Circular Blade Research Articles

Effect of Air Particle Abrasion and Primers on Bond Strength to 3D-Printed Crown Materials.

Two 3D-printed crown materials (Crown and Ceramic Crown) were examined to determine the best surface treatment and primers for bonding. Discs of the two materials were printed and mounted with their "intaglio" surfaces untouched. Half the specimens from each group were sandblasted with 50 µm alumina. Then, specimens were divided into four groups (n = 10): Gr1-no further treatment; Gr2-one coat of silane; Gr3-one coat of universal adhesive; Gr4-one coat of silane, then one coat of universal adhesive. Bond strength specimens were prepared with an Ultradent shear bond strength apparatus using Filtek Supreme composite. Specimens were stored for 8 weeks in 37 °C water. The specimens were debonded with a circular notched-edge blade applied at 1 mm/min, and the shear bond strength was calculated. The data were compared with a two-way ANOVA (factors: surface treatment and primer) and a Tukey post hoc analysis for both materials independently, with p < 0.01 considered meaningful. The filler content (burned ash) and resin content (FTIR) of the materials were determined. For both materials, factors surface treatment and primer were significant (p < 0.01), but their interaction was not (p = 0.43 for Crown and p = 0.34 for Ceramic Crown). Alumina air particle abrasion improved the bond strength for both materials. The Tukey post hoc analysis grouped primer treatments into the same statistically different groups for both materials: Gr1 and Gr2 < Gr3 and Gr4. The filler percentage of Crown was 32.7% and Ceramic Crown was 48.2%. Resin content was similar for both materials. The most effective method to bond to 3D-printed crowns (regardless of filler percentage) was to sandblast with 50 µm alumina and apply a layer of adhesive (with or without previous application of silane).

NUMERICAL INVESTIGATION AND NEW INTELLIGENT SYSTEM FOR PERFORMANCE IMPROVEMENT OF A RADIAL IMPULSE TURBINE FOR WAVE ENERGY CONVERSION

This study presents a numerical investigation into the influence of rotor blade geometry on the performance of oscillating water column (OWC) impulse turbines for wave energy conversion. A numerical model was developed and validated using experimental data for both circular and elliptical rotor profiles. Simulations were conducted for inhalation and exhalation modes of turbine operation, focusing on flow angles, flow coefficients, and losses coefficients in various turbine components. Results reveal significant differences in performance and flow behavior between turbines with circular and elliptical blade profiles, particularly in the inhalation mode. Circular blade profiles demonstrated superior performance and favorable flow characteristics, whereas elliptical profiles exhibited more pronounced flow separation attributed to higher curvature variation. The findings underscore the critical role of blade profile in determining turbine performance, highlighting the importance of optimizing blade design for enhanced efficiency. Building upon these results, an integration of an intelligent control system for guide vane geometric angles is proposed to ensure optimal alignment with downstream flow angles throughout the cycle. This study contributes to the understanding of turbine performance in OWC systems and provides insights for future design optimization efforts aimed at maximizing energy conversion efficiency.

Automation in Agriculture: A Robotic Approach to Weed Control for Greenhouse Cucumber Cultivation

The increasing global population has heightened the demand for efficient food production, leading to the adoption of compact cultivation methods such as greenhouses. However, weed growth within these controlled environments significantly challenges crop productivity. The application of robots can be a useful and economic choice. This study presents an innovative, purely mechanical system for weed control in greenhouses, specifically designed to operate autonomously on a monorail. The machine stops in the distance between the two main plant rows (cucumber) and its arm goes into the gap to deploy the weeds by rotating its blades. This is continued repeatedly. The cutting is by the rotational speed of the blade. Variable-speed motions of the blade were at 3500, 2500 and 1500 rpm for 3 types of moulinex, triangular, and circular blades. The movement speed of the arm was 10 and 30 rpm and the forward movement speed of the machine was 30, 40, 50, 60, 80 and 120 rpm. The results showed that different blades, blade speeds and engine speed affect significantly (p &lt;0.05) the percentage of weeds being cut. Although the interactions of these factors have no significant effect on percentage; the average percentages by the blades have significant differences. Although the interactions between these factors were not statistically significant, the comparison of means revealed that at lower blade speeds, the blade type had a pronounced effect on weed-cutting efficiency. As blade speed increased, differences in blade performance diminished. The most effective combination was achieved using Moulinex blades at 3500 rpm with a 10-rpm arm speed, resulting in the highest percentage of weeds cut. These findings suggest that optimizing blade type and speed can significantly enhance the mechanical weed control efficiency in greenhouse environments.

