Computer-Guided Navigation System Efficiency Evaluation Using Surgical Instruments for Spinal Fusion.

Background: Navigation surgical systems have been widely used in spinal fusion to ensure accuracy and safety during pedicle screw insertion.

Methods: The research was performed under laboratory conditions, using stereotactic navigation, surgical instruments for spinal fusion, development of additional devices and software. During the experiments, all stages of the computed tomography-guided navigation system use were performed-preoperative preparation of patient data and planning to provide visual control of the navigation of surgical instruments during the insertion of screws.

Mechanical properties variation of samples fabricated by fused deposition additive manufacturing as a function of filler percentage and structure for different plastics.

One of the key factors in manufacturing products by fused deposition molding (FDM) or layer-by-layer printing technology is the material intensity of the product. The task of reducing the amount of material required to manufacture a product without significant loss of mechanical properties is one of the most practically important technological tasks. Material saving in FDM printing of products allows to reduce financial costs and increase the speed of manufacturing of the final product without reducing (or not significantly reducing) the quality properties of the product.

Acoustic Features of the Impact of Laser Pulses on Metal-Ceramic Carbide Alloy Surface.

Technologies associated with using concentrated energy flows are increasingly used in industry due to the need to manufacture products made of hard alloys and other difficult-to-process materials. This work is devoted to expanding knowledge about the processes accompanying the impact of laser pulses on material surfaces. The features of these processes are reflected in the acoustic emission signals, the parameters of which were used as a tool for understanding the accompanying phenomena.

A zirconia/tantalum biocermet: and evaluation for biomedical implant applications.

A biocermet made of zirconia/20 vol% tantalum (3Y-TZP/Ta) is a new composite with exceptional capabilities due to a combination of properties that are rarely achieved in conventional materials (high strength and toughness, cyclic fatigue resistance and flaw tolerance, wear resistance, corrosion resistance, electrical conductivity, ). In this study, for the first time, the biomedical performance of a 3Y-TZP/Ta biocermet was evaluated in detail. Its biocompatibility was assessed using mesenchymal stem cell culture.

[Determination of the presence of an antibiotic in implant-bone biopsy specimens by Raman spectroscopy in experiment].

The Aim Of The Study: Was to determine the presence of an amoxicillin-based antibiotic in bone implant biopsies by Raman spectroscopy in an experiment.

Materials And Methods: Experimental animals (=10, a miniature pig of the Svetlogorsk breed) were divided into 2 groups of 5 animals. Groups 1 and 2 were injected with amoxicillin 2 ml per 20 kg of body weight 30 minutes before dental implantation surgery, then group 2 was additionally injected with 1 ml per 20 kg of body weight for 5 days.

Materials and Methods for All-Ceramic Dental Restorations Using Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) Technologies-A Brief Review.

The materials used in dentistry for the fabrication of all-ceramic restorations have undergone great and rapid developments over the last two decades. Among the most common ceramic materials in dentistry are those based on zirconium and lithium disilicate. Due to the properties of these materials, they are in great demand in the field of dental restoration production.

3Y-TZP/Ta Biocermet as a Dental Material: An Analysis of the In Vitro Adherence of Streptococcus Oralis Biofilm and an In Vivo Pilot Study in Dogs.

The surface adhesion of bacterial cells and the in vivo biocompatibility of a new ceramic-metal composite made of zirconium dioxide and tantalum were evaluated. Within the framework of an in vitro study using the crystal violet staining and colony counting methods, a relatively similar adhesion of to the 3Y-TZP/Ta biocermet (roughness Ra = 0.12 ± 0.

Dental Implants: Modern Materials and Methods of Their Surface Modification.

The development of dental implantology is based on the detailed study of the interaction of implants with the surrounding tissues and methods of osteogenesis stimulation around implants, which has been confirmed by the increasing number of scientific publications presenting the results of studies related to both the influence of the chemical composition of dental implant material as well as the method of its surface modification on the key operational characteristics of implants. The main materials for dental implant manufacturing are Ti and its alloys, stainless steels, Zr alloys (including ceramics based on ZrO), and Ta and its alloys, as well as other materials (ceramics based on AlO, SiN, etc.).

