Exploration of a Two-Step Aqueous Process for the Valorization of Sodium Fluorosilicate (Na2SiF6), an Intermediate Product of the Fluorosilicic Acid Conversion

Author(s):  
Samba Ndiaye ◽  
Alpha O. Toure ◽  
Falilou M. Sambe ◽  
Codou G. M. Diop ◽  
Laurent Prat ◽  
...  
1961 ◽  
Vol 6 (02) ◽  
pp. 224-234 ◽  
Author(s):  
E. T Yin ◽  
F Duckert

Summary1. The role of two clot promoting fractions isolated from either plasma or serum is studied in a purified system for the generation of intermediate product I in which the serum is replaced by factor X and the investigated fractions.2. Optimal generation of intermediate product I is possible in the purified system utilizing fractions devoid of factor IX one-stage activity. Prothrombin and thrombin are not necessary in this system.3. The fraction containing factor IX or its precursor, no measurable activity by the one-stage assay method, controls the yield of intermediate product I. No similar fraction can be isolated from haemophilia B plasma or serum.4. The Hageman factor — PTA fraction shortens the lag phase of intermediate product I formation and has no influence on the yield. This fraction can also be prepared from haemophilia B plasma or serum.


1970 ◽  
Vol 48 (21) ◽  
pp. 3291-3299 ◽  
Author(s):  
K. G. McCurdy ◽  
B. P. Erno

An investigation has been made of the kinetics of hydration of tricalcium silicate at several temperatures in a large excess of water in the presence of various added ions. The rate data have been interpreted by a reaction mechanism which involves: (a) the first order hydration of tricalcium silicate to form an intermediate product, 1.5CaO•SiO2, which can react by two pathways, (b) the direct first order decomposition of intermediate, 1.5CaO•SiO2, to form lime and silica or (b′) complexing of intermediate with silica and subsequent decomposition to form lime and silica. This reaction mechanism predicts the rate of production of base during the hydration. The effect of various added ions is interpreted in terms of the proposed mechanism.Rate constants and activation energies for the various steps in the proposed mechanism are reported.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4746
Author(s):  
An-Ting Tu ◽  
Jer-An Lin ◽  
Chieh-Hsiu Lee ◽  
Yi-An Chen ◽  
Jung-Tsung Wu ◽  
...  

5-Hydroxymethylfurfural (5-HMF) is a harmful substance generated during the processing of black garlic. Our previous research demonstrated that impregnation of black garlic with epigallocatechin gallate (EGCG) could reduce the formation of 5-HMF. However, there is still a lack of relevant research on the mechanism and structural identification of EGCG inhibiting the production of 5-HMF. In this study, an intermediate product of 5-HMF, 3-deoxyglucosone (3-DG), was found to be decreased in black garlic during the aging process, and impregnation with EGCG for 24 h further reduced the formation of 3-DG by approximately 60% in black garlic compared with that in the untreated control. The aging-mimicking reaction system of 3-DG + EGCG was employed to determine whether the reduction of 3-DG was the underlying mechanism of decreased 5-HMF formation in EGCG-treated black garlic. The results showed that EGCG accelerated the decrease of 3-DG and further attenuated 5-HMF formation, which may be caused by an additional reaction with 3-DG, as evidenced by LC-MS/MS analysis. In conclusion, this study provides new insights regarding the role of EGCG in blocking 5-HMF formation.


