Influence of isopropyl alcohol concentration in urea solution on cloud point and solid point of dewaxed product

1987 ◽  
Vol 23 (2) ◽  
pp. 77-78
Author(s):  
E. Sh. Abdullaev ◽  
A. G. Ismailov ◽  
A. Sh. Gadzhiev ◽  
R. D. Balayan
Author(s):  
Nguyet Dau Tran Anh ◽  
Hieu Van Vo Kim ◽  
Thanh Van Tran Thi ◽  
Luan Huynh Nguyen Thanh ◽  
◽  
...  

The pyramid-structured silicon substrate was successfully fabricated by a chemical corrosion method with an average thickness of about 1 - 3 μm with the optimal parameters such as corrosion temperature of 70oC, corrosion time of 5 min, concentration KOH of 3 M and isopropyl alcohol concentration of 1 M. After that, the silver nanoparticles layer (thickness 20 nm) was coated on the silicon substrate by a sputtering method to enhance the SERS signal. The results proved that the Pyramid/nano Ag structure silicon substrate showed the enhancement effect of Raman signal, and Rhodamine 6G pigment in food at low concentration (10-6 M) was detected and the enhancement factor was 9.7 × 102.


1973 ◽  
Vol 26 (10) ◽  
pp. 2089 ◽  
Author(s):  
BJ Brown ◽  
NT Barker ◽  
DF Sangster

The solvated electron has been investigated in mixtures of polar and non-polar liquids (methanol, ethanol, propanol, and isopropyl alcohol respectively in hexane) by pulse-radiolysis. The respective yields and transition energies of the electron in the mixtures do not show the same dielectric dependence as has been established for pure liquids. The relative number of electrons escaping geminate recombination increases with an increase in the alcohol concentration but the mechanisms of optical transition and electron decay remain unchanged. Infrared spectroscopic studies have shown that electron stabilization is related to the existence of quasi-stable associated alcohol complexes. For ethanol, an observed decrease in the solvated free electron yield with an increase in temperature is in accord with a shift in associative equilibrium.


Author(s):  
J.M. Guilemany ◽  
F. Peregrin

The shape memory effect (SME) shown by Cu-Al-Mn alloys stems from the thermoelastic martensitic transformation occuring between a β (L2,) metastable phase and a martensitic phase. The TEM study of both phases in single and polycrystalline Cu-Al-Mn alloys give us greater knowledge of the structure, order and defects.The alloys were obtained by vacuum melting of Cu, Al and Mn and single crystals were obtained from polycrystalline alloys using a modified Bridgman method. Four different alloys were used with (e/a) ranging from 1.41 to 1.46 . Two different heat treatments were used and the alloys also underwent thermal cycling throughout their characteristic temperature range -Ms, Mf, As, Af-. The specimens were cut using a low speed diamond saw and discs were mechanically thinned to 100 μm and then ion milled to perforation at 4 kV. Some thin foils were also prepared by twin-jet electropolishing, using a (1:10:50:50) urea: isopropyl alcohol: orthophosphoric acid: ethanol solution at 20°C. The foils were examinated on a TEM operated at 200 kV.


2020 ◽  
pp. 66-72
Author(s):  
Irina A. Piterskikh ◽  
Svetlana V. Vikhrova ◽  
Nina G. Kovaleva ◽  
Tatyana O. Barynskaya

Certified reference materials (CRM) composed of propyl (11383-2019) and isopropyl (11384-2019) alcohols solutions were created for validation of measurement procedures and control of measurement errors of measurement results of mass concentrations of toxic substances (alcohol) in biological objects (urine, blood) and water. Two ways of establishing the value of the certified characteristic – mass consentration of propanol-1 or propanol-2 have been studied. The results obtained by the preparation procedure and comparison with the standard are the same within the margin of error.


Author(s):  
Е. M. Serba ◽  
М. B. Overchenko ◽  
L. V. Rimareva ◽  
N. I. Ignatova ◽  
А. E. Orekhova ◽  
...  

In the production of alcohol in the preparation of grain raw materials for fermentation, the main role is given to enzyme preparations of amylolytic action, which are key enzymes that catalyze the hydrolysis of starch. Amylolytic enzyme preparations with a different composition of enzymes and their level of activity, a mechanism of biocatalytic effect on starch, and a range of thermal and pH optimum are widely represented on the Russian market. The development of optimal conditions for the preparation of grain wort, the rational selection and dosage of concentrated enzyme preparations, the properties of which correspond to the parameters of the technological process, will ensure the effective preparation of starch for fermentation, and increase the profitability of alcohol production. The aim of this work was to study the influence of enzyme preparations of amylolytic action and the conditions of their use on the efficiency of the process of alcoholic fermentation and the yield of the final product, ethanol. The effect of various dosages of enzyme preparations of glucoamylase action, with a different ratio of the main enzyme glucoamylase and minor enzyme α-amylase, as well as methods for preparing wheat wort on the process of alcoholic fermentation, was studied. It was found that the enzyme preparation, the source of glucoamylase, in which α-amylase was present in a ratio of 15: 1 (in terms of activity level), turned out to be more effective in fermenting prepared wheat wort: its optimal dosage was 8 units. GLS / g starch. The presence of a sufficient amount of α-amylase in this preparation compensated for the dosage of thermostable α-amylase. The alcohol concentration in the mash was 10.2% vol., The alcohol yield was 67.9 cm3 / 100 g of starch. When glucoamylase with a lower ratio of the main and minor enzyme (75: 1) was used at the saccharification stage, an increase in the wort fermentation depth was observed with an increase in the concentration of glucoamylase to 9-10 units of GLS / g and α-amylase to 0.5 units. AC / g. It was also found that an increase in the duration of enzymatic-hydrolytic preparation of the wort had a positive effect on the fermentation process, the alcohol concentration in the mash increased to 10.2 vol.%. It was shown that the introduction of proteases into the wort helps to reduce the viscosity of grain wort, enriching it with assimilable yeast amino acids, which leads to an increase in the yield of alcohol. It has been confirmed that the synergy of the action of enzymes of amylolytic and proteolytic effects on polymers of grain raw materials allows to increase the efficiency of their conversion to ethanol. The conditions of enzymatic-hydrolytic processing of grain raw materials for fermentation are developed. The use of the digestion stage did not significantly affect the fermentation results of wheat wort.


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