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From the expression (8) follows that on size of force R ^ aspiring it is pushed out soils an occipital facet of a wedge, the greatest influence is rendered by thickness of an occipital facet of a wedge.
Analyses showed [3, 328-330] that the greatest widths of an occipital facet, admissible at work of ploughs at soil plough were in limits 6...11 mm.
Being based on this data, it is possible to define a limiting thickness of a wedge 28
5 = e ■ sim (11)
Where: e — length of a facet, mm.
Slope, e = 8mm, i = 22,5°wehave51 = 8 • sin22,5° = 3,06mm. Being based on these calculations it is possible to believe that stability of a course is similar a knife wedge is provided, if its thickness 28 is in limits of 6,12 mm.
5 3,06 Then sim = — = —— = 0,3825 e 8
i = arcsin0,3 8 25 = 22,50 (12)
It is considered [3, 324-326] that the corner y should be such that at knife movement cutting with sliding along cutting edges was carried out AO (fig. 2).
That the soil did not gather in a heap, it is necessary to meet condition Т > F, after statement ofvalue of forces leads to a following inequality
Y>900+ 9c (13)
Where: Т — force of resistance to shift; F- force of a friction. Analyses have shown that at 2i = 45° for various values of a corner of a friction of soil on steels, a corner y is in limits 135°-152°.
As a conclusion, at movement of a knife with an occurrence obtuse angle in soil that cutting with the sliding was carried out, the necessary corner of occurrence of a wedge should be within 1350-1520, thickness of a wedge of within 6 sm and the corner of its point 2i within 44° ... 46°.
References:
1. Rudakov G. M. Osnovi mehanizaci seva hlopchatnika. - T. "Fan", - 1974.
2. Nurabaev B. U. Vibor tipa i obosnovanie osnovnih parametrov rabochega organa kultivatora dlya mejduryadnoy obrabotki. dis. kand. teh.nauk. Yangiyul, - 2006.
3. Sineokov G. N., Panov I. M. Teoriya i raschet pochvoobrabativayushih mashin. - M.: Mashinostroenie, - 1977.
DOI: http://dx.doi.org/10.20534/ESR-17-1.2-244-247
Shamsieva Makhbuba Badrievna, Senior scientific employee-researcher, Tashkent institute of textile and light industry, Republic of Uzbekistan
E-mail: [email protected] Kodirov Tulkin Jumaevich, Technical sciences associate, professor, Tashkent institute of textile and light industry, Republic of Uzbekistan
Chromatographic identification of esters on the basis of fatty acids with alcohols
Abstract: The conducted chromatographic identification of the ester. It identifies the main physic-chemical properties of the ester. Included in the ester are secondary products of local industries, and are available raw materials. Keywords: Greasing, ester, fat, gas-liquid chromatography, distilled fatty acid, fusel oil.
Currently, significantly increased the use of synthetic fatliquor- due to change and reduction the raw material base of natural fats. ing substances for the fattening of the various kinds of skins. This is However, synthetic fatliquoring cannot fully replace natural fats,
N = q^b (5)
3 2sim
i h q •52 • h
As b =-let s receive N 3 =--(6)
sina 3 2sini- sina
Force R forms with equally effective N a friction corner , therefore its size can be defined according to dependence
R =---(7)
2sim-sina • cosfa
Figure 3. The scheme to definition of pressure of soil on a nape of a knife in the form of a wedge
The lateral component of this force is equal
£ = q-82h C0Sit+*c] (8)
3y 2sim- sina- cos$c
Or Ry = 0,5 ■ q■S2h ■ sin a • (ctgi - tgfc) (9)
The horizontal component of this force is equal
Rsx = 0,5-q •82h • sin a • (tg$c • ctgi +1) (10)
Chromatographic identification of esters on the basis of fatty acids with alcohols
especially in the fatliquoring of leathers chrome tanning. In this regard, there is a need to study the possibility ofusing natural fats, not previously used for fattening of leather [1-2].
Gas-liquid chromatography is one of the fastest and most accurate method quantitative analysis ofvarious substances, including fats. The literature reports primarily on hydrolytic splitting of these substances. The hydrolysis of fats is carried out in hard conditions with elevated temperature and leads to various artifacts [3]. So, formed during the hydrolysis of fats, fatty acids undergo a series of transformations, the depth ofwhich depends on the structure of the acid and exposure to external factors [4], which in turn can be the cause of the distortion of the results of the GLC.
In recent years, studies on the replacement of natural food and fats used in the manufacture of leather, synthetic fatliquoring agents. The main problem is obtaining synthetic fatliquoring substances that are similar in structure and composition to natural fats. Such natural fatliquoring materials, such as fish oil, technical fats and oils are mixed triglycerides, composed of various saturated and unsaturated fatty acids. The compositions of the synthetic
Table 1. - The main physic-c
fatliquoring substances can be directed to change by varying the ratio of individual components, in particular of fatty acids. This requires knowledge of the qualitative and quantitative composition of natural fats.
