Determination of SiO2 Content in Boron-Containing Silica Refractories by Hydrofluoric Acid Gravimetry

2010 ◽  
Vol 177 ◽  
pp. 478-480
Author(s):  
Jian Ping Xu
Keyword(s):  
Conventional Method ◽  
Hydrofluoric Acid ◽  
Sio2 Content ◽  
Positive Interference

The co-volatilization of boron and silicon has been studied for determination of SiO2 content in boron-containing silica refractories. The co-volatilization of boron may cause positive interference for determining of SiO2 content. The interference can be eliminated by the volatilization of boron with 5mL and 2mL of ethanol by separately volatizing, before volatilization of SiO2 with hydrofluoric acid. The method for determination of SiO2 content in boron-containing silica refractories has been established. The scope and precision of this method are equaled to that of the conventional method by hydrofluoric acid gravimetry.

scholarly journals Determination of impurities in highly purified hydrofluoric acid by ICP-MS.

1993 ◽  
Vol 42 (7) ◽  
pp. T113-T117 ◽  
Author(s):  
Yutaka NAKAMURA ◽  
Sigeto SIGEMORI ◽  
Takako TAKAHASHI ◽  
Yuichi TAKAKU ◽  
Tadashi SIMAMURA
Keyword(s):  
Hydrofluoric Acid ◽  
Icp Ms ◽  
Determination Of Impurities

scholarly journals USE OF HYDROFLUORIC ACID IN THE DETERMINATION OF MANGANESE IN IRON AND ORES.

1898 ◽  
Vol 20 (7) ◽  
pp. 504-506 ◽  
Author(s):  
Allen P. Ford ◽  
I. M. Bregowsky
Keyword(s):  
Hydrofluoric Acid

Characterization and Manipulation of Exposed Ge Nanocrystals

2004 ◽  
Vol 818 ◽  
Author(s):  
I.D. Sharp ◽  
Q. Xu ◽  
C.Y. Liao ◽  
D.O. Yi ◽  
J.W. Ager ◽  
...  
Keyword(s):  
Hydrofluoric Acid ◽  
Metal Films ◽  
Silica Matrix ◽  
Size Distributions ◽  
Si Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Oxide Matrix ◽  
Ge Nanocrystals

AbstractIsotopically pure 70Ge and 74Ge nanocrystals embedded in SiO2 thin films on Si substrates have been fabricated through ion implantation and thermal annealing. Nanocrystals were subsequently exposed using a hydrofluoric acid etching procedure to selectively remove the oxide matrix while retaining up to 69% of the implanted Ge. Comparison of transmission electron micrographs (TEM) of as-grown crystals to atomic force microscope (AFM) data of exposed crystals reveals that the nanocrystal size distribution is very nearly preserved during etching. Therefore, this process provides a new means to use AFM for rapid and straightforward determination of size distributions of nanocrystals formed in a silica matrix. Once exposed, nanocrystals may be transferred to a variety of substrates, such as conducting metal films and optically transparent insulators for further characterization.

scholarly journals Simple and Exact Closed-Form Expression for Determination of a Penetrated Ray Path in a Ray Tracing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hyun Wook Moon ◽  
Woojoong Kim ◽  
Sewoong Kwon ◽  
Jaeheung Kim ◽  
Young Joong Yoon
Keyword(s):  
Closed Form ◽  
Approximate Method ◽  
Ray Tracing ◽  
Conventional Method ◽  
Closed Form Expression ◽  
Indoor Environments ◽  
Straight Line ◽  
Ray Path ◽  
Ray Tracing Simulation

A simple and exact closed-form equation to determine a penetrated ray path in a ray tracing is proposed for an accurate channel prediction in indoor environments. Whereas the penetrated ray path in a conventional ray tracing is treated as a straight line without refraction, the proposed method is able to consider refraction through the wall in the penetrated ray path. Hence, it improves the accuracy in ray tracing simulation. To verify the validation of the proposed method, the simulated results of conventional method, approximate method, and proposed method are compared with the measured results. The comparison shows that the proposed method is in better agreement with the measured results than the conventional method and approximate method, especially in high frequency bands.

scholarly journals Newly Developed System For The Analysis Of Micro Quantites Of Molybdenum (VI) Using Flow Injection Analysis

2007 ◽  
Vol 4 (2) ◽  
pp. 180-190
Author(s):  
Baghdad Science Journal
Keyword(s):  
Hydrogen Peroxide ◽  
Acid Medium ◽  
Conventional Method ◽  
Flow Injection ◽  
Flow Injection Analysis ◽  
Better Than

New microphotometer was constructed in our Laboratory Which deals with the determination of Molybdenum (VI) through its Catalysis effect on Hydrogen peroxide and potasum iodide Reaction in acid medium H2SO4 0.01 mM. Linearity of 97.3% for the range 5- 100 ppm. The repeatability of result was better than 0.8 % 0.5 ppm was obtanined as L.U. (The method applied for the determination of Molybdenum (VI) in medicinal Sample (centrum). The determination was compared well with the developed method the conventional method.

scholarly journals Microwave Digestion for Determination of Aluminum, Boron, and 13 Other Elements in Plants by Inductively Coupled Plasma Atomic Emission Spectrometry

1997 ◽  
Vol 80 (3) ◽  
pp. 647-650 ◽  
Author(s):  
Da-Hai Sun ◽  
James K Waters ◽  
Thomas P Mawhtnney
Keyword(s):  
Hydrofluoric Acid ◽  
Inductively Coupled Plasma ◽  
Microwave Digestion ◽  
Atomic Emission ◽  
Atomic Emission Spectrometry ◽  
Emission Spectrometry ◽  
Plasma Atomic Emission ◽  
Plasma Atomic Emission Spectrometry ◽  
Inductively Coupled

Abstract A microwave digestion procedure was developed for determining aluminum and boron and 13 other elements in plant tissues by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sample (0.5 g) was digested in a closed Teflon vessel with 10 mL concentrated nitric acid and 3 mL hydrofluoric acid, and further digested in an open Teflon vessel with 5 mL hydrogen peroxide. Excess hydrofluoric acid was eliminated by adding 0.2 g silicon (IV) oxide. Four National Institute of Standards and Technology standard reference materials (apple leaves, peach leaves, tomato leaves, and pine needles) were analyzed to test the reliability of the method. The excellent recoveries indicate that the proposed procedure is simple and effective for determination of Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P, S, Sr, and Zn in plants.

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