Influence Of Different Angles Research Articles

Auditory perception based milling posture detection and depth control enhancement for orthopedic robots

The use of robots for bone milling is thought to improve surgical efficiency and reduce surgeon fatigue. Surgeons can use their hearing to perceive the milling state and adjust the position of surgical tools. Inspired by this, this paper proposes an automatic tool position control method based on acoustic signal feedback. Firstly, the mapping model between milling depth and sound energy was calibrated through experiments, and the influence of different angles on depth estimation accuracy was tested. Then, a network of CNN-GRU with an attention mechanism is designed to realize milling angle recognition using acoustic features as inputs. Finally, a milling depth automatic control framework with angle optimization was designed and validated through relevant experiments. The results of the experiment showed that the depth estimation error was larger when the milling angle of ball end milling tools (BMT) was within 70-90°. After adding the angle adjustment function, the milling depth accuracy in angle interval 1 (80-90°) and angle interval 2 (70°-80°) increased by about 30% and 10%, respectively.

CFD simulation analysis of air curtain applications in vulcanization machines

Abstract This study simulates the vulcanization gas generated during the processing of the vulcanizing machine. During the simulation process, the influence of different angles and flow rates of the gas curtain on its flow field is simulated. Since the rubber has to go through the vulcanization process of the vulcanizer during the manufacturing process, the original liquid rubber is turned into a viscoelastic rubber solid. During the process, toxic and high-temperature vulcanization gas will be generated due to high-temperature hot pressing. If a large amount of this gas is inhaled, it will cause harm to the human body. Therefore, this study uses the CFD software Flow Vision to simulate the opening of the vulcanizing machine, and observes the flow field with different air curtains to find the most suitable air curtain wind speed and angle. Then, make a simple model for actual experiments, using CO2 instead of sulfide gas and installing a CO2 sensor at the nose of the mannequin, using the sensor to observe whether there is excessive CO2 diffused to the mannequin to judge the air curtain. Whether the gas is successfully prevented from spreading to the position where the personnel is located, to facilitate the observation of the gas diffusion, a smoke machine and a ray generator are added so that the gas diffusion status can be observed in real-time. In the end, finding the 9 m/s flow rate and a 90° air curtain angle positioned near the machine can greatly reduce the inhalation of excessive sulfide gas by machine operators and reduce the potential harm to the human body during work.

In-plane compression characteristics of star-shaped honeycomb with asymmetric cells

A star-shaped honeycomb with asymmetric cells is proposed in this paper. The accuracy of the finite element model is verified by experiments, and the mechanical characteristics and deformation modes of the honeycomb are studied by numerical simulation. First, the energy absorption and deformation modes of a star-shaped honeycomb with asymmetric cells were studied under low-, medium- and high-velocity impacts. Second, the influence of different angles and different wall thicknesses on the energy absorption of honeycomb was studied. The results show that model 3 exhibits obvious negative Poisson's ratio characteristics under different impact velocities. As the angle increases, the energy absorption and plateau stress of mode 1 also increase. However, for mode 3, increasing θ can enhance the negative Poisson's ratio, but the specific energy absorption and plateau stress of the structure will decrease. Compared with the traditional star-shaped honeycomb, θ = 50° for mode 1, the specific energy absorption and plateau stress are increased by 21.53% and 13.32%, respectively. With increasing wall thickness, the specific energy absorption and plateau stress were significantly increased. Compared with mode 1 with t = 0.5 mm and mode 1 with t = 0.75 mm, the specific energy absorption and plateau stress increased by 50.51% and 125.56%, respectively.

Study on the influence of belt angle on tire grounding characteristics under longitudinal slip conditions

Using ABAQUS software as a tool and 225/60R18 tire as the research object, a finite element model of the tire was established and longitudinal slip simulation was conducted based on the completion of longitudinal slip and rubber material tests. By comparing the tire-pavement contact stress under longitudinal slip conditions with different angles of belt layers and the stress on the first belt steel cord, the influence of different angles of belt layers on the grounding characteristics of tires were analyzed. The results showed that under static loading conditions, the trend of tire-pavement contact stress presented a symmetrical “W” shape. Under dynamic longitudinal slip conditions, the tire-pavement contact stress curve was significantly different from the static loading simulation, with significant fluctuation and presented an irregular “W” shape, and asymmetric distortion occurred with the change of slip rate. At higher slip rates (±20%), the higher the asymmetry of the grounding imprint at the 61° and 63° belt layer angles. At the 65° belt layer angle, the ground imprint is more evenly distributed on the tread. The curve of stress variation on the belt steel cord along the path is in an “M” shape, and the stress on the belt steel cord is mainly distributed symmetrically on the tire-pavement contact surface corresponding to the tire shoulder position. The higher the slip rate, the higher the asymmetry of the stress distribution on both sides of the belt steel cord. At 65° and 67° belt angles, the distribution of grounding imprints on the tread are more uniform, and the tread is less prone to deformation, resulting in lower tread wear.