One of the most rapid and accurate methods if quantitative analysis of components of fats: hydrocarbons, aliphatic alcohols, fatty acids, esters, etc. — is a gas-liquid partition chromatography. Mixtures of fatty are acids analyzing, translating them before the separation of methyl esters that are more volatile than the free acid, and not have the ability to time results [5].
The aim of this work was to study if the quantitative and qualitative composition of the obtained ester and the study of the application of the method of gas-liquid chromatography for the analysis of fats contained in the skin.
Research synthesized esters on the basis of isoamyl alcohol and oleic acid, also the ester of distilled fatty acids with fusel oil.
A preliminary analysis of the samples of esters was performed according to standard procedures. The results of the analysis are given in table. 1.
mical properties of the ester
№ Parameter Ester on the basis
isoamyl alcohol and oleic acid isoamyl alcohol and oleic acid
1 Moisture and volatile substances,% 6,0 2,8
2 Acid number, mg KOH/g 15,52 89,9
3 Iodine number 34,7 31,9
Fat acid composition was determined by gas-liquid chromatography. For the separation of fatty acids with a large number of carbon atoms used the method of inter etherification with methanol in the presence of a catalyst of potassium hydroxide.
Gas chromatographic analysis was performed on the device «Chrome 4» with the thermal conductivity detector in isother-
mal mode under the following conditions: steel spiral column length of 2.75 m and a diameter of 3 mm filled chromos orb W (80-100 mesh.) with 10% E-30 as a stationary liquid phase, temperature of the evaporator 210, column 200, cathetometer 230 °C; carrier gas helium, 40 ml/min, the speed of the chart tape 240 mm/h, sample volume of 6 yl.
Figurel. Chromatogram of the ester on the basis of isoamyl alcohol and oleic acid
The resulting esters decomposed by 20% aqueous H2SO4 solution. Fatty acids were extracted three times with diethyl ether. Then the ether extract was washed with distilled water until neutral environment, dried over sodium sulfate, then the ether distilled. Fatty acids were methylamines diazomethane. The purification of the resulting methyl esters was carried out in a thin layer of silica gel in the solvent system hexane: ether: acetic acid (7:3:0,1), area of methyl esters were shown in pairs J2. The area of methyl esters from the silica gel was collected in a flask and methyl esters stripped of chloroform, which is then distilled. Methyl esters dissolved in hexane and analyzed on Agilent Technologies 6890 N with flame ionization detector using capillary column length of 30 m coated with
a non-polar phase HP-5 at a temperature of from 50 to 250 °C. Carrier gas — helium, 30 ml/min. identification of the esters was carried out by retention time model of methyl esters produced in the same conditions of gas-liquid chromatography.
In Fig. 1 and 2 show chromatograms of fatty acid entering the composition of the studied esters.
Peak identification was carried out both on the net standard methyl esters of fatty acids.
To determine the relative retained volume were calculated against the retention time of the analyzed acids by retention time of standard acid. Standard quality took the retention time of methyl ester of caprylic acid.
Analysis of FAMEs
In table 2. The qualitative and quantitative characteristics of the chromatogram of esters
Table 2. - Qualitative and quantitative characteristics of chromatograms esters
Peak# RetTime[min] Type Width, [min] Area [pA*s] Height [pA] Area %
Ester on the basis of isoamyl alcohol and oleic acid
1 2,536 BV 0,0304 3,42982 1,57356 0,66324
2 2,670 VP 0,0242 3,60654 2,18584 0,69741
3 2,850 VB 0,0248 10,06519 5,94011 1,94634
4 3,765 BB 0,0269 1,93937 1,08068 0,37502
5 9,621 BB 0,0439 12,22303 4,32937 2,36361
6 13,723 BV 0,0461 6,00510 2,11894 1,16123
7 14,218 BB 0,0477 202,44965 64,36129 39,14842
8 17,984 BV 0,0543 23,18252 6,71003 4,48289
9 18,124 W 0,0475 146,28067 45,45841 28,28682
10 18,279 VB 0,0694 33,83310 6,13316 6,54243
11 18,702 BP 0,0503 49,62173 15,53219 9,59553
12 27,134 BP 0,0532 9,65382 2,73345 1,86679
13 29,196 BP 0,0477 3,91331 1,12180 0,75673
14 33,515 BP 0,0615 10,92973 2,38160 2,11352
Totals: 517,13359 161,66044
Ester based on distilled fatty acids and fusel oil
1 2.533 BV 0.0187 4.00287 3.39923 0.58614
2 2.559 w 0.0181 2.91229 2.41709 0.42645
3 2.607 vv 0.0271 3.78267 1.99272 0.55390
4 2.667 VP 0.0253 7.79235 4.71795 1.14103
5 2.846 VB 0.0252 22.43686 12.95105 3.28543
6 2.990 w 0.0241 1.85107 1.12871 0.27105
7 3.034 VP 0.0366 3.39705 1.33699 0.49743
8 3.515 VB 0.0311 2.25341 1.09140 0.32997
9 3.759 BB 0.0286 4.35020 2.35006 0.63700
10 9.614 BB 0.0445 10.83164 3.77702 1.58608
11 13.718 pp 0.0393 2.81296 1.04896 0.41190
12 14.220 BP 0.0502 330.52432 103.62777 48.39862
13 17.982 BV 0.0529 51.28445 13.95032 7.50957
14 18.120 w 0.0513 136.61314 39.58712 20.00424
15 18.268 VB 0.0655 48.18110 9.44490 7.05515
16 18.695 BB 0.0489 33.09858 9.93589 4.84662
17 27.139 BP 0.0485 12.97935 3.74252 1.90056
18 29.193 BB 0.0443 3.81656 1.16289 0.55886
Totals: 682.92090 217.66259
fidl a, (20160518) sig10140.d
T-1—I—I—I--1—I-r 1-1-1-1-1-1-1-1-1 H—I—I-1-1—r
5 10 15 20 25 30
Figure 2. Chromatogram of the ester on the basis of distilled fatty acids and fusel oil
New aspects of reliability function of irrigation pumping stations
For the quantitative determination of the content of each fatty On the basis of the conducted analyses were the main composi-
acid in the mixture using the method of internal normalization of tion, calculated mass fractions of the individual components of the the areas of the peaks take the sum of the areas of all peaks as 100%. fatty acids included in the ester are shown in table 1-2.
