Leaf surface characteristics affect the deposition and distribution of droplets in rice (Oryza sativa L.)

We studied the effects of leaf surface characteristics on canopy droplet behaviour using two rice cultivars with similar leaf shapes but significantly different leaf surface characteristics: Jia58 (glabrous rice; smooth leaf surface and no burrs) and Yongyou12 (hairy-leaved rice; rough leaf surface covered with burrs). The plants were subjected to spray tests with different spray pressures and nozzle apertures. The results showed that the deposition amount per unit leaf area was significantly higher in the Yongyou12 canopy than in the Jia58 canopy. The diameter, volume median diameter, number median diameter, and coverage of droplets were significantly higher in Yongyou12 than in Jia58, while the coverage density of droplets was significantly lower. The proportion of small droplets of Jia58 is higher than that of Yongyou12. Thus, a larger amount of large-sized droplets could retain on the leaf surface of hairy-leaved rice, and a larger number of small-sized droplets were retained on the leaf surface of glabrous rice. Smaller pressure and larger flow nozzle were conducive to the retention of the Jia58, while Yongyou12 required larger pressure and larger flow nozzles. Ultrastructural analyses revealed that the leaf surface of glabrous rice had no trichomes and more wax than hairy-leaved rice, and the critical surface tension was lower, resulting in the retention of mainly small droplets on its leaf surface and a lower deposition amount. Therefore, in order to increase the deposition of pesticide droplets on the leaf surface in production, glabrous rice should choose nozzles with smaller spray pressure and large flow rate.

Biologically Compatible Lead-Free Piezoelectric Composite for Acoustophoresis Based Particle Manipulation Techniques

This research paper is concentrated on the design of biologically compatible lead-free piezoelectric composites which may eventually replace traditional lead zirconium titanate (PZT) in micromechanical fluidics, the predominantly used ferroelectric material today. Thus, a lead-free barium–calcium zirconate titanate (BCZT) composite was synthesized, its crystalline structure and size, surface morphology, chemical, and piezoelectric properties were analyzed, together with the investigations done in variation of composite thin film thickness and its effect on the element properties. Four elements with different thicknesses of BCZT layers were fabricated and investigated in order to design a functional acoustophoresis micromechanical fluidic element, based on bulk acoustic generation for particle control technologies. Main methods used in this research were as follows: FTIR and XRD for evaluation of chemical and phase composition; SEM—for surface morphology; wettability measurements were used for surface free energy evaluation; a laser triangular sensing system—for evaluation of piezoelectric properties. XRD results allowed calculating the average crystallite size, which was 65.68 Å3 confirming the formation of BCZT nanoparticles. SEM micrographs results showed that BCZT thin films have some porosities on the surface with grain size ranging from 0.2 to 7.2 µm. Measurements of wettability showed that thin film surfaces are partially wetting and hydrophilic, with high degree of wettability and strong solid/liquid interactions for liquids. The critical surface tension was calculated in the range from 20.05 to 27.20 mN/m. Finally, investigations of piezoelectric properties showed significant results of lead-free piezoelectric composite, i.e., under 5 N force impulse thin films generated from 76 mV up to 782 mV voltages. Moreover, an experimental analysis showed that a designed lead-free BCZT element creates bulk acoustic waves and allows manipulating bio particles in this fluidic system.

Effectiveness Evaluation Criteria of Using Fine Powders of Secondary Concrete as a Component of Composite Binder

The paper considers the possibility of using energy criteria (surface activity, free surface energy) to quantify the efficiency of a highly dispersed system consisting of fine particles of secondary concrete as a component of composite binder of the hydration type of hardening. Using the G.A. Zisman method, the value of the critical surface tension was determined for secondary concrete fractions with different degrees of dispersion, which gives an idea of the free surface energy of a surface area unit. Based on the experimental data for determining the specific surface area and critical surface tension, the free surface energy and surface activity of the studied concrete powder were calculated, which can serve as criteria for quantitative energy characteristics of raw materials for the production of composite binders. Calorimetric studies related to measurements of the thermal effects of the hydration reaction of highly dispersed samples of secondary concrete have shown that this process is exothermic, the enthalpy of hydration of which is comparable to a similar parameter for cement. It was experimentally shown that fine powders of secondary concrete are effective as components of a composite binder, but they need to be pre-activated to optimal parameters, one of which is surface activity. In addition, the symbasis of changes in surface activity, the specific heat of the hydration reaction of highly dispersed concrete fractions and the compressive strength of fine-grained concrete samples made by using a composite binder containing a highly dispersed fraction of secondary concrete was established.

