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The paper reports on the production of the maral recombinant chymosin in the Escherichia coli expression system (SHaffle express strain) and the study of its biochemical properties relevant for the cheese-making industry. The highest maral recombinant prochymosin content in inclusion bodies was observed when producer cells were cultured at 25°C for 6 h after the introduction of an inducer, 10 mM isopropyl-β-D-1-thiogalactopyranoside. The biochemical properties of the obtained enzyme were compared with those of bovine and dromedarian recombinant chymosins. It is shown that total proteolytic activity of the maral recombinant chymosin was comparable with that of the bovine enzyme and that it exceeded the activity of the dromedarian enzyme by about 3.8 times. The thermal stability of the recombinant chymosin from maral was found to be 5–10°C higher than that of the chymosins from the cow and dromedary. The patterns of dependence of milk-clotting activity on the pH level and calcium chloride concentration in cow’s milk on the enzyme from maral met the requirements set by the cheese industry. Its high proteolytic activity and thermal stability limits the scope of application of maral recombinant chymosin to the production of cheeses with short ripening and short storage times.

The review discusses the basic biochemical properties of the known recombinant chymosins that are currently used in cheesemaking or may potentially be used as industrial milk coagulants. The parameters of the Michaelis–Menten kinetics, milk-clotting activity, proteolytic activity, specificity, and the dependence of coagulation ability on pH and calcium-ion concentration are considered.

This paper discusses biochemical properties of the recombinant chymosin in alpaca (Vicugnapacos), which influence the production of rennet cheeses. These properties determine its value in the production of rennet cheeses. Recombinant bovine chymosins are used as a control. In comparison to them, the recombinant alpaca chymosin is characterized by a high specificity towards bovine κ-casein: the threshold for its thermal inactivation is 10–15°C higher and reaches 60°C. The nature of the relation of its specific activity to the pH and concentration of CaCl meets the requirements for the use of milk-clotting enzymes in the production of rennet cheeses.

The article is devoted to the studying the processes of establishing oscillations in the generator on backward wave. The superregenerative mode has been considered within the framework of the linear theory. In the analysis, a complex frequency is introduced, the imaginary part of which characterizes the increase in oscillations over time. One of the main peculiarities of considered two-dimensional model is accounting focusing magnetic field effect. In the presence of longitudinal magnetic field of finite magnitude the transverse high frequency displacements in electron beam occur in addition to the longitudinal ones. The method of successive approximations has been used in analysis. The case of cyclotron resonance is considered separately, when only a slow cyclotron wave is excited in the electron beam, which noticeably simplifies the original problem and the initial relations.

We report the results of studying the polarisation manifestations of laser autofluorescence of optically anisotropic structures in biological tissues. A Mueller-matrix model is proposed to describe their complex anisotropy (linear and circular birefringence, linear and circular dichroism). The relationship is established between the mechanisms of optical anisotropy and polarisation manifestations of laser autofluorescence of histological sections of rectal tissue biopsy in different spectral regions. The ranges of changes in the statistical moments of the 1st-to-4th orders, which describe the distribution of the azimuth-invariant elements of Mueller matrices of rectal tissue autofluorescence, are found. Effectiveness of laser autofluorescence polarimetry is determined and the histological sections of biopsy of benign (polyp) and malignant (adenocarcinoma) tumours of the rectal wall are differentiated for the first time.

This research presents investigation results of the diagnostic efficiency of an azimuthally stable Mueller-matrix method of analysis of laser autofluorescence of polycrystalline films of dried uterine cavity peritoneal fluid. A model of the generalized optical anisotropy of films of dried peritoneal fluid is proposed in order to define the processes of laser autofluorescence. The influence of complex mechanisms of both phase (linear and circular birefringence) and amplitude (linear and circular dichroism) anisotropies is taken into consideration. The interconnections between the azimuthally stable Mueller-matrix elements characterizing laser autofluorescence and different mechanisms of optical anisotropy are determined. The statistical analysis of coordinate distributions of such Mueller-matrix rotation invariants is proposed. Thereupon the quantitative criteria (statistic moments of the first to the fourth order) of differentiation of polycrystalline films of dried peritoneal fluid, group 1 (healthy donors) and group 2 (uterus endometriosis patients), are determined.

A new information optical technique of diagnostics of the structure of polycrystalline films of blood plasma is proposed. The model of Mueller-matrix description of mechanisms of optical anisotropy of such objects as optical activity, birefringence, as well as linear and circular dichroism is suggested. The ensemble of informationally topical azimuthally stable Mueller-matrix invariants is determined. Within the statistical analysis of such parameters distributions the objective criteria of differentiation of films of blood plasma taken from healthy women and breast cancer patients were determined. From the point of view of probative medicine the operational characteristics (sensitivity, specificity and accuracy) of the information-optical method of Mueller-matrix mapping of polycrystalline films of blood plasma were found and its efficiency in diagnostics of breast cancer was demonstrated. Considered the prospects of applying the method in experimental medicine for differentiation of tissues of internal organs of healthy and diabetic rats.