Experimental and Statistical Analysis of the Effect of Heat Treatment on Surface Roughness and Mechanical Properties of Thin-Walled Samples Obtained by Selective Laser Melting from the Material AlSi10Mg.

Statistical analysis of mechanical properties of thin-walled samples (~500 microns) obtained by selective laser melting from AlSi10Mg material and subjected to heat treatment for 1 h at temperatures from 260 °C to 440 °C (step of aging temperature change 30 °C) has shown that the maximum strain hardening in the stretching diagram section from yield strength to tensile strength is achieved at the heat treatment temperature equal to 290 °C. At carrying out of correlation analysis, a statistically significant positive correlation between deformation corresponding to yield strength and the sum of heights of the largest protrusions and depths of the largest depressions of the surface roughness profile within the basic length of the sample (Rz) and the full height of the surface roughness profile (Rmax) was established. It was found that the reason for the correlation is the presence of cohesive states between the extreme values of the surface roughness profile that persist along the entire length of the specimen.

Influence of the Ti-TiN-(Y,Ti,Al)N Nanolayer Coating Deposition Process Parameters on Cutting Tool Oxidative Wear during Steel Turning.

Ti-TiN-(Y,Ti,Al)N coatings with a three-layer architecture (adhesive Ti layer, transition TiN layer, and wear-resistant (Y,Ti,Al)N layer) were studied. When depositing coatings, three arc current values of the yttrium cathode were used: 65, 85, and 105 A. The yttrium contents in the coatings were 30, 47, and 63 at.

Display of WEDM Quality Indicators of Heat-Resistant Alloy Processing in Acoustic Emission Parameters.

The widespread nature of heat-resistant alloys is associated with the difficulties in their mechanical machining. It forces the use of the wire electrical discharge machining to be wider. The productivity, roughness, and dimensions of the modified layer of the machined surfaces are indicators of the machining quality.

Adsorption Ability of Graphene Aerogel and Reduced Graphene Aerogel toward 2,4-D Herbicide and Salicylic Acid.

Within this work, new aerogels based on graphene oxide are proposed to adsorb salicylic acid (SA) and herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) from aqueous media. Graphene oxide aerogel (GOA) and reduced graphene oxide aerogel (rGOA) were obtained by freeze-drying processes and then studied by Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET) analysis. The influence of contact time and the concentration of the adsorbates were also assessed.

Advances in Electrical Discharge Machining of Insulating Ceramics.

There are two main ways of carrying out the electrical discharge machining of the insulating ceramics: changing the electrical and chemical properties of ceramics due to additives in producing composites/nanocomposites and changing the electrical and chemical properties in the interelectrode gap. This review summarizes and analyzes the current data on the machinability in water suspension and hydrocarbons depending on the electrical properties of the ceramic composites and assisting means such as coating and powder. There are provided the existing approaches and original methods for solving the global problem of the electrical discharge machining of insulating ceramics, suggesting further development of the existing methods since, up to now, the experimental research is non-systemic.

Plasma Electrolytic Modification of Zirconium and Its Alloys: Brief Review.

The review focuses on the surface modification of Zr and its alloys, which is necessary to expand the applications of these kinds of materials. Data on the properties of pure zirconium and its alloys are presented. Since surface engineering and the operation of the above materials are in most cases associated with the formation of oxide coatings, information on the characteristics of ZrO is given.

Investigation of Tribological Characteristics of PEO Coatings Formed on Ti6Al4V Titanium Alloy in Electrolytes with Graphene Oxide Additives.

Coatings with a thickness from ~40 to ~50 µm on Ti6Al4V titanium alloys were formed by plasma electrolytic oxidation (PEO) in a silicate-hypophosphite electrolyte with the addition of graphene oxide. The PEO treatment was carried out in the anode-cathode mode (50 Hz) at a ratio of anode and cathode currents of 1:1; their sum density was 20 A/dm, and the treatment's duration was 30 min. The effect of the graphene oxide's concentration in the electrolyte on the thickness, roughness, hardness, surface morphology, structure, composition, and tribological characteristics of the PEO coatings was studied.

Adsorption Removal of Mo(VI) from an Aqueous Solution by Alumina with the Subsequent Regeneration of the Adsorbent.

