Hydrolysis of friedel-crafts reaction products at different temperatures

2007 ◽  
Vol 30 (1) ◽  
pp. 642-647
Author(s):  
D. Ian Barnes ◽  
J. Gordon Robinson ◽  
George Marr
2019 ◽  
Vol 37 (No. 4) ◽  
pp. 246-251 ◽  
Author(s):  
Joanna Tkaczewska ◽  
Maciej Wielgosz ◽  
Piotr Kulawik ◽  
Marzena Zajac

The influence of drying temperature on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using NaOH and ethanol pre-treatment method, extracted in water in 45°C and then dried in 4 different temperatures: 50, 70, 80°C and freeze-dried. The  electrophoresis and functional properties of gelatines were investigated. Freeze drying allowed to obtain a high gelling force, and all other methods did not give satisfactory results. The proteins in gelatines dried at higher temperatures separated by electrophoresis gave severely blurred bands. It may be explained by thermal hydrolysis of collagen fibrils. Freeze drying is the only effective method for drying this product, which can be used in industry.


2002 ◽  
Vol 7 (3) ◽  
pp. 215-222 ◽  
Author(s):  
Wei Huang ◽  
Yan Zhang ◽  
J. Richard Sportsman

Cyclic nucleotide phosphodiesterases (PDEs) catalyze the hydrolysis of the 3′-ester bond of cyclic AMP (cAMP) and cyclic GMP (cGMP), important second messengers in the transduction of a variety of extracellular signals. There is growing interest in the study of PDEs as drug targets for novel therapeutics. We describe the development of a homogeneous fluorescence polarization assay for PDEs based on the strong binding of PDE reaction products (i.e., AMP or GMP) onto modified nanoparticles through interactions with immobilized trivalent metal cations. This assay technology (IMAP) is applicable to both cAMP- and cGMP-specific PDEs. Results of the assay in 384- and 1536-well microplates are presented.


2012 ◽  
Vol 58 (4) ◽  
pp. 10-22 ◽  
Author(s):  
Martin Reli ◽  
Kamila Kočí ◽  
Vlastimil Matějka ◽  
Pavel Kovář ◽  
Lucie Obalová

Abstract The kaolinite/TiO2 composite (60 wt% of TiO2) was prepared by thermal hydrolysis of a raw kaolin suspension in titanyl sulphate and calcined at different temperatures (600, 650 and 700°C) and for different times (1, 2 and 3 h). The obtained samples were characterized by XRPD, N2 physical adsorption and SEM, and tested for photocatalytic reduction of CO2. The different calcination conditions did not influence TiO2 phase composition, only slightly changed the specific surface area, and significantly affected crystallite size of kaolinite/TiO2 composite. A higher temperature and longer duration of calcination lead to higher crystallinity of the powder. The photocatalytic results showed that the crystallite size determined the efficiency of kaolinite/TiO2 photocatalysts.


2013 ◽  
Vol 67 (2) ◽  
pp. 293-298 ◽  
Author(s):  
C. Keating ◽  
D. Cysneiros ◽  
T. Mahony ◽  
V. O'Flaherty

In this study, the ability of various sludges to digest a diverse range of cellulose and cellulose-derived substrates was assessed at different temperatures to elucidate the factors affecting hydrolysis. For this purpose, the biogas production was monitored and the specific biogas activity (SBA) of the sludges was employed to compare the performance of three anaerobic sludges on the degradation of a variety of complex cellulose sources, across a range of temperatures. The sludge with the highest performance on complex substrates was derived from a full-scale bioreactor treating sewage at 37 °C. Hydrolysis was the rate-limiting step during the degradation of complex substrates. No activity was recorded for the synthetic cellulose compound carboxymethylcellulose (CMC) using any of the sludges tested. Increased temperature led to an increase in hydrolysis rates and thus SBA values. The non-granular nature of the mesophilic sludge played a positive role in the hydrolysis of solid substrates, while the granular sludges proved more effective on the degradation of soluble compounds.


