Congruent melting of Ca-carbonate in static experiment at 3500 K and 10-22 GPa

2011 ◽  
Vol 3 (Special Issue) ◽  
pp. 1-7
Author(s):  
A. V. Spivak ◽  
L. S. Dubrovinsky ◽  
Yu. A. Litvin
Keyword(s):  
Congruent Melting ◽  
Static Experiment ◽  
Ca Carbonate

The Effect of Exogenous Fluoride on the Calcium PUMP, Ciliary Activity, and Shell Formation of the Fingernail Clam, Musculium Transversum

1982 ◽  
Vol 40 ◽  
pp. 58-59
Author(s):  
Anthony Paparo ◽  
Judy A. Murphy ◽  
Robert Dean
Keyword(s):  
Mississippi River ◽  
Calcium Pump ◽  
Bottom Fauna ◽  
Ciliary Activity ◽  
Shell Formation ◽  
Middle Reach ◽  
Shell Matrix ◽  
Fingernail Clams ◽  
Ca Carbonate

In the mid-1950's, fingernail clams virtually disappeared from a 100-mile section of the IL River, a tributary of the Mississippi River, due to unknown causes. A survey of the bottom fauna of the IL River in 1979, revealed that the clams were still absent from the middle reach of the River, where they had been abundant prior to the die-off in the 1950's. Some factor(s) in the River currently prevent the clams from recolonizing areas where they were formerly abundant. Recently, clams exposed to fluoride developed abnormal grooves in the shell matrix. Fluorides are known to be protoplasmic poisons removing essential body calcium by precipitation. Since the shell consists primarily of Ca carbonate, this investigation examines the possible role of fluoride on shell formation and the poisoning of the Ca pump which can directly inhibit lateral ciliary activity on the gill.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Design of Equipments for Nonlinear Static Experiment of Rubber Damping Materials

2016 ◽  
Vol 693 ◽  
pp. 64-68
Author(s):  
Cong Ling Zhu ◽  
C.H. Zhu ◽  
C.C. Li
Keyword(s):  
Constitutive Model ◽  
Design Optimization ◽  
Theoretical Basis ◽  
Experiment Design ◽  
Accurate Design ◽  
Nonlinear Static ◽  
Static Experiment ◽  
Damping Materials ◽  
Rubber Damper ◽  
Design And Application

In this paper, the static constitutive model of rubber damping materials, the equipment needed in experiment and the method of experiment design optimization are studied, providing new experiment design and theoretical basis for accurate design and application of vehicle rubber damper.

Mineral assemblage within secondary crystallized melt inclusions in olivine of mantle xenoliths from the Bultfontein kimberlite pipe (Kaapvaal craton, South Africa)

2021 ◽  
Author(s):  
Alexey Tarasov ◽  
Igor Sharygin ◽  
Alexander Golovin ◽  
Anna Dymshits ◽  
Dmitriy Rezvukhin
Keyword(s):  
Melt Inclusions ◽  
Basic Research ◽  
Kimberlite Pipe ◽  
Mantle Xenoliths ◽  
Mantle Minerals ◽  
Source Regions ◽  
Basic Research Grant ◽  
Carbonate Composition ◽  
First Time ◽  
Ca Carbonate