A Step beyond Reliability in the Industry 4.0 Era: Operator-Leveraged Manufacturing

Avoiding downtime is one of the major concerns of manufacturing industries. In the era of connected industry, acquiring data has become cheaper than ever; however, turning that data into actionable insights for operators is not always straightforward. In this work, we present a manufacturing scenario involving a circular blade rubber cutting machine, where the goal is to minimize downtime. Historical cutting data are available, and the aim is to provide the machine operators with an intuitive tool that helps them reduce this downtime. This work demonstrates how, in an Industry 4.0 environment, data can be leveraged to minimize downtime. To achieve this, different survival model approaches are compared, a Health Index (HI) is developed, and the model deployment is analysed, highlighting the importance of understanding the model as a dynamic system in which the operator plays a key role.

Design of Vibration and Noise Reduction for Ultra-Thin Cemented Carbide Circular Saw Blades in Woodworking Based on Multi-Objective Optimization

Cemented carbide circular saw blades are widely used for wood cutting, but they often suffer from vibration and noise issues. This study presents a multi-objective optimization method that integrates ANSYS and MATLAB to optimize the design of noise reduction slots in circular saw blades. A mathematical model was developed to correlate the emitted sound power with the overall vibration intensity. A multi-objective optimization model was then formulated to map the slot shape parameters to the deformation, equivalent stress, and vibration intensity during sawing. The ABAQUS thermal–mechanical coupling analysis was used to determine the sawing force and temperature field. The NSGA-II algorithm was applied on the ANSYS–MATLAB platform to iteratively compute slot shape parameters and conduct optimization searches for a globally optimal solution. Circular saw blades were fabricated based on the optimization results, and experimental results showed a significant reduction in sawing noise by 2.4 dB to 3.0 dB on average. The noise reduction effect within the specified frequency range closely agreed with the simulation results, validating the method’s efficiency. This study provides a feasible and cost-effective solution to the multi-objective optimization design problem of noise reduction slots for circular saw blades.

Analyzing the effect of hydrodynamic damping on the wake behavior in circular blade cascades: numerical study on a global mode

Abstract In this study, a numerical investigation has been performed to extract and compare the hydrodynamic damping of a non-rotating system of eight planar hydrofoils, arranged in a radial configuration, with the related wake behaviour downstream the structure. A modal acoustic analysis has been performed on the structure in order to extract the global modes corresponding to Nodal Diameter 0. Using the deformation related to the global mode, the hydrodynamic damping has been extracted for different velocities, ranging from 2 to 14 m/s, by analyzing the work done on the structure from the fluid, following the so-called “flutter” method developed by ANSYS®. The related wake behaviour has been analyzed for each specific velocity and hydrodynamic damping conditions. This numerical study has been performed in ANSYS Mechanical® and CFX®. The results for the present geometry suggest that the primary factor governing vortex shedding frequency is the motion of the body itself, in the present case locked to the excitation frequency of the global structural mode (ND0). The study identifies a lock-in region around 10 m/s, consistent with empirical formulas. After the region of lock-in, the fluctuations of velocity and pressure values tend to converge, indicating a stabilization of the wake dynamics. The observed hydrodynamic damping trend exhibits a linear pattern preceding the lock-in region, succeeded by a steep rise thereafter. This pattern aligns with established literature, affirming its consistency with prior research findings. Overall, this numerical approach offers valuable insights into wake behavior and hydrodynamic damping value serving as a promising tool for preliminary estimation and analysis of oscillating systems in water flowing environments. Its low computational complexity and rapid completion time make it a viable alternative to more complex FSI simulations, facilitating comprehensive exploration of multiple flow scenarios within a reasonable time frame of weeks.

Study on the Temperature Distribution and Natural Frequency of a Circular Saw Blade during Three Types of Wood Sawing Processes

Abstract The stability of a circular saw blade during the cutting process affects the knife life and the material utilization rate. In this article, continuous sawing experiments were carried out on medium-density fiberboard, Pterocarpus soyauxii board, and reconstituted bamboo lumber board. The temperature distribution of the saw blade surface was measured. The natural frequency of the saw blade under thermal stress was analyzed by the finite element method. The results show that the material density is positively correlated with the edge temperature of the saw blade. Greater temperature differences within the saw blade lead to worsening dynamic stability. When cutting the reconstituted bamboo lumber board, the saw blade will suddenly lose stability, and the surface temperature will rise rapidly, which greatly shortens the life of the saw blade.