2007 ◽  
Vol 361-363 ◽  
pp. 787-790
Author(s):  
Sabina Beranič Klopčič ◽  
Irena Pribošič ◽  
Tomaž Kosmač ◽  
Ute Ploska ◽  
Georg Berger

The reactivity of CaTi4(PO4)6 (CTP) with alumina and yttria-stabilized zirconia (Y-TZP) ceramics was studied. CTP powder was synthesized and composites with commercial alumina or zirconia matrices containing 10 wt% of CTP were prepared. They were sintered at different temperatures and characterized using XRD, SEM, and EDX analyses. The results showed that the alumina/CTP and Y-TZP/CTP composites start to react below 1000 °C. In the alumina/CTP composite the first reaction product, detected at 970 °C, was AlPO4. At temperatures above 1280 °C TiO2 and CaTiO3 were also formed and no CTP peaks could be detected using XRD analysis. The composite sintered at 1500 °C consisted of Al2O3 matrix, AlPO4, TiO2, CaTiO3 and Al2TiO5. The reaction products formed in the Y-TZP/CTP composite at 970 °C were TiO2 and Ca2Zr7O16. At higher sintering temperatures, 1280 °C and above, CTP was no longer present, Ca2Zr7O16 decomposed, forming CaO2 and ZrO2, and Y2O3 was consumed to form YPO4. Consequently, upon cooling to room temperature the matrix phase transformed to monoclinic ZrO2. Based on these results it can be concluded that CTP is not a suitable bioactive second phase for the fabrication of CTP composites with alumina or zirconia matrices.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Huseyin Sahin ◽  
Sevgi Kolayli ◽  
Mehmet Beykaya

Invertase and glucose oxidase are secreted by the hypopharyngeal glands of honeybees for the hydrolysis of sucrose and the preservation from microbial effects, respectively. It is also prominent to understand how the levels of invertase and glucose oxidase of raw honey samples are being influenced by different conditions because the behavior of these specific enzymes in raw honeys could be a marker for the quality parameters. On the basis of this expectation, three raw honey samples tagged as blossom, pine, and oak were investigated. To reach the desired aim, extraction conditions were diversified by the range of different periods as 0, 1, 3, and 6 h and of different temperatures as 24, 45, and 65°C. The optimal heating condition and the period of extraction for invertase activity of all honey types were 24°C and 1 h because data of this condition were 147.960–178.266 enzyme unit per kilogram (U/kg) and 20.179–24.313 invertase number (IN). Although the variety of glucose oxidase activity was not evaluated as a worthwhile indicator of quality for raw honey due to its abnormal activity behavior, the change of invertase activity should be considered as a quality parameter due to showing the gradual decreasing level from initially a quite high one.


1984 ◽  
Vol 39 (12) ◽  
pp. 1706-1710 ◽  
Author(s):  
H.-J. Wörz ◽  
E. Quien ◽  
H. P. Latscha

o-Phenylene-bis(dibromophosphane) (1) is prepared by reaction of P ,P,P′,P′-tetrakis(dim ethylamino)-o-phenylenediphosphane with hydrogen bromide in ether. The reaction of o-phenylene- bis(dichlorophosphane) (2) with CH3OH in ether yields o-phenylene-bis(phosphonousacid- dimethylester) (3). The Michaelis-Arbuzov conversion of 3, either by heat or by catalytic amounts of CH3I in toluene, yields ophenylene-bis(methylphosphinic-acid-methylester) (4). The reduction of 2 must be carried out with a large excess of LiAlH4 (1:4) in ether to give o-phenylenediphosphane (5). The cyclic anhydride (6) of P.P′-dichloro-o-phenylenediphosphonous acid is formed when 2 is hydrolyzed in ether with an equimolar amount of water. Complete hydrolysis of 2 with an excess of water gives o-phenylenediphosphonous acid (7). With hydrogen peroxide o-phenylenediphosphonic acid (8) can be isolated.


1995 ◽  
Vol 398 ◽  
Author(s):  
C. Barrera-Solano ◽  
M. PiÑero ◽  
C. Jiménez-Solís ◽  
L. Gago-Duport

ABSTRACTYSZ samples containing 5 and 10 mol% of Y203 were prepared by controlled hydrolysis of metal alkoxides. The dried powders were calcined at 800°C and then they were uniaxially pressed and sintered at different temperatures and next heated at 1400°C (∼ 5 MPa) or annealed at 1600°C for 24 h. The quantitative analysis of the experimental X-ray diffraction (XRD) spectra was performed by Whole Pattern Fitting (WPF). A Pseudo-Voigt (Thompson-Cox-Hastings) was used as shape profile function. The respective phase fractions (wt %) were fitted for both solid state solutions using the scale factor. The heat treatment induced changes are discussed.


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