Cavitation Solution Research Articles

Immunological efficacy of cavitated solutions in the complex therapy of chronic rhinitis

Quantitative and qualitative indicators of nasal lavages in patients with chronic rhinitis have been studied. The results of the study have shown that an increase in the number of viable neutrophilic granulocytes and in their lysosomal activity, a decrease in the activity and intensity of phagocytosis, inhibition of biocidal properties according to the spontaneous HCT test, and a decrease in the content of secretory IgA are recorded in patients with chronic rhinitis. The use of a 0.9 % sodium chloride cavitated solution led to the restoration of quantitative and qualitative indicators of innate immunity and some indicators of adaptive immunity in patients’ nasal secretions.

Treatment of infected wounds of the abdominal wall after mesh hernia repair

Background. An infected wound of the abdominal wall after mesh hernia repair is related to mesh infection, because mesh is situated at the bottom of the wound and granulation tissue doesn’t cover it. Infected mesh wounds have traditionally been treated by surgically removing the mesh which causes prolonged hospitalizations and hernia recurrence. Objective of the study is to increase the efficiency of treatment of wounds infection after mesh heria repair.
 Маterials and methods. We analyzed the results of wound infection treatment in 72 patients. 37 patients (group I) were treated according to the developed algorithm (ultrasound cavitation, VAC-therapy and decamethoxine solution), 35 (group II) were treated according to the traditional one (ultrasound cavitation, VAC-therapy and chlorhexidine digluconate solution).
 Results. The number of microbial colonies (CFU) in the wound decreased to lg (2.33 ± 0.51) CFU/ml and lg (1.35 ± 0.49) CFU/ml in group I against lg (4.01 ± 0) CFU/ml and lg (2.93 ± 0.56) CFU/ml in group II. (p < 0.01) The results of morphological examination of the wound edges confirmed more efficient growth of connective tissue in patients of group I (mesh was completely covered with granulation tissue) which improved wound healing. While in group II, mesh explantation was performed in 5 (14.3 %) patients (granulation tissue hasn’t covered mesh completely). The duration of wound healing in patients of group I was 16 ± 1.05 days, compared with 21 ± 1.2 days in group II (p < 0.01). We achieved better results through the use of the developed algorithm in group I, in particular the combination of ultrasound cavitation, VAC therapy and decametoxine solution, which has not only antimicrobial action, but also promotes connective tissue repair in the wound.
 Conclusion. Developed algorithm for wounds infection treatment after alloplasty, which includes ultrasound cavitation, VAC-therapy and decamethoxine solution, improves treatment outcomes, reduced wound healing time to 16 ± 1.05 days in patients of the main group against 21 ± 1.2 in comparison group, and excludes the possibility of mesh explantation in the main group against 14.3 % in the comparison group.

Infinite Energy Cavitating Solutions: A Variational Approach

Infinite Energy Cavitating Solutions: A Variational Approach

Dynamics of cellular factors of innate immunity and antioxidant protection in the patients with chronic recurrent vulvovaginal candidosis upon exposure to cavitated physiological solution

Dysfunction of colonization resistance factors at the mucous membranes of genitourinary system during adhesion of Candida fungi is a common pathogenic situation leading to impairment of the mucous membrane regeneration, unsuccessful attempts at in vitro fertilization (IVF), increased risk of complications during gestation. The aim of present study was to substantiate the opportunity of complex therapy for chronic vulvovaginal candidiasis using cavitated saline and usage suppositories with alpha-2b human recombinant interferon a (Viferon LLC, Russia). The study involved 90 women at the age of25.45±7.16 years, with clinically and laboratory confirmed recurrencies of chronic vulvovaginal candidiasis observed, on average, 5.55±0.45 times. Group 1 consisted of 30 women with C. albicans infection of urogenital tract, at the mean age of 27.11±1.52 years, who received therapy with fluconazole (150 mg once every 7 days). Group 2 consisted of 30 women with C. albicans infection of mucous membranes, mean age 27.31±1.99 years, treated with Fluconazole (150 mg 1 time in 7 days, and 5-min. irrigation of vagina with ultrasonicated saline solution, 7 days; Low-intensity ultrasound exposure was performed using the Fotek AK100-25 hardware complex, ultrasonic vibration frequency of 25 kHz (Yekaterinburg, Russia). Group 3 consisted of 30 women whose treatment included Fluconazole (150 mg once every 6 days), irrigation of mucous membranes with ultrasonicated cavitated solution and subsequent administration of suppositories containing Viferon® 500,000 IU (1 suppository daily for 7 days). Biochemical studies included determination of isopropanol- and heptane-soluble primary, secondary end products of lipid peroxidation. Activity of the antioxidant system was studied by determination of superoxide dismutase, glutathione peroxidase, ceruloplasmin, vitamin C. Qualitative and quantitative characteristics of neutrophilic granulocytes from vaginal secretions were evaluated by testing phagocytic activity, reduction of nitroblue tetrazolium compound to diformazan. The studies of IL-8, TNFα, IL-2, and IL-10 cytokines were carried out in cell-free supernates of vaginal secretions by ELISA test systems (LLC “Vector Best”, Novosibirsk). Results: upon therapeutic exposure to low-frequency ultrasonic cavitation combined with antioxidant drug, we have observed a decreased local concentration of pro-inflammatory cytokines, the balance of lipid peroxidationantioxidant defense system was restored, and functional metabolic status of the phagocytes in vaginal secretions was normalized.