Table 2. - The compositions of the major fatty acids are constituent into ester
№ Fatty acid Code acid, С ' n Ester on the basis
isoamyl alcohol and oleic acid distilled fatty acids and fusel oil
1 Myristinic acid C 2,77 1,90
2 Palmitoleic acid C16:1 1,36 0,50
3 Palmitic acid C C16:0 46,06 58,50
4 Stearic acid C C18:0 11,28 5,85
5 Oleic acid C18:1 32,26 24,18
6 Linoleic acid C C18:2 5,27 9,07
£ , = fatty acids saturated ' 60,11 66,215
£ ,= fatty acids unsaturated ' 39,89 33,75
According to the analytical thin-layer chromatography on Silu- acids in roughly equal numbers. fol plates in the solvent system hexane: ether: acetic acid (7:3:0,1) Thus, it can be argued that the studied Kanye esters on the basis
in the sample of air on the basis of isoamyl alcohol and oleic acid are of isoamyl alcohol with oleic acid and distilled fatty acid with a fusel
present mainly esters of fatty acids, also, in the sample of air based oil saturated and unsaturated fatty acids predominantly of a series
on the distilled fatty acid with a fusel oil is present, the same fatty of C16- C .
References:
1. Шамсиева М. Б., Кодиров Т. Ж. Применение этерификата на основе местных вторичных продутов для жирования кожевенных полфабрикатов.//Проблемы текстиля. - Ташкент. - 2016. - № 1.
2. Шамсиева М. Б., Джураев А. М., Кодиров Т. Ж., Абдурахмонова П. Э. Исследование термодеформационных свойств изменений кож обработанных новыми жирующими и гидрофобизирующими композициями.//Сиентия. - Москва. - 2016. - № 3. сентябрь.
3. Микеш О. Лабораторное руководство по хроматографическим и смежным методам. - М., Мир., - 1982, - ч. 2. - 783 с.
4. Маньковская Н. К. Синтетические жирные кислоты. - М., - Химия, - 1965. - 168 с.
5. Houis I. P. и др. Тонкослойная хроматография для качественного и количественного анализа жирующих веществ, содержащихся в коже/Houis I. P., Pore I. Fechnicuir, - № 10, - С. 186-187.
DOI: http://dx.doi.org/10.20534/ESR-17-1.2-247-249
Ergashev Rustam Rahimovich, PhD of technical sciences, Associate professor of Tashkent Institute of Irrigation and Melioration, Republic of Uzbekistan
E-mail: [email protected]
New aspects of reliability function of irrigation pumping stations
Abstract: This paper presents problems of safety of operation of pumping stations. In particular, the security conditions of the pumps, pumping water contaminated with oil, fins, dust, mineral products are given.
Keywords: reliability, safety, wear, pumping station, equipment, destruction, fin, environmental requirements.
As you know, the creation of a network of irrigation in arid zone is associated with the development of an irrigation machine. Safety of operation of pumping stations (PS) can be achieved through the implementation of the set of conditions, ensuring minimum impact on the external National Assembly (NA) related to the state of water resources and the impact of the National Assembly themselves on environmental objects. Because ultimately, the construction and operation of the entire complex hydraulic structures is carried out for the management of water resources in order to improve people's quality of life.
Among the conditions ofsafety ofoperation ofthe complex include: • The amount of water needed for the sustainable functioning of the structures related to water consumption. Violation of the efficiency of operation of the National Assembly, caused by a shortage
of water resources directly affects the reception of food, and other components of the quality of life of the population. Particularly acute, this problem in our country, where a lot of the water sources is transboundary waters.
• High-quality water resources. On the functioning of the National Assembly of resistance affects the chemical composition and properties of water. When the consumption of water in the various processes may be failure of the material with which it is in contact.
When operating in the National Assembly enters water sources, as is commonly believed, the regulatory clean water, with a high temperature regime. However, water is, contaminated oils, fin, dust, mineral products. Even if their content of the water does not exceed the maximum permissible concentration norms and other regula-