Industrial wastewater is the main source of an excessive amount of molybdenum (Mo) in natural ecosystems. It is necessary to remove Mo from wastewater before it is discharged into the environment. Molybdate ion(VI) is the most common form of Mo in natural reservoirs and industrial wastewater.

The Conditions Necessary for the Formation of Dissipative Structures in Tribo-Films on Friction Surfaces That Decrease the Wear Rate.

Tribo-films form on surfaces as a result of friction and wear. The wear rate is dependent on the frictional processes, which develop within these tribo-films. Physical-chemical processes with negative entropy production enhance reduction in the wear rate.

Assessment of experimental OpenCV tracking algorithms for ultrasound videos.

This study aims to compare the tracking algorithms provided by the OpenCV library to use on ultrasound video. Despite the widespread application of this computer vision library, few works describe the attempts to use it to track the movement of liver tumors on ultrasound video. Movements of the neoplasms caused by the patient`s breath interfere with the positioning of the instruments during the process of biopsy and radio-frequency ablation.

The Study of Radius End Mills with TiB Coating When Milling a Nickel Alloy.

Nickel alloy high-speed processing technology using ball-end mills is characterized by high contact temperature and leads to accelerated tool wear. One of the effective ways to increase its reliability and service life is to modify the surface by applying functional antifriction layers in addition to wear-resistant coatings. Diamond-like carbon is often used as the latter.

Assessment Effect of Nanometer-Sized AlO Fillers in Polylactide on Fracture Probability of Filament and 3D Printed Samples by FDM.

In this paper, a mathematical model for the description of the failure probability of filament and fused deposition modeling (FDM)-printed products is considered. The model is based on the results of tensile tests of filament samples made of polyacrylonitrile butadiene styrene (ABS), polylactide (PLA), and composite PLA filled with alumina (AlO) as well after FDM-printed products of "spatula" type. The application of probabilistic methods of fracture analysis revealed that the main contribution to the reduction of fracture probability is made by the elastic and plastic stages of the fracture curve under static loading.

Investigation of the Information Possibilities of the Parameters of Vibroacoustic Signals Accompanying the Processing of Materials by Concentrated Energy Flows.

Creating systems for monitoring technology processes based on concentrated energy flows is an urgent and challenging task for automated production. Similar processes accompany such processing technologies: intensive thermal energy transfer to the substance, heating, development of the melting and evaporation or sublimation, ionization, and expansion of the released substance. It is accompanied by structural and phase rearrangements, local changes in volumes, chemical reactions that cause perturbations of the elastic medium, and the propagation of longitudinal and transverse waves in a wide frequency range.

Evaluation of the Role of the Activating Application Method in the Cold Sintering Process of ZnO Ceramics Using Ammonium Chloride.

The influence of the method of applying the activating additive ammonium chloride and its concentration on the density and microstructure of zinc oxide ceramic obtained by cold sintering at 244 °C was investigated. The activating agent was applied by two methods: impregnation and subsequent autoclave treatment. When the powder was activated by the impregnation method, the crystal sizes remained at the initial level of 0.

Rheological Characterization and Printability of Polylactide (PLA)-Alumina (AlO) Filaments for Fused Deposition Modeling (FDM).

This article presents the study of the rheological properties and the printability of produced ceramic-polymer filaments using fused deposition method (FDM) 3D printing technology. Powder mixtures with an alumina content of 50 to 70 vol.% were fabricated by a wet processing route.

Peculiarities of γ-AlO Crystallization on the Surface of h-BN Particles.

The main goal of the present work was to synthesize a composite consisting of h-BN particles coated with a γ-AlO nanolayer. A method was proposed for applying nanocrystalline γ-AlO to h-BN particles using a sol-gel technique, which ensures the chemical homogeneity of the composite at the nano level. It has been determined that during crystallization on the h-BN surface, the proportion of spinel in alumina decreases from 40 wt.

The Phase Modulating Micro-Mover Based on the MHD/MET System in the Reference Arm of the Scanning Interferometer.

The possibility of using a magnetohydrodynamic drive (MHD) and amolecular-electronic transfer (MET) sensor as a single device for moving and precise control of the displacement of a movable mirror, which is part of a scanning interferometer, is considered. A prototype of such a device was developed and experimentally studied. A digital holographic image of the test object was obtained using an optical scheme containing a scanning interferometer with an MHD drive.