The optical model of polycrystalline networks of histological sections of rectum wall is suggested. The results of investigating the interrelation between the values of statistical (statistical moments of the 1st-4th order) parameters are presented. They characterize the coordinate distributions of the fourth parameter of Stokes vector of Fourier transforms of laser images of rectum wall histological sections and oncological changes. The diagnostic criteria of rectum cancer are determined.

This paper presents analysis of a proposed series hybrid configuration suitable for use in a transit bus. A model of an existing vehicle drivetrain is validated against experimental data collected over an eight month period. Modeling the vehicle with a flywheel energy storage system, a corresponding control scheme for the generator is proposed. Based on the recorded driving conditions, a series of simulations are conducted to verify the feasibility and performance of the proposed design. Based on the simulation results, an economic comparison between the proposed and original design is provided demonstrating the economic advantage of the proposed design.

Voltage sags, also known as dips, are increasingly important to industrial reliability. Modern process controls are often sensitive to voltage sags. The combination of a voltage sag and sensitive equipment may cause significant production outages. Less sensitive equipment may be available at a premium price, but the designer must know the sag characteristics of the electric system to make the best choices between reliability and cost. This proposed chapter offers a way to predict voltage sag performance without long term monitoring and before plants are constructed. The analysis technique proposed for a new chapter 9 in the next revision of IEEE std 493 is shown. >

The PWM asymmetrical half-bridge is used to control the output current of a three-phase diode rectifier with a capacitor smoothed output voltage. The controlled-current function provided by the bridge improves the performance of the rectifier by lowering the low frequency ripple in the diode rectifier output current and by maintaining a balanced AC supply current when the AC supply voltage is unbalanced. The two-switch asymmetrical bridge can be designed with low per-unit voltage ratings, typically 15%, and can guarantee equal current sharing between parallel rectifiers. The higher conduction losses introduced by the bridge is offset by the improved diode rectifier performance, the low voltage devices used in the bridge, and the use of smaller L-C filter components. Balanced UPF sinusoidal supply currents can be obtained by using a three-phase bi-directional Y-switch and two asymmetrical half-bridges to separately control the output currents at both the diode rectifier output terminals. The asymmetrical bridge switches are exposed to only half the rectifier output voltage and the three-phase Y-switch has very low rms per-unit current ratings.

This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections, cytological smears) in the task of diagnostics and differentiation of early stages of cancer: Dysplasia — cervical microinvasive carcinoma of cervix uteri. The analytical conditions of polarization-optimal probing of biological layers were determined basing on the model of linear birefringence and dichroism of birefringent (fibrillar, porphyrin) networks. The technique of polarization-variable laser autofluorescence was developed and experimentally tested. The objective criteria (statistical moments) of differentiation of histological sections autofluorescent images of endometrium biopsy and cytological smears of it mucous coat were defined. The operational characteristics (sensitivity, specificity, accuracy) of this technique were determined concerning the positions of probative medicine, and clinical efficiency.

The results of singular approach usage in the tasks of description and classification of appearance of optical anisotropy of different types of phase-inhomogeneous biological layers (surface-scattering, optically thin and optically thick) have been presented. The characteristic values of the fourth Stokes vector parameter (S4= 0 — linear polarization — (L-state); S4= ±1 — circular polarization — (±C-state)) have been chosen as the main analytical tool describing polarization-singular states. The value of S4has been determined by the value of phase shift between the orthogonal components of amplitude in the point of biological layer laser image and therefore is azimuthally stable. Hence, statistic moments of the first to the fourth orders characterizing the distribution of the amount of characteristic values S4= 0; S4= ±1 have been used for definition and differentiation of optical properties of different types of biological layers — surface scattering, optically thin and optically thick human skin.

We present in this work the results of an investigation to analyse the coordinate distributions of azimuths and ellipticity of polarization (polarization maps) in laser images of blood plasma layers for three groups of patients: healthy (group 1), mastopathy (group 2) and breast cancer (group 3). To characterize polarization maps for all groups of samples we use three groups of parameters: statistical moments of the first to fourth orders, autocorrelation functions and logarithmic dependences for power spectra related to distributions of azimuths and ellipticity of polarization inherent to laser images of blood plasma. We ascertain the criteria for diagnosis and differentiation of pathological changes of the breast.

The three-dimensional heat-conduction problem is solved for a multilayer domain with a local source in one of the layers. The numerical results of the solution are analyzed in application to the layered structure of a semiconductor integrated circuit.