On Preparation of Crystalline MgO-Ceramics from Amorphous Precursors

1993 ◽  
Vol 321 ◽  
Author(s):  
H. Jost ◽  
Ch. Carius ◽  
B. Peplinski

ABSTRACTAmorphous precursors are obtained as a result of the precipitation from magnesium acetate solutions with ammonia in the presence of citric acid. Compared with crystalline precursors they have a higher reactivity and a changed behaviour in calcination process as well as during sintering. Already at 1300 °C sintered pellets are achieved, whereas in technological process 1700 °C are needed.

Author(s):  
V. G. Prudnikov ◽  
◽  
H. L. Lysenko ◽  
I. M. Heida ◽  
A. L. Leppa ◽  
...  

The most common one of the «Pasta Filata» group is «Mozzarella», a soft Italian cheese that is now made from cow's milk and widely used in many dishes, especially as a pizza topping, which is the most popular food for young people. The paper substantiates the express technology for the production of soft cheese like «Mozzarella». The first batch of Mozzarella-type soft cheese was made using traditionally accepted technology. Another batch of cheese samples was made using express technology. In contrast to traditional technology, an aqueous solution of citric acid was added to the normalized mixture before making the main components, thereby instantly increasing the active acidity, which reduced the duration of the cheddarization process of the cheese mass. Other technological operations were similar to traditional technology. The research results show that during the production of experimental batches of cheese at the stage of cheese curd formation, the milk coagulation process in the samples obtained by traditional technology took an average of 42,3 min ± 1,45 min, whereas in the samples of experimental batch № 2, this process was much faster, only 15,7 min ± 2,40 min by adding an aqueous citric acid solution. The research results have established that the production of the soft cheese type «Mozzarella» by express technology leads to the reduction of the technological process, namely to decrease (by 9 times) the duration of cheddarization of the cheese mass which produces the necessary consistency (pH 5,3-5,2) for the further melting and stretching the cheese dough. The output of the finished product under the various technologies of production of soft «Mozzarella» cheese was almost at the same level. Thus, the weight of cheese of experimental batch № 1 on average was 829 g ± 12,66, respectively, the mass of cheese of batch № 2 - 847 g ± 14,36. The tasting assessment on a point scale showed that all tested cheese lots, regardless of the production technology had rather high points (41.8-42.0) and had perfect organoleptic characteristics that are typical for the type of cheese understudy and meets the standard requirements. In general, the analysis of these studies showed that the production of soft cheese, such as «Mozzarella» by the express technology, namely the use of citric acid leads to a minimal time of the cheddarization process. Reduces the clotting time of milk and the formation of the cheese mass of the necessary consistency for further melting and extraction, which in turn causes the technological process of production of the finished product to be reduced altogether.


2020 ◽  
Vol 140 ◽  
pp. 25-29
Author(s):  
K Akiyama ◽  
N Hirazawa ◽  
A Hatanaka

Oxytetracycline (OTC) has been commonly used as an effective antibiotic against various fish bacterial diseases, including vibriosis. In this study, the absorption-enhancing effect of citric acid on oral OTC pharmacokinetics and treatment of artificial Vibrio anguillarum infection was evaluated in juvenile yellowtail Seriola quinqueradiata followed by serum OTC concentration analysis. When 25 mg kg-1 body weight (BW) OTC was administered in combination with 1250 mg kg-1 BW citric acid, the serum OTC concentration reached almost the same concentration as that of the group treated with 50 mg kg-1 BW OTC. This coadministration successfully suppressed mortality due to vibriosis similar to the group treated with 50 mg kg-1 BW OTC. Conversely, poor efficacy was observed when only 25 mg kg-1 BW OTC was administered. These results suggest that coadministration of citric acid can be beneficial in reducing the dose of OTC needed for effective treatment, and thus contributes to the goal of reduced use of this antibiotic in aquaculture.


2020 ◽  
Vol 7 (2) ◽  
pp. 21-28
Author(s):  
SALI RADZHAPOV ◽  
◽  
RUSTAM RAKHIMOV ◽  
BEGJAN RADZHAPOV ◽  
MARS ZUFAROV

The article describes the developed radiometer for Express measurement of alpha radiation of radioactive elements based on a large-diameter silicon detector. The main element of the PPD detector is made using computer mathematical modeling of all stages of the technological process of manufacturing detectors, taking into account at each stage the degree of influence of the properties of the initial silicon on the electrophysical and radiometric characteristics of the detector. Detectors are manufactured for certain types of devices. The developed radiometer is designed to measure alpha radiation of natural isotopes (238U, 234U, 232Th, 226Ra, 222Rn, 218Po, 214Bi, etc.) in various environments. It also shows the principle of operation of the device, provides a block diagram of the measuring complex, describes the electronic components of the radiometer, as well as the block diagram. Signal transformations (spectrum transfer, filtering, accumulation) are implemented programmatically on the basis of a digital processing module. The device can detect the presence of specific elements in various environments, as well as protect people from the harmful effects of adverse radiation and can be used both in the field and stationary.


1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.


Author(s):  
S.B. Kudryashev ◽  
◽  
N.S. Assev ◽  
R.D. Belashov ◽  
V.A. Naumenko ◽  
...  

The article is devoted to solving one of the most important problems of the development of the sugar industry in Russia – the modernization of sugar production processes. Today, sugar production is actively being modernized, shifting most of its processes to the path of avomatization and optimization to improve the quality of products. This article describes one of the main ways to obtain information about the concentration of sucrose in syrup in the production of sugar.


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