Modelling of Liquid-Liquid Equilibria Using NRTL and UNIFAC Equations in the Extraction of Bio-Oil-Based Phenolics Produced from the Pyrolysis of Sugarcane Bagasse

An exploration on renewable energy resources has been paid more attention due to the depletion of the fossil-based energy resource. In addition, their safe and environmentally friendly properties have attracted experts’ interest. One of the renewable energy resources is the bio-oil produced from sugarcane bagasse. The bio-oil was produced through a pyrolysis at 500°C. However, the produced bio-oil showed a high content of phenolics, c.a. 40-60%. A liquid-liquid extraction to remove the phenolics using methanol-chloroform solvents would be beneficial to improve the stability of the bio-oil as well as to obtain high purity phenolics. Modelling of the liquid-liquid equilibria in the extraction was then developed using NRTL and UNIFAC equations. The empirical quantitative data of phase equilibrium system were calculated on both the extract and raffinate phases. The lowest RMSD value of 0.043160 was obtained from the calculations using NRTL equation at an extraction temperature of 50°C. Thus, the most suitable model was achieved using NRTL equation.

Using Unnatural Protein Fusions to Engineer a Coenzyme Self-Sufficiency System for D-Phenyllactic Acid Biosynthesis in Escherichia coli

The biosynthetic production of D-penyllactic acid (D-PLA) is often affected by insufficient supply and regeneration of cofactors, leading to high production cost, and difficulty in industrialization. In this study, a D-lactate dehydrogenase (D-LDH) and glycerol dehydrogenase (GlyDH) co-expression system was constructed to achieve coenzyme NADH self-sufficiency and sustainable production of D-PLA. Using glycerol and sodium phenylpyruvate (PPA) as co-substrate, the E. coli BL21 (DE3) harboring a plasmid to co-express LfD-LDH and BmGlyDH produced 3.95 g/L D-PLA with a yield of 0.78 g/g PPA, similar to previous studies. Then, flexible linkers were used to construct fusion proteins composing of D-LDH and GlyDH. Under the optimal conditions, 5.87 g/L D-PLA was produced by expressing LfD-LDH-l3-BmGlyDH with a yield of 0.97 g/g PPA, which was 59.3% increased compared to expression of LfD-LDH. In a scaled-up reaction, a productivity of 5.83 g/L/h was reached. In this study, improving the bio-catalytic efficiency by artificial redox self-equilibrium system with a bifunctional fusion protein could reduce the bio-production cost of D-PLA, making this bio-production of D-PLA a more promising industrial technology.

Non-equilibrium dynamics of a scalar field with quantum backreaction

We study the dynamical evolution of coupled one- and two-point functions of a scalar field in the 2PI framework at the Hartree approximation, including backreaction from out-of-equilibrium modes. We renormalize the 2PI equations of motion in an on-shell scheme in terms of physical parameters. We present the Hartree-resummed renormalized effective potential at finite temperature and critically discuss the role of the effective potential in a non-equilibrium system. We follow the decay and thermalization of a scalar field from an initial cold state with all energy stored in the potential, into a fully thermalized system with a finite temperature. We identify the non-perturbative processes of parametric resonance and spinodal instability taking place during the reheating stage. In particular we study the unstable modes in the region where the vacuum 1PI effective action becomes complex and show that such spinodal modes can have a dramatic effect on the evolution of the one-point function. Our methods can be easily adapted to simulate reheating at the end of inflation.

Non-equilibrium phase transition at a critical point of human blood

Blood is the basic medium in the existence, evolution and physiological balance of animals and represents the biochemical “Internet” of the body; at least human blood exhibit the presence of an emergent phase that is highly unusual. Homeostasis, the state of the optimal functioning of the body, is maintained in living organisms by many chemical and physical conditions, particularly temperature. However, no regulatory mechanism has been identified that has led to a predetermined (molecularly encoded) optimal, individually variable, very specific temperature of around 36 °C. Additionally, the homeostatic temperature range, which is kept within predetermined limits, is merely an empirical fact. In the following, I will show that the reference temperature that is necessary to achieve homeostasis can be established, and a preset homeostatic range can be determined, using an original experimental method and refined tools of mathematical physics related to the nonlinear measures of the complexity of human blood. Moreover, signatures of a macroscopic coherent state in a non-equilibrium system at a critical temperature are obtained.

