Liquid Droplet Impact Over Hydrophobic Mesh Surfaces and Assessment of Weber Number Dependent Characteristics

Impacting droplets and droplet ejection from hydrophobic mesh surfaces have interest in biomedicine, heat transfer engineering, and self-cleaning of surfaces. The rate and the size of newborn droplets can vary depending on, the droplet fluid properties, Weber number, mesh geometry, and surface wetting states. In the present study, impacting water droplets onto hydrophobic mesh surface is investigated and impact properties including, spreading, rebounding, and droplet fluid penetration and ejection rates are examined. Droplet behavior is assessed using high recording facilities and predicted in line with the experiments. The findings reveal that the critical Weber number for droplet fluid penetrating/ejecting from mesh screen mainly depends on the droplet fluid capillary length, and hydrophobic mesh size. The contact time of impacting droplet over mesh surface reduces with increasing droplet Weber number, which opposes the case observed for impacting droplets over flat hydrophobic surfaces. The restitution coefficient attains lower values for impacting droplets over mesh surfaces than that of flat surfaces. The rate and diameter of the ejected droplet from the mesh increases as droplet Weber increases. At the onset of impact, streamline curvature is formed inside droplet fluid, which creates a stagnation zone with radially varying pressure at the droplet fluid mesh interface. This reduces the ejected droplet diameter from mesh cells as mesh cells are located away from the impacting vertical axis.

ALD coated polypropylene hernia meshes for prevention of mesh-related post-surgery complications: An experimental study in animals

In this work, thermal atomic layer deposition (ALD) was used to synthesize vanadium (V)-doped TiO2 thin nanofilm on polypropylene (PP) hernia meshes. Multiple layers of (Al2O3+TiVOx) nano-films were coated on the PP hernia mesh surface to provide a layer with a total thickness of 38 nm to improve its antibacterial properties, thereby, prevent mesh-related post-surgery complications. Highly conformal V-doped TiO2 nanofilm were deposited on PP mesh at a temperature of 85 °C. Rats and rabbits have been used to evaluate the tissue reaction on coated PP hernia meshes and biomechanical testing of the healed tissue. 5 rabbits and 10 rats have been implanted with ALD coated and uncoated (control) PP meshes into the back of rats and abdominal wall of rabbits. Histology of the mesh-adjacent tissues and electron microscopy of the explanted mesh surface were performed to characterize host tissue response to the implanted PP meshes. The effect of V-doped TiO2 coating on a living organism and fibroblast functions and bacterial activities were studied. The present results indicated that ALD coating improves adhesion properties and exhibited enhanced antibacterial activity compared to uncoated PP mesh. It was shown that V-doped TiO2 coatings were highly effective in inhibiting S. aureus and E. coli adhesion and exhibited excellent antibacterial activity. We found that V-doping of TiO2, unlike bare TiO2, allows generated and further procured strong redox reactions which effectively kills bacteria under visible light. We have reported comparative analysis of the use of undoped (bare) TiO2 and V-doped TiO2 as a coating for PP meshes and their action in biological environment and preventing biofilms formation compared with uncoated PP meshes. The PP meshes coated with V-doped TiO2 showed significantly lower shrinkage rates compared with an identical PP mesh without a coating. We have shown that ALD coatings provide non-adhesive and functional (antibacterial) properties.

Ultra-Precision Single-Point Diamond Turning of a Complex Sinusoidal Mesh Surface Using Machining Accuracy Active Control

Single-point diamond turning (SPDT) assisted with slow tool servo (STS) is the most commonly utilized technique in the fabrication of optical modules. However, the tool path significantly affects the quality of the machined surface. In order to realize the determined machining accuracy effectively, a tool path generation (TPG) method based on machining accuracy active control (MAAC) is presented. The relationship between tool path and machining error is studied. Corner radius compensation (CRC) and the calculation of chord error and residual error are detailed. Finally, the effectiveness of the proposed approach is verified through a machining error simulation and a cutting experiment of a complex sinusoidal mesh surface fabrication.

Essential anatomical landmarks in placement of an adequate size mesh for a successful ventral hernia repair

Safe and effective hernia repair requires a surgeon to have the appropriate knowledge necessary to learn details of the surgical technique. Long-term results of treatment, even with the use of synthetic implants, have shown that recurrences were still a significant clinical problem concerning up to every fourth patient. Therefore, it was pointed out that the mere presence of synthetic material is not a solitary circumstance sufficient for a successful repair. A key finding in recurrence prevention has been to focus surgeons' attention on the relationship between the size of the hernia orifice and the mesh surface. An optimal ratio of these values has not been established yet, however, it is considered that the mesh surface area should be at least sixteen times larger than the area of the abdominal wall defect. In cases of medium and large hernias, in order to place an extensive mesh sheet in the appropriate anatomical space of the abdominal wall, an extensive dissection needs to be performed, including several different compartments. Therefore, a surgeon undertaking a hernia repair needs to know perfectly the anatomy and function of all the myofascial structures involved. Performing an incorrect dissection of a mistaken structure may lead to catastrophic abdominal deformities. Depriving the patient of the natural support of the abdominal wall provided by the muscles may lead to total or partial destabilization of the trunk and lead to disability. In this paper a detailed description of anatomical structures and its practical use has been presented.

ANALYSIS OF FACTORS AFFECTING THE PERFORMANCE OF THE VERTICAL COTTON CLEANER

This article analyzes the process of cleaning cotton from small trash impurities and the requirements for each equipment, the influence of cotton loosening in the cotton cleaning zone and factors affecting its efficiency, studied the factors affecting the performance of a modernized cotton cleaner, where cotton moves along the pegs and mesh surface vertically and parallel.Key words:cotton, small trash impurities, peg drum, mesh surface, cleaner, zone, vibration, moisture, productivity, testing.

THE RESULTS OF PRACTICAL RESEARCH OF THE SEPARATOR IN AN EFFICIENT DESIGN THAT SEPARATES THE RAW COTTON FROM THE AIR

The article provides information on the main disadvantages of separators currently used in ginneries. The results obtained by identifying ways to overcome the above-mentioned shortcomings and introducing into the production of separators of new efficient design are also presented. The analysis of the results shows that the improved SXM inertial separator allows to preserve the natural properties of cotton by 15-20% compared to the current SX separator, as well as to provide a stable and stable average of 15 t / h. KEYWORDS: raw cotton, separator, seed, mesh surface, air flow, vacuum - valve.

A surface-based calibration approach to enable dynamic and accurate quantification of colorimetric assay systems

A mesh surface that incorporates color saturation, assay time, and standard concentration improves colorimetric assay dynamic range and accuracy.