environmental indicators: examples from Western Europe
WhatsApp: +86 18221755073
1. Introduction. Needle-fiber calcite, also described as acicular calcite, is a common feature in carbonate soils, calcretes and caves. Many forms, shapes and arrangements of needle-fiber calcite have been identified and two processes are responsible for their formation: physicochemical precipitation; and biomineralization (Phillips and Self, 1987, Verrecchia and …
WhatsApp: +86 18221755073
Pedogenic needle-fiber calcite was studied regarding its morphology, texture and stable isotope composition from the paleosol of the Quaternary Várhegy travertine (Budapest, Hungary). The needle-fiber calcite is composed of 40–200 μm long
WhatsApp: +86 18221755073
Needle fibre calcite (NFC) is formed by fungal activity in soils. NFC morphotypes show different Ca and Sr isotope signatures. The primary simple needles form at low …
WhatsApp: +86 18221755073
This needle-fiber calcite is monocrystalline and prismatic, and is associated with the physical weathering of Mytilus edulis (Linnaeus) bivalve shells found in soils from anthropic shell middens located on the northern coast of the Beagle Channel (Argentina). The effects of freeze-thaw cycles can be observed in the local soils and would be ...
WhatsApp: +86 18221755073
Needle-fiber calcite represents one of the peculiar forms of pedogenic carbonates in soils, paleosols and calcretes. Its formation is thought to be related to organic or inorganic processes mostly independent from each other: needles-fibers may be products of fungal biomineralization or physicochemical precipitation from soil solution (Verrecchia and …
WhatsApp: +86 18221755073
The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer …
WhatsApp: +86 18221755073
It is composed of thin calcite needles named NFC (needle fiber calcites) presenting various morphologies, calcite nanofibers and water, all in varying proportions (Hill, 1976; Verrecchia ...
WhatsApp: +86 18221755073
A comparison of similar ultrastructural characteristics of fungal hyphae and NFC has been performed to highlight analogies between both features and demonstrate the probable close relationship between fungal filaments and NFC and its associated nanofibers. Needle fiber calcite (NFC) is an ubiquitous terrestrial secondary calcium carbonate mineral often associated with …
WhatsApp: +86 18221755073
Carbon and oxygen isotope compositions of the needle fibre calcite (NFC) from two soils observed in quarries (Villiers and Savagnier) in the Swiss Jura Mountains are used to investigate the ...
WhatsApp: +86 18221755073
The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer mantle epithelium (OME) secrete calcite material and generate the characteristic fibre morphology and composite microstructure of the shell.
WhatsApp: +86 18221755073
The fibre width is controlled by the structure of the vein surface, which is composed of a thin rim of quartz crystals in case of the antitaxial calcite veins from Oppaminda Creek, and other examples from across the world.
WhatsApp: +86 18221755073
In several calcrete profiles from South Australia, needle-fibre calcite is concentrated in the channels and voids of nodules, hardpans, carbonate silt and platy calcrete. The morphology, spatial arrangements and crystallography of the needle-fibre calcite were determined using scanning and transmission electron microscopy. Needle-fibre calcite is composed of single …
WhatsApp: +86 18221755073
Stable carbon and oxygen isotope analyses were conducted on pedogenic needle fibre calcite (NFC) from seven sites in areas with roughly similar temperate climates in Western Europe, including the Swiss Jura Mountains, eastern and southern …
WhatsApp: +86 18221755073
Pedogenic needle-fiber calcite was studied regarding its morphology, texture and stable isotope composition from the paleosol of the Quaternary Várhegy travertine (Budapest, …
WhatsApp: +86 18221755073
Needle fibre calcite (NFC) is a habitus of calcium carbonate (CaCO 3 ) frequently observed in environments affected by pedogenic processes (Durand et al., 2018) as well as in caves as a component ...
WhatsApp: +86 18221755073
Needle fibre calcite is one of the most ubiquitous habits of calcite in vadose environments (caves deposits, soil pores, etc.). Its origin, either through inorganic, indirect or …
WhatsApp: +86 18221755073
The fibre width is controlled by the structure of the vein surface, which is composed of a thin rim of quartz crystals in case of the antitaxial calcite veins from Oppaminda Creek, and other examples from across the world.
WhatsApp: +86 18221755073
Needle fibre calcite is one of the most ubiquitous habits of calcite in vadose environments (caves deposits, soil pores, etc.). Its origin, either through inorganic, indirect or direct biological pro...
WhatsApp: +86 18221755073
6-8 wt.% plantain fibre (PF) and 34 wt.% calcite particles-(CP). Specifically, the composite containing 6 wt.% PF and 3 wt.% CP achieved the highest ultimate tensile strength of 63.77 MPa, optimal elongation at break, and the best thermal insulating property of 0.24 W/m·K. In contrast, the composite with 8 wt.% PF and 4 wt.% CP exhibited the
WhatsApp: +86 18221755073
The optimum fibre content for carbon and basalt fibre was 0.40%, whereas, for polypropylene, it stood at 0.20%. The maximum UCS, STS, UPV and average CaCO 3 were observed in a basalt fibre-reinforced biotreated …
WhatsApp: +86 18221755073
Needle fibre calcite (NFC) is one of the most common forms of secondary calcium carbonate in soil environments. It is a calcite monocrystal in the shape of a needle with a length 4 to 10 4 times its width (Verrecchia and Verrecchia, 1994). NFC is present over a large range of latitudes and altitudes (Cailleau et al., 2009a).
WhatsApp: +86 18221755073
The optimum fibre content for carbon and basalt fibre was 0.40%, whereas, for polypropylene, it stood at 0.20%. The maximum UCS, STS, UPV and average CaCO 3 were observed in a basalt fibre-reinforced biotreated sample with a fibre content of 0.40%, subjected to 18-day biotreatment. Conversely, the sample without fibre-reinforcement, biotreated ...
WhatsApp: +86 18221755073حقوق النشر ©2000- 2024 شركة شنغهاي زينيث