Analytical study of cavitation in elastic solids with affinely varied mechanical property

ABSTRACTA tiny spherical cavity will expand unboundedly in a homogenous incompressible neo-Hookean solid when the applied hydrostatic tension reaches five times of the shear modulus of the solid. Such phenomenon is usually referred as cavitation in a soft solid. In the previous studies, the soft solid is often assumed to have homogeneous mechanical properties. In this paper, the effects of inhomogeneity have been investigated by assuming the shear modulus in the solid varies affinely with the radial coordinate. A bifurcation problem is considered for a graded neo-Hookean solid subjected to uniform hydrostatic tension on the external boundary. We find that the cavitation solution with a traction-free internal cavity can be analytically expressed using hypergeometric function. For large hydrostatic tension, the equilibrium configuration can bifurcate from the trivial solution (no cavity) to the cavitation solution (cavity occurs). Both the trivial solution and cavitation solution can be stable and unstable determined by minima of their potential energy. When the external hydrostatic tension is greater than a critical value, the internal cavity can expand both continuously or discontinuously inside the solid. We hope the results obtained in this article will be helpful to understand the cavitation phenomenon in complex soft materials.

An Assessment of Computational Fluid Dynamics Cavitation Models Using Bubble Growth Theory and Bubble Transport Modeling

This effort investigates advancing cavitation modeling relevant to computational fluid dynamics (CFD) through two strategies. The first aims to reformulate the cavitation models and the second explores adding liquid–vapor slippage effects. The first aspect of the paper revisits cavitation model formulations with respect to the Rayleigh–Plesset equation (RPE). The present approach reformulates the cavitation model using analytic solutions to the RPE. The benefit of this reformulation is displayed by maintaining model sensitivities similar to RPE, whereas the standard models fail these tests. In addition, the model approach is extended beyond standard homogeneous models, to a two-fluid modeling framework that explicitly models the slippage between cavitation bubbles and the liquid. The results indicate a significant impact of slip on the predicted cavitation solution, suggesting that the inclusion of such modeling can potentially improve CFD cavitation models. Overall, the results of this effort point to various aspects that may be considered in future CFD-modeling efforts with the goal of improving the model accuracy and reducing computational time.

Fourier-Chebyshev spectral method for cavitation computation in nonlinear elasticity

A Fourier-Chebyshev spectral method is proposed in this paper for solving the cavitation problem in nonlinear elasticity. The interpolation error for the cavitation solution is analyzed, the elastic energy error estimate for the discrete cavitation solution is obtained, and the convergence of the method is proved. An algorithm combined a gradient type method with a damped quasi-Newton method is applied to solve the discretized nonlinear equilibrium equations. Numerical experiments show that the Fourier-Chebyshev spectral method is efficient and capable of producing accurate numerical cavitation solutions.

