The paper describes an algorithm for determining reasonable dimensions of an upset ingot during computer-aided design of shaft press-forging under fuzzy goals. Fuzzy goals related to product metal ...elaboration quality and the complexity of its manufacture are formulated. Objective values of a design parameter for each goal are determined. Membership functions for possible solutions corresponding to these goals and the rule of choosing the most reasonable solution are constructed. Two examples of solving the problem depending on the selected goals are given. The proposed algorithm allows one to choose the most reasonable solution from a set of feasible ones and reduces human participation in the computer-aided design process. The developed approach can be applied to solving other problems of press forging, such as choosing an ingot, determining the necessity of the billet upset operation, determining the cogged billet dimensions, etc.
A relationship between the nonmonotonic concentration dependences of the size of the dispersed phase (nanoassociates), physicochemical properties (electric conductivity, pH, redox potential), and ...fertility of hydrobionts under the action of solutions of citric (CA) and succinic (SA) acids in low concentrations was established. Solutions of CA stimulate the fertility of
Paramecium caudatum
infusoria and
Chlorella vulgaris
algae in a wide range of formation of domains and nanoassociates (1•10
–13
–1•10
–5
mol L
–1
), whereas solutions of SA exert almost no effect on the fertility and slightly inhibit it only in a range of nanoassociate formation at the calculated concentrations from 1•10
–17
to 1•10
–14
mol L
–1
.
Electrochemical and transport characteristics of systems equipped with OPMN-P and OFAM-K membranes during operation in electronanofiltration cell are studied experimentally. The reasons for changes ...in the characteristics of membrane systems under the influence of various factors in the process of electronanofiltration of solutions that simulate the ionic composition of the ammonium-nitrate- and potassium-sulfate-containing solutions from electroplating and mineral fertilizers production, as well as the process media of the Livshits АО ТАGAT electroplating plant, are revealed. The change in the local conductivity of the solution in the intermembrane channel and, as a consequence, the increase in current density at the studied solution electronanofiltration is shown to be connected with the flow restriction in the electrochemical cell and the solution heating. Analysis of the systems’ electrochemical characteristics during the electronanofiltration the galvanic-production process media gave the degradation range of the OPMN-P semi-permeable membrane active layer (15–30 V) because of surplus of the operation range certified value pH > 12. Improving of the transport characteristics of membrane systems during electronanofiltration of aqueous solutions (ammonium nitrate, and potassium sulfate) is associated with the increase in the pressure differential. Increase of the voltage in the electronanofiltration cell leads to decrease in the outlet flow for the near-anodic membrane OFAM-K and increase in the outlet flow for the near-cathoduc membrane OPMN-P. This is associated with the displacement of the pH value of the near-anodic permeate toward acidic environment; of the near-cathodic permeate, toward alkaline environment. It is found that during the electronanofiltration of the electroplating process media the surface of the near-cathodic membrane OPMN-P is coated with the Fe(OH)
2
and Fe(OH)
3
precipitates due to supersaturation. The precipitates act as an absorber of Zn
2+
, Zn(OH)
4
2–
, and other ions at a constant pressure differential
P
= 1.6 MPa, which leads to the dynamic membrane formation. Empirical equations for the calculating of the specific outlet flux and the retention coefficient are proposed basing on the analysis of experimental data obtained during the membrane separation of the studied solutions under the action of the pressure differential and voltage.
Based on experimental data obtained using a combination of physicochemical techniques (dynamic light scattering, microelectrophoresis, conductivity, surface tension, pH, dielectric constant, ...polarimetric measurements, atomic force microscopy, and UV and EPR spectroscopy) a previously unknown fundamental phenomenon was discovered: the formation of nanometer-sized molecular assemblies (nanoassociates) in low-concentration aqueous solution, which were prepared by serial dilution. The formation and rearrangement of nanoassociates in solutions of different concentrations can be considered as a major factor controlling the physicochemical and, probably, specific biological properties of diluted aqueous solutions. The formation of nanoassociates is triggered by the solute under certain conditions, the most important of which are the specific solute structure, the presence of external physical fields (geomagnetic and low-frequency electromagnetic), and the solution preparation procedure.
The design of a tubular-type electrobaromembrane apparatus for cleaning of industrial solutions of machine-building and chemical industries is developed. An optimized version of the apparatus and a ...method for calculating the volumes of its elements and mass are presented. The developed design of the apparatus makes it possible to increase the productivity and quality of separation of solutions, to turbulize and cool the separated (initial) solution.
The NEMO-3 results for the double-
β
decay of
150
Nd to the 0
1
+
and 2
1
+
excited states of
150
Sm are reported. The data recorded during 5.25 year with 36.6 g of the isotope
150
Nd are used in the ...analysis. The signal of the
2
ν
β
β
transition to the 0
1
+
excited state is detected with a statistical significance exceeding 5
σ
. The half-life is measured to be
T
1
/
2
2
ν
β
β
(
0
1
+
)
=
1
.
11
-
0.14
+
0.19
stat
-
0.15
+
0.17
syst
×
10
20
year, which is the most precise value that has been measured to date. 90% confidence-level limits are set for the other decay modes. For the
2
ν
β
β
decay to the 2
1
+
level the limit is
T
1
/
2
2
ν
β
β
(
2
1
+
)
>
2.42
×
10
20
year
. The limits on the
0
ν
β
β
decay to the 0
1
+
and 2
1
+
levels of
150
Sm are significantly improved to
T
1
/
2
0
ν
β
β
(
0
1
+
)
>
1.36
×
10
22
year
and
T
1
/
2
0
ν
β
β
(
2
1
+
)
>
1.26
×
10
22
year
.
In this paper, we study the structure of the surface layer of air-dry, water-saturated, and operating samples of microfiltration composite membranes based on MMK-0.45 polyamide and MFFC-2G ...fluoroplast using infrared (IR) spectroscopy. The IR spectra are analyzed in the frequency ranges of 500–1700 and 2800–3400 cm
–1
. In the case of polyamide membrane MMK-0.45, the main peaks of the functional groups of polymers in the IR spectra of dry, water-saturated, and operating samples coincide. The absorption bands of polyamides range from 650 to 5000 cm
–1
, corresponding to the peptide bond. Bending vibrations of the carbonyl group occur in the absorption band at 1650 cm
–1
while bending vibrations of the N–H bond are observed in the band at 1550 cm
–1
. The 3500–3000 cm
–1
region is the stretching vibrations of the NH, OH, and water groups. In the case of the operating sample of the MFFC-2G fluoroplastic membrane, the stretching vibrations of the fluorine-substituted groups lie in the range of 1100–1400 cm
–1
; they correspond to the C–F stretching vibrations (1198 and 1171 cm
–1
). The IR spectrum also shows two peaks in the region of 2800–3000 cm
–1
; they are characteristic of biodiesel from vegetable oils. The specific output flow and changes in the pH of the permeate depending on time and transmembrane pressure are studied. There are several periods of decrease in the specific output flow depending on time, which is most likely due to the unblocking of pores of the microfiltration membrane by substances in the solution being separated, and the possible formation of a boundary gel layer. The decrease in the pH of the permeate with an increase in the transmembrane pressure on the MMK-0.45 and MFFC-2G microfiltration membranes is due probably to an increase in the rate of migration of organic acids through the helium layer and the operating layer of the membrane.
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