Experimental Studies of Pressure Pulsations in Draft Tube Diffuser of Pump-Turbine Models for Heads up to 200 m

Introduction. Increasing the share of balancing capacities to cover daily peaks in electricity consumption is one of the top priorities of the postwar development of Ukraine’s energy sector.Problem Statement. Today, power plant hydraulic turbines need both to increase effi ciency and to expand their operating range. For example, the new hydraulic units of the Dniester PSP shall operate in turbine mode in the range of 40—100% of rated capacity, while the four previous units operate in the range of 70—100%. This requirement can be met by increasing efficiency and reducing pulsations at low power output.Purpose. Based on studying the infl uence of blade spatial shape of a Francis pump-turbine runners on fl ow parthydrodynamics, to identify the patterns of pressure fluctuations distribution in draft tube diff user of the hydraulic unit model.Materials and Methods. Three options of models (the original and two modifi ed ones) have been studied onthe IMEP ECS-30 hydrodynamic test stand. The runner blades are made of PLA plastic by 3D printing. Pressurepulsations are measured by sensors at two points of draft tube diff user at a distance of 0.2 and 1.5 runner diameters from the runner bottom shroud.Results. Three modifi cations of the pump-turbine runner for heads up to 200 m have been designed and experimentally studied with the use of circumferential lean that diff er from the original version only in relative position of blade profiles. The analysis of obtained energy and pulsation characteristics of the models in turbine modehas shown that the model with the runner having a negative circular blade lean has the best performance. Conclusions. The determined influence of spatial shape of the runner blades on the energy and pulsation characteristics of the Francis pump-turbine model for heads up to 200 m has made it possible to increase its efficiency and to reduce the level of pressure fluctuations in the flow part.

Cutting with Circular Saw of Traversal-Structured Panels Obtained from Spruce (Picea abies L.) Branches

Finding new wood resources is a permanent challenge nowadays, especially due to the fact that there is a crisis of these resources through the continuous degradation of forest areas that can be exploited. In this general context, the use of spruce (Picea abies L.) branches to create panels with a transverse texture becomes the main purpose of this research. Going beyond the current stage of research in the field, this research highlights the particularities of cutting panels with a transverse texture made from spruce branches, especially due to the cutting direction compared to the wood grain. In addition to the activities of collecting and sorting the branches, processing and joining, in order to obtain dimensionally stable panels, the workability of these panels with a transverse texture represents a new challenge in this field. The work methodology was based on the effective measurement of the cutting and advance power during cutting with a circular blade. The obtained results referred to the comparison of 10 working regimes from the point of view of the electrical power consumed, according to the two main parameters taken into account, which are the rotational speed of the circular blade and the advance speed. The final conclusion of the work highlighted the fact that the processing of panels with a transverse structure requires specific work regimes, namely an optimal regime of electric consumption of 2.2 kW, at a cutting speed of 79.2 m/s and an advance speed of 3.7 m/min.

Investigation of Furrow Formation by Rotary Tillage Tools with an Active Drive

Power driven rotary tillage tools are widely used in agriculture. However, the process of furrow formation by these tillage tools remains insufficiently studied. (Research purpose) To study the process of furrow formation by the actuating elements of rotary working bodies with an active drive. (Materials and methods) The experiments were carried out on a laboratory setup in a soil bin filled with sandy soil. The attack angle of the working elements ranged from 30 to 90 degrees, and the kinematic parameter varied from 0.8 to 2.2. The actuating element of the investigated rotary tillage tools was made in both circular and elliptical blade forms with the least curvature line (the major semi-axis of the ellipse). The actuating element with an elliptical blade has the ability to adjust the angle of inclination relative to the axis of rotation of the of the tillage tool. (Results and discussion) Rotary tillage tools with a circular blade form a furrow parallel to the travel direction. It has been established that an increase in the attack angle of the tillage tool from 30 to 90 degrees results in a twofold increase in the width of the furrow. The actuating element, made along the elliptical line of the blade, forms a furrow having the shape of a parallelogram when viewed from above. At a small angle of attack, this actuating element forms a short, narrow furrow deviating from the unit’s travel direction within the boundaries of the furrow width of the rotary tillage tool. (Conclusions) The results obtained make it possible to choose the parameters for the studied rotary tillage tools, which will ensure the formation of optimal furrows. This will increase the evenness of the furrow bottom and the degree of weed destruction, i.e. improved soil quality.

Native Aortic Valve Resection Using a Novel Blade-Based Device.