Combination treatment using cavitated Panavir solution in patients with HPV-associated cervical intraepithelial neoplasia

Combination treatment using cavitated Panavir solution in patients with HPV-associated cervical intraepithelial neoplasia

Tissue and molecular effects of the cavitated solution in the endometrial receptivity rehabilitation of patients with the uterine infertility

Tissue and molecular effects of the cavitated solution in the endometrial receptivity rehabilitation of patients with the uterine infertility

Влияние кавитированного низкочастотным ультразвуком раствора хлоргексидина на количественный и видовой состав лактофлоры влагалища

Влияние кавитированного низкочастотным ультразвуком раствора хлоргексидина на количественный и видовой состав лактофлоры влагалища

Prediction of cryogenic cavitation around hydrofoil by an extensional Schnerr-Sauer cavitation model

Developing a robust computational strategy to address the rich physics characteristic involved in the thermodynamic effects on the cryogenic cavitation remains a challenging problem. The objective of this present study is to model the numerical methodology to simulate the cryogenic cavitation by implanting the thermodynamic effects to the Schnerr-Sauer cavitation model, and coupling the energy equation considered the latent heat. For this purpose, cavitating flows are investigated over a three dimensional hydrofoil in liquid hydrogen and nitrogen. Experimental measurements of pressure and temperature are utilized to validate the extensional Schnerr-Sauer cavitation model. Specifically, the further analysis of the cavitation solution with respect to the thermodynamic term is conducted. The results show that the extensional Schnerr-Sauer cavitation model predicts better accuracy to the quasi-steady cavitation over hydrofoil in the two cryogenic fluids.

Extension of the Schnerr–Sauer model for cryogenic cavitation

The cavitation dynamics of cryogenic fluids are substantially impacted by the thermodynamic effects since these fluids are generally operated close to the critical point and the vapor pressure assumes strong dependence on the temperature. Developing a robust numerical methodology to model the rich physics involved in this phenomenon remains a challenging problem. This paper tries to develop an effective computational strategy to simulate cryogenic cavitation by implementing the “Schnerr–Sauer cavitation model”, coupled with the energy equation. Numerical simulations of cavitation are presented for flows over a two dimensional (2-D) hydrofoil and an axisymmetric ogive. Predicted temperature and pressure depressions within the cavity are compared with measurements by Hord et al. in NASA for liquid hydrogen and nitrogen. Specifically, the global sensibility of the cavitation solution with respect to bubble number density is investigated in detail. The Schnerr–Sauer cavitation model with corrected nuclei density provides solutions with comparable accuracy to the quasi-steady sheet cavitation in cryogenic fluids for the two geometries.

Singular Limiting Induced from Continuum Solutions and the Problem of Dynamic Cavitation

In the works of Pericak-Spector and Spector (Arch Rational Mech Anal. 101:293–317, 1988, Proc. Royal Soc. Edinburgh Sect A 127:837–857, 1997) a class of self-similar solutions are constructed for the equations of radial isotropic elastodynamics that describe cavitating solutions. Cavitating solutions decrease the total mechanical energy and provide a striking example of non-uniqueness of entropy weak solutions (for polyconvex energies) due to point-singularities at the cavity. To resolve this paradox, we introduce the concept of singular limiting induced from continuum solution (or slic-solution), according to which a discontinuous motion is a slic-solution if its averages form a family of smooth approximate solutions to the problem. It turns out that there is an energetic cost for creating the cavity, which is captured by the notion of slic-solution but neglected by the usual entropic weak solutions. Once this cost is accounted for, the total mechanical energy of the cavitating solution is in fact larger than that of the homogeneously deformed state. We also apply the notion of slic-solutions to a one-dimensional example describing the onset of fracture, and to gas dynamics in Langrangean coordinates with Riemann data inducing vacuum in the wave fan.

Energy Minimising Properties of the Radial Cavitation Solution in Incompressible Nonlinear Elasticity

Consider an incompressible, hyperelastic material occupying the unit ball B⊂ℝn in its reference state. Suppose that the deformation u:B→ℝn is specified on the boundary by $$\mathbf{u}({\mathbf{x}})=\lambda{\mathbf{x}}\quad\mbox{for}\ {\mathbf{x}}\in \partial B,$$ where λ>1 is a given constant.In this paper, isoperimetric arguments are used to prove that the radial deformation, producing a spherical cavity, is the energy minimiser in a general class of isochoric mappings that are discontinuous at the centre of the ball and produce a (possibly non-symmetric) cavity in the deformed body. This result has implications for the study of cavitation in certain polymers.