Author(s):  
Ke Zhang ◽  
Xingwei Wang

With the development of trade liberalization, the pollutants emissions embodied in global trade are increasing. The pollution haven hypothesis caused by trade has aroused wide attention. The fragmentation of international production has reshaped trade patterns. The proportion of intermediate product trade in global trade is increasing. However, little has been done to study the pollution haven of different pollutants under different trade patterns. In this paper, major environmental pollutants CO2 (carbon dioxide), SO2 (sulfur dioxide), and NOx (nitrogen oxides) are selected as the research objects. This study investigated the global pollution haven phenomenon in 43 countries and 56 major industries from 2000 to 2014. Based on the MRIO model, the trade mode is divided into three specific patterns: final product trade, intermediate product trade in the last stage of production, and the trade related to the global value chain. The results show that trade liberalization could reduce global CO2, SO2, and NOx emissions, and intermediate product trade has a more significant emission reduction effect than final product trade. Trade’s impacts on each country are various, and the main drivers are also different. For example, the European Union avoids becoming a pollution haven mainly through the trade related to the global value chain. The suppressed emissions under this trade pattern are 71.8 Mt CO2, 2.2 Mt SO2, 2.2 Mt NOx. India avoids most pollutants emissions through intermediate product trade. China has become the most serious pollution haven through final product trade. The trade pattern could increase China 829.4 Mt CO2, 4.5 Mt SO2, 2.6 Mt NOx emissions in 2014.


Author(s):  
Wirya Sarwana ◽  
Akihiko Anzai ◽  
Daichi Takami ◽  
Akira Yamamoto ◽  
Hisao Yoshida

Photocatalytic steam reforming of methane (PSRM) has been studied as an attractive method to produce hydrogen by utilizing photoenergy like solar energy around room temperature with metal-loaded photocatalysts, where methane...


1976 ◽  
Vol 29 (10) ◽  
pp. 2149 ◽  
Author(s):  
RJ Atkinson

FeC2O4,2H2O(s) suspensions in sodium hydroxide solutions were oxidized by a fast air-bubble flow at room temperature until complete reaction had occurred. With amounts of NaOH in the range OH/Fe initial mole ratio ≤1.0, the reaction is FeC2O4, 2H2(s)+ OH-(aq)+ �O2(g) → ⅔γFeOOH(s)+1/3Fe(C2O4)33-(aq)+13/6H2O With OH/Fe mole ratio ≥ 2.0 the reaction is FeC2O4, 2H2(s)+ 2OH-(aq)+ �O2(g) → αFeOOH(s)+(C2O4)33-(aq)+ 5/2 H2O Mixtures of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) form at intermediate OH/Fe mole ratio. The oxidation process occurs in a solid-phase intermediate product. Comparisons with similar oxidations of iron(11)sulphate solutions showed that γ-FeOOH formation was favoured and α-FeOOH formation inhibited in the iron(11) oxalate oxidation. These differences are related to pH and dissolved iron concentrations.


2018 ◽  
Vol 52 (4) ◽  
pp. 607-611 ◽  
Author(s):  
G. P. Panasyuk ◽  
L. A. Azarova ◽  
V. I. Privalov ◽  
V. N. Belan ◽  
I. G. Voroshilov ◽  
...  

2013 ◽  
Vol 46 (6) ◽  
pp. 1741-1748 ◽  
Author(s):  
Yi Xiong ◽  
Shuangfeng Jia ◽  
Jianbo Wang ◽  
Shang Peng ◽  
Lu Lu ◽  
...  

A powder of oxyfluorotitanate Na3TiOF5crystals is acquired as an intermediate product during the synthesis of anatase titanium dioxide (TiO2) nanosheets with a large percentage of exposed reactive {001} facets. By application of transmission electron microscopy techniques, mainly energy dispersive spectroscopy and selected-area electron diffraction, coherent domain variants of Na3TiOF5are shown to possess monoclinic structure with space groupP21/n. The occurrence of these orientation domain variants is attributed to the reduction of crystal symmetry as a result of the phase transition from the high-temperature cubic phase to the low-temperature monoclinic phase. Through a detailed group theory analysis, the orientation domains are shown to exhibit 12 variants and 11 domain boundaries, which can be categorized into three types of perpendicular twins and two types of antiparallel twins. This work may provide meaningful insight for understanding the growth mechanism of anatase TiO2with a high percentage of reactive facets.


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