The aim of this study was to validate the use of a new resection device in patient candidates for surgical aortic valve replacement. We evaluated the efficacy of this new circular blade to resect the aortic valve and the efficacy to collect the debris during the resection. For this study, a single size instrument was used, with an external diameter of 22 mm, and patients were selected on the basis of the preoperative assessment of the aortic diameters. From October 2018 to June 2019, 10 patient candidates for surgical aortic valve replacement were selected to undergo native aortic valve resection using a new device, before surgical valve implantation. The mean age of the patients was 74 ± 7.6 years, and 8 of 10 were male. The mean aortic annulus diameter, measured before the procedure, was 25.7 ± 1.57 mm. The resection was complete in 9 (90%) patients. In 1 patient, due to an imprecise positioning of the device, the valve resection was partial. None of the patients showed signs or symptoms due to debris embolism. In all patients, the postoperative course was uneventful. These preliminary results show that resection of the aortic valve using a circular foldable blade is feasible. This prototype, used during conventional surgery even through a small incision, provided an efficient tool to easily resect the valve without debris release.

Hypericumliboense (Hypericaceae), a new species from Guizhou, China.

Hypericumliboense M.T.An & T.R.Wu, sp. nov. (Hypericaceae) is a newly described species found in the Maolan National Nature Reserve of Guizhou Province, where it grows in rocky habitats without soil on karst mountain tops. In this study, key morphological characters were compared between the new species and the other known Hypericum species of Hypericaceae. DNA sequences were extracted from the leaves of the new species, with nuclear gene sequences (ITS) generated to reconstruct phylogenetic trees and describe its phylogenetic position in relation to other species of Hypericum. Our results show that the proposed new species has the typical characteristics of the genus Hypericum in morphology being similar to Hypericummonogynum, but differing in its sessile and semi-clasped leaves, long elliptical to long circular leaf blades, thickly papery to thinly leathery, with entire and wavy leaf margins. The abaxial side of the leaves is covered with white powder, giving them a grey-white appearance. The main lateral veins of the leaves are 8-15-paired, and the midvein on both sides is convex. The main lateral veins and midvein branch are conspicuous, with tertiary venation forming a network on the leaf surface and appearing prominently sunken. The inflorescences are 1-3-flowered, with a large calyx and conspicuous veins. The molecular phylogenetic analysis (PP = 1.00) provided substantial evidence for the proposition of H.liboense as a new species within Hypericum. Morphological and molecular evidence is presented, corroborating the proposition of the new species, including a comprehensive account of the distinctive morphological attributes of H.liboense, along with its key distinguishing features from similar species.

Design optimization of nozzle configuration in deep sea double-jet hydraulic collector

The ocean floor harbors abundant mineral resources, making seabed ore collection technology a prominent research area for scholars worldwide in recent years. In order to further explore the ore collection characteristics of the double-jet hydraulic collector, a numerical simulation method is employed to construct a numerical model, optimize the structure of front and back jet nozzle of the collector, and analyze the effects of circular tube nozzle and blade nozzle, different diameter of circular tube nozzle and nozzle axis distance on the collection efficiency and disturbance of the collector. It is concluded that the double-jet hydraulic collector achieves optimal collection performance when the circular tube nozzle has a diameter of 14 mm and the nozzle axis distance is twice the diameter of the round tube, and higher flow rates are better for collecting nodules but also increase environmental disturbance.

Experimental Study on the Dynamic Stability of Circular Saw Blades during the Processing of Bamboo-Based Fiber Composite Panels

Bamboo-based fiber composite panel is a new type of composite material with excellent performance. When processing bamboo-based fiber composite panels, the dynamic stability of the circular saw blade affects the surface quality of the product and the life of the machinery and equipment. Sawing heat and vibration characteristics can significantly affect the dynamic stability of circular saw blades. Circular saw blade temperature and vibration characteristics are affected by the processing parameters, and the circular saw blade temperature and vibration characteristics are analyzed by changing the processing parameters. Adopting the thermoset coupling model can be used to analyze the change rule of circular saw blade temperature when sawing bamboo-based fiber composite boards, and at the same time to analyze the change rule of circular saw blade temperature, vibration speed, and vibration acceleration through the use of by CCD experiments. The regression equations for circular saw blade temperature, vibration velocity, and vibration acceleration were derived through the use of ANOVA and significance analysis. The thermoset coupling model predictions agree with the experimental results, and the density of the isotherms is progressively thinner as the temperature is conducted from the serrated region to the body of the saw. Finally, the accuracy of the regression equations for circular saw blade temperature, vibration velocity, and vibration acceleration was checked via error analysis. The temperature change regression equation has the highest fitting accuracy, with an average error of only 1.37%; the vibration velocity and vibration acceleration regression equations have poorer fitting accuracy, with an average error of 9.5% and 11.45%, respectively, but all of them have sufficient accuracy to predict the dynamic stability of circular saw blades. The results of the study can provide some guidance for the innovative design of circular saw blades.