<p>For the first time, snapshots of crystallized melts in olivine of sheared garnet peridotite xenoliths from the Bultfontein kimberlite pipe have been studied. This type of xenoliths represents the deepest mantle rocks derived from the base of lithosphere (at depths from 110 to 230 km for various ancient cratons). According to different models, such type of inclusions (secondary) in mantle minerals can be interpreted as relics of the most primitive (i.e., close-to-primary) kimberlite melt that infiltrated into sheared garnet peridotites. In general, these secondary inclusions are directly related to kimberlite magmatism that finally formed the Bultfontein diamond deposits. The primary/primitive composition of kimberlite melt is poorly constrained because kimberlites are ubiquitously contaminated by xenogenic material and altered by syn/post-emplacement hydrothermal processes. Thus, the study of these inclusions helps to significantly advance in solving numerous problems related to the kimberlite petrogenesis.</p><p>The unexposed melt inclusions were studied by using a confocal Raman spectroscopy. In total, fifteen daughter minerals within the inclusions were identified by this method. Several more phases give distinct Raman spectra, but their determination is difficult due to the lack of similar spectra in the databases. Various carbonates and carbonates with additional anions, alkali sulphates, phosphates and silicates were determined among daughter minerals in the melt inclusions: calcite CaCO<sub>3</sub>, magnesite MgCO<sub>3</sub>, dolomite CaMg(CO<sub>3</sub>)<sub>2</sub>, eitelite Na<sub>2</sub>Mg(CO<sub>3</sub>)<sub>2</sub>, nyerereite (Na,K)<sub>2</sub>Ca(CO<sub>3</sub>)<sub>2</sub>, gregoryite (Na,K,Ca)<sub>2</sub>CO<sub>3</sub>, K-Na-Ca-carbonate (K,Na)<sub>2</sub>Ca(CO<sub>3</sub>)<sub>2</sub>, northupite Na<sub>3</sub>Mg(CO<sub>3</sub>)<sub>2</sub>Cl, bradleyite Na<sub>3</sub>Mg(PO<sub>4</sub>)(CO<sub>3</sub>), burkeite Na<sub>6</sub>(CO<sub>3</sub>)(SO<sub>4</sub>)<sub>2</sub>, glauberite Na<sub>2</sub>Ca(SO<sub>4</sub>)<sub>2</sub>, thenardite Na<sub>2</sub>SO<sub>4</sub>, aphthitalite K<sub>3</sub>Na(SO<sub>4</sub>)<sub>2</sub>, apatite Ca<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>(OH,Cl,F) and tetraferriphlogopite KMg<sub>3</sub>FeSi<sub>3</sub>O<sub>10</sub>(F,Cl,OH). Note that carbonates are predominant among the daughter minerals in the melt inclusions. Moreover, there are quite a lot of alkali-rich daughter minerals within the inclusions as well. During the last decade, some research groups using different approaches proposed a model of carbonate/alkali‑carbonate composition of kimberlite melts in their source regions. This model contradicts to the generally accepted ultramafic silicate nature of parental kimberlite liquids. This study is a direct support of a new model of carbonatitic composition of kimberlite melts and also shows that alkali contents in kimberlite petrogenesis are usually underestimated.</p><p>This work was supported by the Russian Foundation for Basic Research (grant No. 20-35-70058).</p>

scholarly journals Static Experiment and Finite Element Analysis of a Multitower Cable-Stayed Bridge with a New Stiffening System

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowei Wang ◽  
Yingmin Li ◽  
Weiju Song ◽  
Jun Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Force ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Practical Engineering ◽  
Static Experiment ◽  
Stiffening Effect ◽  
Better Than ◽  
Cable Stayed Bridges

Based on the stiffness limitations of the midtower in multitower cable-stayed bridges, a new stiffening system (tie-down cables) is proposed in this paper. The sag effects and wind-induced responses can be reduced with the proposed system because tie-down cables are short and aesthetic compared with traditional stiffening cables. The results show that the stiffening effect of tie-down cables is better than that of traditional stiffening cables in controlling the displacement and internal force of the bridge based on a static experiment and finite element analysis. Therefore, the proposed system can greatly improve the overall stiffness of a bridge, and its stiffening effect is better than that of traditional stiffening cables in controlling the displacement and internal force. The results provide a reference for the application of such systems in practical engineering.

scholarly journals Amorphous Polyphosphate and Ca‐Carbonate Nanoparticles Improve the Self‐Healing Properties of both Technical and Medical Cements

2020 ◽  
Vol 15 (12) ◽  
pp. 2000101 ◽  
Author(s):  
Emad Tolba ◽  
Xiaohong Wang ◽  
Shunfeng Wang ◽  
Meik Neufurth ◽  
Maximilian Ackermann ◽  
...  
Keyword(s):  
The Self ◽  
Self Healing ◽  
Ca Carbonate

Two rare-earth-based quaternary chalcogenides EuCdGeQ4 (Q = S, Se) with strong second-harmonic generation

2019 ◽  
Vol 48 (47) ◽  
pp. 17620-17625 ◽  
Author(s):  
Wenhao Xing ◽  
Naizheng Wang ◽  
Yangwu Guo ◽  
Zhuang Li ◽  
Jian Tang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Melting Behavior ◽  
Band Gaps ◽  
Metal Chalcogenides ◽  
Congruent Melting ◽  
Nlo Materials

Two RE-based quaternary metal chalcogenides EuCdGeQ4 (Q = S, Se) are discovered. They possess many attractive properties as preferred IR NLO materials including large band gaps, phase-matched intense SHG and congruent melting behavior.

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