Immediate modified prostodontic rehab for tumor of the maxilla: case report

Introduction. Timely maxillofacial orthopedic care is aimed at leveling the message of the oral cavity with the nasal cavity and its paranasal sinuses, orbit, helps to improve swallowing, speech, breathing and salivation. The objective of this work is to demonstrate the possibility of application of a polymethyl methacrylate prosthesis with a superhydrophobic modified surface directly on the operating table, as well as to demonstrate the possibility of using in the shortest postoperative period. Materials and methods. Patient Z., 28 years old, clinical diagnosis: chondrosarcoma of the upper jaw on the right, Т2N0M0, stage 2. A resection of the upper jaw was proposed with simultaneous reconstructive treatment and the application of a dental resection forming denture of the upper jaw. To form a hydrophobic surface, the prosthesis was modified with a high-frequency plasma of sulfur hexafluorides. The study of the quantitative and qualitative composition of microflora on the surface of the resection forming prosthesis was carried out after transportation of the prosthesis from the dental laboratory, after processing of high-frequency plasma of sulfur hexafluoride and before applying the resection forming prosthesis, 3, 7 days after the prosthesis was applied. Results. After modification of sulfur hexafluoride in the medium, the contact angle of contact with distilled water increased, the critical surface tension decreased compared to the initial one, and the hydrophobic properties were increased. Conditionally pathogenic microflora in a diagnostically significant amount was cultivated from the surface of the resection forming prosthesis obtained from the dental laboratory. Bacterial seeding after modification in the plasma of sulfur hexafluoride showed the absence of microflora strains; a slight increase in opportunistic microflora was obtained on days 3 and 7 after application of the prosthesis. In the immediate postoperative period (3 days), the patient complained of pain and discomfort associated with the surgical stage. Conclusions. The presented clinical case indicate that the superhydrophobic surface modified by sulfur hexafluoride contributes to a more stable healing of the postoperative defect.

Roughness and wettability of aligner materials

Objective: The characterisation of surface roughness and energy of contemporary thermoplastic materials used in manufacturing of orthodontic aligners. Design: In vitro, laboratory study. Materials and methods: Four commercially available thermoplastic materials were selected (CA-medium/CAM, Essix-copopyester/COP, Duran/DUR and Erkodur/ERK). Five disks from each, as received, material were tested and subjected to: (1) reflected light microscopy; (2) optical profilometry for the estimation of Sa, Sz, Sq, Sdr, Sc, Sv surface roughness parameters (n = 5); and (3) contact angle measurements with a Zisman series of liquids for the estimation of critical surface tension (γC), total work of adhesion (WA), as well as the work of adhesion due to polar (WP) and dispersion (WD) components employing the Zisman method (n = 5/liquid). Thermoformed disks were prepared against a dental stone model and the roughness parameters were calculated again Statistical analysis was performed by one-way ANOVA/ Tukey multiple comparison test and t-test (a = 0.05). Results: Microscopic and profilometric analyses revealed a smooth surface texture in the as-received materials, but a very rough texture after thermoforming, with insignificant differences within each state. Significant differences in the as-received state were found in the surface energy parameters; CAM showed the lowest γC and the highest WA, WP, WD, whereas ERK with the highest γC demonstrated lower WA. COP and DUR were ranked in an intermediate group regarding γC, with a statistically significant difference in WA between them, mainly attributed to the lower WP of the former. Conclusion: Given the differences in surface energy parameters and the lack of roughness differences within the as received or thermoformed groups, it may be concluded that variations in the plaque retaining capacity are anticipated, determined by γC, WA and the WP, WD components.

Durability of Coatings Based on Sol Silicate Paint

The results of the study provide information on the resistance of coatings based on the solof silicate paint in the process of freezing and thawing. It was found, that coatings based on sol silicatepaints are characterized by a higher resistance compared of silicate coatings. It is shown, that thecoatings withstood 50 cycles of alternate freezing and thawing. The surface energy of the coatingswas calculated using the critical surface tension of the fluid at the interface with the solid. Thedispersion contribution in the intermolecular interaction between the particles of the coatings wasestimated. The values of the surface tension of the coatings and the values of the dispersioncomponent of the surface energy of the coatings — the complex Hamaker constant — are calculated.It was revealed, that after testing a decrease in the values of the Hamaker constant is observed. It wasestablished, that after testing for frost resistance, the values of the Hamaker constant for coatingsbased on sol of silicate paint are higher compared to coatings based on silicate paint.