Design of a Mini Rice Harvester for Rural and Small Scale Rice Farmers in Tropical and Developing Countries

Food insecurity, price volatility and under-employment of rice farmers in Liberia are key drivers for the development of rice farming machines locally. This project work aims to design and fabricate a simple, low-cost, efficient mini rice harvester powered by a solar panel by translating learnt concepts and principles of engineering into a physical and workable rice harvester. A circular blade cutter, DC motor, DC battery and solar cells are the main components deployed on a rod-plate setup. The solar cell taps solar irradiance from the sun and, with the help of a charge controller, recharges a 12V, 35Amp.hour battery. The battery supplies DC current to a DC motor that drives a circular blade cutter during harvesting. The fabricated harvester fulfilled all design objectives and was justifiable on overall financial cost (USD 194.00), ease of use, and ease of reproduction. The performance of the harvester, in terms of smoothness of cut and completion of cut area, was found to be near 100%. However, the harvester field efficiency performance was found to be 30.75% with an aggregated efficiency of % and a payback period of only 71 hours of operation, equivalent to 60,696 sq.m of harvested rice farm. Incessant clogged cutter's surface and harvested stem removal delays, slowdowns as the operator makes turns, switch failures and re-fix delays during field tests are the primary causes of the low field efficiency. With an improved spacing between the blade cutter and the secondary guard, the performance of the harvester is expected to improve significantly. An average noise level of 88.8 decibels was detected during the harvester's operation; advisably, hearing protection earmuffs may be necessary to safely operate the mini harvester on the dailies for 6 hours. Notwithstanding that the effect of moisture content of the rice stalks, as an input parameter, was not considered in the development of the power requirement for the rice cutter, the harvester can be optimized with minimal effort for commercialization and adopted as a Made-In-Liberia invention.

Формирование секторных полей остаточных термопластических напряжений в полотне круглой пилы

The efficiency of a stationary circular saw is determined by the performance and operational reliability of the woodcutting unit. During operation, the circular saw blade is exposed to a variety of complex loads and thermal conditions. The rigidity and stability of the saw blade determine its capacity to resist the perturbing cutting forces. The cutting compound itself is a thin disc made of steel with a hole in the middle that has a serrated cutting edge. It consists of three areas: peripheral, middle, and central. The stability of the saw blade is determined by the middle and peripheral parts. The increase in durability is achieved by plastic deformation to form the strip boundaries of the radial sections. These parts are treated by forging in both national and international practice. Normalization of loads on the blade in case of local mechanical contact with the working body is formed in the strip boundaries of the radial sections through the formation of places with plastic deformation of the metal, which rearrange the loads and place them in the radial direction. At the same time, countertension appears from the adjoining sections, leading to mutual “repulsion” of them and the creation of compressive tension that compensates for the forces of centrifugal acceleration, thermal heating of separate areas of the saw blade, external longitudinal and transverse bending tension that arise during wood processing. The combined interaction of all adjoining sections provides the tension and stability of the saw blade. The creation of the radial sections by forging has some significant disadvantages. Their elimination requires a fundamentally new approach, such as the formation of the residual stress sections in the saw blade by thermal exposure. It creates a normalized residual thermoplastic tension in the saw blade by a short-time (1–2 s) focused thermal influence on the strip boundaries of the radial sections. The results of the conducted research determined the boundaries of the sections for thermal treatment and the temperature range, which ensure the formation of normalized residual thermoplastic tension in the circular saw blade through concentrated pulsed heating of the strip edges of radial sections. For citation: Melekhov V.I., Solovev I.I. Formation of Sectoral Residual Thermoplastic Tension Fields in Circular Saw Blade. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 146–154. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-146-154

Research on the Effect of Heat Tensioning on the Dynamic Stability of Circular Saw Blades with External Scrapers