Interfacial Behavior of Solid- and Liquid-like Polyelectrolyte Complexes as a Function of Charge Stoichiometry

We systematically investigate in this work the surface activity of polyelectrolyte complex (PECs) suspensions as a function of the molar charge ratio Z (= [-]/[+]) from two model systems: the weakly and strongly interacting poly (diallyldimethylammonium chloride)/poly (acrylic acid sodium salt) (PDADMAC/PANa) and poly (diallyldimethylammonium chloride)/poly (sodium 4- styrenesulfonate) (PDADMAC/PSSNa) pairs, respectively. For both systems, the PEC surface tension decreases as the system approaches charge stoichiometry (Z = 1) whenever the complexation occurs in the presence of excess PDADMAC (Z < 1) or excess polyanion (Z > 1) consistent with an increased level of charge neutralization of PEs forming increasingly hydrophobic and neutral surface-active species. The behavior at stoichiometry (Z = 1) is also particularly informative about the physical nature of the complexes. The PDADMAC/PANa system undergoes a liquid–liquid phase transition through the formation of coacervate microdroplets in equilibrium with macroions remaining in solution. In the PDADMAC/PSSNa system, the surface tension of the supernatant was close to that of pure water, suggesting that the PSSNa-based complexes have completely sedimented, consistent with a complete liquid–solid phase separation of an out-of-equilibrium system. Besides, the high sensitivity of surface tension measurements, which can detect the presence of trace amounts of aggregates and other precursors in the supernatant, allows for very accurate determination of the exact charge stoichiometry of the complexes. Finally, the very low water/water interfacial tension that develops between the dilute phase and the denser coacervate phase in the PDADAMAC/PANa system was measured using the generalized Young–Laplace method to complete the full characterization of both systems. The overall study showed that simple surface tension measurements can be a very sensitive tool to characterize, discriminate, and better understand the formation mechanism of the different structures encountered during the formation of PECs.

Research and Design of Active Equalization System for Multi-stage Series Li-ion Battery

In view of the obvious phenomenon of the difference between the single cells of the series battery pack after multiple cycles of recycling, it is necessary to adopt balanced control to extend the working life of the battery pack, improve the energy utilization rate, and ensure the safety and stability of the battery pack. This paper proposes a single battery voltage as the control variable, adopts staged equalization, charge-discharge two-level equalization protection and isolated flyback converter circuit to realize the active equalization of battery pack energy, and designs the corresponding equalization control circuit. Through the comparison of a variety of control methods, the application of this system can achieve the final voltage balance. Tests show that the proposed equilibrium system can make full use of the larger capacity monomers, quickly improve the energy imbalance in the battery pack, and can effectively extend the working life of the battery pack and improve energy utilization.

Physics of evolution and unity of physics

The article considers the question of the possibility of constructing classical mechanics and empirical branches of physics, such as thermodynamics, statistical physics and kinetics on a general theoretical basis. The principles of constructing mechanics, thermodynamics, statistical physics, and kinetics are briefly given. It is shown how the construction of the above sections of physics on a unified basis became possible, relying on the mechanics of a structured body. The essence of this mechanics is that, unlike Newton’s mechanics, built for a body model in the form of a material point, this mechanics is built based on a body model in the form of a structured body. Moreover, the structured body is specified in the form of an equilibrium system of potentially interacting material points. It is shown how the equation of motion of a structured body is derived. The peculiarity of this equation is that it takes into account the transformation of the energy of motion of a structured body into internal energy when it moves in an inhomogeneous field of forces. This makes it possible to describe dissipative processes within the framework of the mechanics of a structured body without invoking statistical laws. Examples are given of how the empirical principles of the phenomenological branches of physics directly follow from the fundamental laws of physics.

Vestibular Rehabilitatiоn in Vestibular Migraine

The search for possible ways to minimize dizziness in patients with vestibular migraine is especially relevant in the aspect of individualized complex vestibular rehabilitation. Aim. To study the possibilities of complex individualized vestibular rehabilitation in patients with vestibular migraine. Material and methods. The study included 122 patients (40 men and 82 women) aged 18 to 50 years, with significant vestibular migraine. We used the Dizziness Handicap Inventory scale for assessing dizziness and a 5-point Scale for subjective assessment of the severity of dizziness and a special complex method including a set of vestibular exercises, a method of the computer stabilometry with biofeedback. Objective control of vestibular rehabilitation was carried out with the help of stabilometric testing. Results and discussion. Positive dynamics were observed when analyzing the data of the physical, functional and emotional subscales of the Dizziness Handicap Inventory and the Scale of Subjective Assessment of the Dizziness Severity. In addition, the presented stabilometric diagnostics made it possible to fix the difference between the initial condition of patients with vestibular dysfunction and after 3 months of the special vestibular rehabilitation.Тhere was a statistically significant decrease in the basic stabilometric parameters: the area of the statokinesiogram (median area, mm² – 254 (95% CI 222-285)) and the rate of deviation of the center of pressure (median speed, mm/s – 21 (95% CI 17-24)) as well as a decrease in the shifts of the spectrum energy in the low-frequency and high-frequency spectrum that indicates an improvement in stability. The presented method for influencing the compensatorycapabilities of regulatory mechanisms in patients with vestibular migraine positively affects the efficiency of the equilibrium system as a whole, optimizing postural stability in this category of patients. Conclusion. An individually selected comprehensive program of vestibular gymnastics and hardware rehabilitation techniques on the stabilographic platform with biofeedback helps to improve postural stability and minimize dizziness in patients with vestibular migraine.