scholarly journals Molecular and atomic emission during single- bubble cavitation in concentrated sulfuric acid

2005 ◽  
Vol 6 (3) ◽  
pp. 157-161 ◽  
Author(s):  
David J. Flannigan ◽  
Kenneth S. Suslick
1979 ◽  
Vol 57 (19) ◽  
pp. 2546-2548 ◽  
Author(s):  
Rafik O. Loutfy ◽  
Cheng-Kuo Hsiao

An analytical procedure was developed to determine the content of metallic impurities in metal-free phthalocyanine (H2Pc) pigments. The technique involves dissolving the pigment in concentrated sulfuric acid, followed by oxidative degradation using hydrogen peroxide. Phthalimide was the only organic oxidation product. The remaining trace metals in the solution were determined using plasma atomic emission. The trace metals content in a commercial α polymorph of phthalocyanine pigment (ICI-Monolite Fast Blue GS) was monitored as a function of purification processes. Experiment showed that Monolite Fast Blue contains 2500 ppm Na; 350 ppm Ca, and 370 ppm Fe. Purification of this material by extraction with hot dimethyl-formamide gave β-H2Pc, which contained 300 ppm Na, 110 ppm Ca, and 310 ppm Fe. Sulfuric acid purification (acid pasting) reduced the content of non-transition elements, but in-increased the content of transition metals.These results were compared to the trace metal content in H2Pc pigment which were synthesized.


2018 ◽  
Author(s):  
Harold Jeffrey M. Consigo ◽  
Ricardo S. Calanog ◽  
Melissa O. Caseria

Abstract Gallium Arsenide (GaAs) integrated circuits have become popular these days with superior speed/power products that permit the development of systems that otherwise would have made it impossible or impractical to construct using silicon semiconductors. However, failure analysis remains to be very challenging as GaAs material is easily dissolved when it is reacted with fuming nitric acid used during standard decapsulation process. By utilizing enhanced chemical decapsulation technique with mixture of fuming nitric acid and concentrated sulfuric acid at a low temperature backed with statistical analysis, successful plastic package decapsulation happens to be reproducible mainly for die level failure analysis purposes. The paper aims to develop a chemical decapsulation process with optimum parameters needed to successfully decapsulate plastic molded GaAs integrated circuits for die level failure analysis.


2020 ◽  
Vol 3 (441) ◽  
pp. 104-109
Author(s):  
N.A. Bektenov ◽  
◽  
N.C. Murzakassymova ◽  
M.A. Gavrilenko ◽  
А.N. Nurlybayeva ◽  
...  

1985 ◽  
Vol 50 (8) ◽  
pp. 1714-1726 ◽  
Author(s):  
Václav Dědek ◽  
Igor Linhart ◽  
Milan Kováč

Sodium alkoxide-catalyzed addition of methanol, ethanol and propanol to 3-chlorononafluoro-1,5-hexadiene (I) proceeds at temperatures -35 °C to 8 °C with allyl rearrangement, affording 1,6-dialkoxy-1,1,2,3,4,4,5,6,6-octafluoro-2,4-hexadiene (V) as the principal product, along with 1,6-dialkoxy-1,2,3,3,4,5,6,6-octafluoro-1,5-diene (VI) and trans-1,6-dialkoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (VII). The ethers Va-Vc consist of the cis,trans- and trans,trans-isomers in about 3 : 1 ratio, whereas the ethers VIa-VIc have trans,trans-configuration. Ethers Vc and VIc react with concentrated sulfuric acid to give dipropyl 2,3,4,5-tetrafluoro-2,4-hexadienedioate (IX) and dipropyl 2,3,4,4,5-pentafluoro-2-hexenedioate (X), respectively, whereas the ether VIIc affords a mixture of propyl 6-propyloxy-2,3,4,4,5,6-heptafluoro-2-hexenoate (XI) and ester X. Addition of methanol to perfluoro-1,3,5-hexatriene (II) affords 1,1,2,3,4,5,6,6-octafluoro-1,6-dimethoxy-3-hexene (XIII) as the principal product.


Molbank ◽  
10.3390/m1190 ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. M1190
Author(s):  
Andreas S. Kalogirou ◽  
Panayiotis A. Koutentis

Reaction of 4,5,6-trichloropyrimidine-2-carbonitrile (1) with concentrated sulfuric acid at ca. 20 °C gave 4,5,6-trichloropyrimidine-2-carboxamide (5) in 91% yield. The new compound was fully characterized by IR, MALDI-TOF, NMR and elemental analysis.


1995 ◽  
Vol 5 (2) ◽  
pp. 65-66 ◽  
Author(s):  
Mikhail V. Gorelik ◽  
Vera I. Lomzakova ◽  
Elena A. Khamidova ◽  
Vitalii Ya. Shteiman ◽  
Marianna G. Kuznetsova ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 25 (49) ◽  
pp. no-no
Author(s):  
B.-M. IM ◽  
E. AKIYAMA ◽  
H. HABAZAKI ◽  
A. KAWASHIMA ◽  
K. ASAMI ◽  
...  

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