Abstract Heat tensioning was proposed and proved to be effective for improving the dynamic stability of circular saw blades with ideal disk structure by a previous scholar. With the diversification of circular saw blade structure, circular saw blades with external scrapers are widely favored by the market because of their excellent resistance to sawing thermal stress. For circular saw blades with external scrapers, the effect of heat tensioning on the dynamic stability of the blades needs to be further studied. Therefore, the heat tensioning process of circular saw blades with external scrapers was built by the finite element method. The stress field and critical rotational speed of circular saw blades with a different structure after the heat tensioning process were calculated and analyzed. The relationships between circular saw blade structure, the dynamic stability of circular saw blades, and the heat tensioning process are clarified in this article. The results show that heat tensioning is not valid for all types of circular saw blades. For circular saw blades with external scrapers, the effect of heat tensioning on improving the critical rotation speed of the blades is gradually decreased with the number of external scrapers. When circular saw blades are heat tensioned, the average tangential stress of the outer edge of the blades and the critical rotation speed of the blades are higher.

Multi-objective optimization of cross-section integrity rate and sawing power consumption in sawing Caragana korshinskii Kom. branches

Caragana korshinskii Kom. (CKK) is one of the main trees for wind and sand control in northwest China. According to its biological characteristics, flat stubble is the main measure and the critical stage of nurturing management. However, the quality of the CKK sawing surface not only affects the sprouting rate of the following year but also reflects the mechanical properties of flat stubble. To reduce the sawing power consumption of the CKK stubble device and improve the quality of sawing cross-section, this paper conducted branch sawing tests on a self-designed sawing experiment rig. Using the central composite design test method, the operating parameters of the sawing experiment rig were studied experimentally, with sawing speed (va), moving speed (v’f), and inclination angle of the circular blade (α) as the influencing factors, sawing power consumption (Y1) and cross-section integrity rate (Y2) as the objective functions, to establish a multiple mathematical regression model between them. The test results show that the influence of each factor on the sawing power consumption in the order of significance is the va, v’f, and α, and the influence of each factor on the cross-section integrity rate in the order of significance is the v’f, va, and α. The optimal combination of working parameters is va of 42 m/s, v’f of 0.3 m/s, and α of 10°, which corresponds to Y1 and Y2 of 279.73 W and 82.6% respectively. Based on the optimal combination of working parameters, the prototype was processed and field tests were conducted. The field test results showed that the stubble breaking rate and missed cutting rate of the CKK harvester are 5.5% and 4.7% respectively, and the CKK branches sprouted well in the following year after flattening the stubble, which all met the requirements of the CKK harvesting operation.

A Numerical Model for Rock Cutting with Diamond Circular Saw Blade Based on Smoothed Particle Galerkin Method

A simulation approach was utilized to investigate the mechanics of cutting rock using the diamond circular saw blade in this paper. The smoothed particle Galerkin (SPG) method was used to numerically simulate three factors, including the dynamic mechanical behavior of the circular saw blade, the damage law of the circular saw blade, and the cutting force of the saw blade. The experimental comparison indicated that the SPG approach is feasible and accurate in the analysis and simulation of the rock cutting mechanism. The rock cutting is a process of material cyclic removal. The wear parts of the saw blade are most obviously manifested at the end of the saw segments. The water groove is also readily damaged in the alternating action, which has a significant impact on the service life of the saw blade. The effects of speed, cutting depth, and feed speed on the cutting force are discussed. The results reveal that these mentioned factors are important to the quality of rock cutting.

New technologies in airway management: A review

The evolution of medical knowledge and technological growth have contributed to the development of different techniques and devices for airway management. These appear to play a role in optimizing the number of attempts and overall success, ultimately reducing the negative consequences of airway manipulation. In this literature review, we highlight the recent evidence regarding new technologies applied to airway management. Before intubation, every patient should have an individualized structured airway management plan. Technology can help with both airway evaluation and tracheal intubation. Point-of-care cervical ultrasound and artificial intelligence models with automated facial analysis have been used to predict difficult airways. Various devices can be used in airway management. This includes a robotic video endoscope that guides intubation based on real image recognition, a laryngeal mask with a non-inflatable cuff that tries to reduce local complications, video laryngeal masks that are able to confirm the correct position and facilitate intubation, Viescope™, a videolaryngoscope developed for combat medicine with a unique circular blade, a system that uses cervical transillumination for glottis identification in difficult airways and Vivasight SL™ tracheal tube, which has a high-resolution camera at its tip guaranteeing visual assurance of tube position as well as guiding bronchial blocker position. To conclude, we detailed the challenges in airway management outside the operating room as well as described suction-assisted laryngoscopy and airway decontamination technique for contaminated airways. Further research in the clinical setting is recommended to better support the use of these technologies.