Computational fluid dynamic study on cavitation in liquid nitrogen

Cavitation is the formation of vapor bubbles within a liquid where flow dynamics cause the local static pressure to drop below the vapor pressure. This paper presents the steady computational fluid dynamic (CFD) results of cavitation in liquid nitrogen flow through hydrofoils and ogives with so-called “full cavitation model”. The model is reexamined to assess the performance prediction from the standpoint of cryogenic fluids with the assumption of thermal equilibrium between vapor phase and liquid phase. The fluid thermodynamic properties are specified along the saturation line using the “Gaspak 3.2” databank. The thermal effects and accompanying property variations due to phase change are modeled rigorously. The thermodynamic cavitation framework is validated against experimental data of NASA hydrofoil and ogive. The global sensibility of the cavitation solution with respect to the cavitation model coefficients and the free-stream velocity is investigated in detail and the choking phenomenon is reported with high Mach number. The full cavitation model with the default coefficients is applicable for cavitation prediction in liquid nitrogen, taking into account of the thermodynamic effects.

Qualitative study of cavitated bifurcation for a class of incompressible generalized neo-Hookean spheres

The problem of spherical cavitated bifurcation was examined for a class of incompressible generalized neo-Hookean materials, in which the materials may be viewed as the homogeneous incompressible isotropic neo-Hookean material with radial perturbations. The condition of void nucleation for this problem was obtained. In contrast to the situation for a homogeneous isotropic neo-Hookean sphere, it is shown that not only there exists a secondary turning bifurcation point on the cavitated bifurcation solution which bifurcates locally to the left from trivial solution, and also the critical load is smaller than that for the material with no perturbations, as the parameters belong to some regions. It is proved that the cavitated bifurcation equation is equivalent to a class of normal forms with single-sided constraints near the critical point by using singularity theory. The stability of solutions and the actual stable equilibrium state were discussed respectively by using the minimal potential energy principle.

Void formation and growth for a class of compressible hyper-elastic sphere

In this paper, the strain energy function proposed by Shang and Cheng was generalized by introducing a nonlinear term. Void formation and growth in the interior of a sphere composed of compressible hyper-elastic material, subjected to a prescribed uniform displacement, was examined. A parametric cavitated bifurcation solution for the radial deformed function was obtained. Stability of the solution of the cavitated bifurcation equation was discussed. With the appearance of a cavity, an interesting feature of the radial deformation near the deformed cavity wall is the transition from extension to compression.

A Theoretical Analysis of Alternate Blade Cavitation in Inducers

An analysis of alternate blade cavitation on flat plate cascade is made using a singularity method based on a closed cavity model. In the steady flow analysis, it was found that two kinds of steady cavitation patterns exist. One is equal length cavitation in which the cavity lengths of all blades are the same. The other is alternate blade cavitation in which the cavity length changes alternately from blade to blade. Although the present model fails to predict the range of cavitation number where alternate blade cavitation occurs, it predicts alternate blade cavitation fairly well in terms of cavity length. A parameter study shows that the development of alternate blade cavitation is quite different depending on the solidity of cascade. The stability of equal length and alternate blade cavitation is then examined allowing the cavity length freely to change. It was found that alternate blade cavitation is stable for the cascades with larger solidity and unstable for the cascades with smaller solidity. The equal length cavitation is stable in both cases only in the region of cavitation number larger than that where the alternate blade cavitation solution separates from the equal length cavitation. [S0098-2202(00)01301-8]

A Stability Analysis of Alternate Blade Cavitation in Inducers.

The stability of alternate blade cavitation in flat plate cascades was examined by a linear analysis with a singularity method based on closed cavity model allowing the cavity length change. It was found that alternate blade cavitation was stable for the cascades with larger solidity and unstable for the cascades with smaller solidity. The equal length cavitation is stable only in the region of cavitation number larger than that where the alternate blade cavitation solution starts to separate from the equal length cavitation. This result suggests that the alternate blade cavitation could exist only for the cascades with higher solidity.

The Numerical Computation of Singular Minimizers in Two-Dimensional Elasticity

In this paper we use a spectral-collocation method for the computation of singular minimizers in two-dimensional elasticity. In particular we are interested in computing cavitating solutions (those that open a hole at the center) and determining whether or not they are globally stable in the energy sense. We describe the spectral collocation method which is used in conjunction with a Richardson extrapolation iteration and discuss various aspects related to the convergence of the method. We obtain a variety of results for certain ranges of parameters that show how the size of the cavitation depends on these parameters.