Influence of Different Angles in the Photobioreactor on Algal Biomass Growth with Optimized Poultry Excreta Leachate: A Batch-Scale Study

In this study, the influence of solar inclination angles on biomass growth and the biomolecule profile of Chlorella pyrenoidosa (C. pyrenoidosa) were analyzed in the vertical flat–panel photobioreactor (FPPBR). The growth of C. pyrenoidosa was analyzed at three different solar inclination angles (32.9°, 47.9°, and 90°) in a natural open environment with BG-11 medium and poultry excreta leachate (PEL). The maximum yield of biomass was obtained at 2.40 g/L with PEL and 1.45 g/L with BG-11 medium at a solar inclination angle of 47.9°. The biomass yield with PEL and BG-11 was 5.09–10.26%, 3.94–5.72%, respectively, while biomass productivity with PEL and BG-11 was 5.27–10.63%, 4.06–5.90% higher at a solar inclination angle of 47.9° as compared to 32.9°. The average temperature and radiation of FPPBR were recorded ≈3.90 ± 0.40% and ≈17.28 ± 2.23% higher at a solar inclination angle of 47.9° as compared to a solar inclination angle of 32.9°. The inclined radiation was acquired the maximum area of FPPBR. Results indicated that solar inclination angles enhanced the productivity of algae in FPPBR.

Heat and mass flux analysis of magneto-free-convection flow of Oldroyd-B fluid through porous layered inclined plate

The present work examines the analytical solutions of the double duffusive magneto free convective flow of Oldroyd-B fluid model of an inclined plate saturated in a porous media, either fixed or moving oscillated with existence of slanted externally magnetic field. The phenomenon has been expressed in terms of partial differential equations, then transformed the governing equations in non-dimensional form. On the fluid velocity, the influence of different angles that plate make with vertical is studied as well as slanted angles of the electro magnetic lines with the porous layered inclined plate are also discussed, associated with thermal conductivity and constant concentration. For seeking exact solutions in terms of special functions namely Mittag–Leffler functions, G-function etc., for Oldroyd-B fluid velocity, concentration and Oldroyd-B fluid temperature, Laplace integral transformation method is used to solve the non-dimensional model. The contribution of different velocity components are considered as thermal, mass and mechanical, and analyse the impacts of these components on the fluid dynamics. For several physical significance of various fluidic parameters on Oldroyd-B fluid velocity, concentration and Oldroyd-B fluid temperature distributions are demonstrated through various graphs. Furthermore, for being validated the acquired solutions, some limiting models such as Newtonian fluid in the absence of different fluidic parameters. Moreover, the graphical representations of the analytical solutions illustrated the main results of the present work and studied various cases regarding the movement of plate.

Investigation of the fuel-air flow inside a vortex furnace with a fluidized bed using a special air-distributing nozzle.

The search for resources alternative to fossil sources of thermal energy is a constant component of the development of the energy sector of any country. This issue is now most urgent due to various political processes and the constant decrease of the total amount of non-renewable natural resources. One of the ways to implement the issue of replacing natural gas, coal and other types of fossil fuels is the burning of waste from agriculture and the woodworking industry. But this is associated with a significant number of technical difficulties and an insufficient theoretical basis for implementation. The article presents the results of an experimental study of the fuel-air flow inside a fluidized-bed vortex furnace using a special air-distributing nozzle. A nozzle with a 15ͦ slope of the plates is used, which does not exceed 10% of the total area of ​​the free section of the chamber of the experimental setup. In the course of the experiment, the limiting conditions for the formation of a vortex flow at different amounts of fuel and different air flow rates are indicated, and the values ​​of pressure losses and flow rates are shown. So for 2.9 kg of sawdust, the maximum speed of formation of a vortex flow is 0.72 m/s, for 5.8 kg this value is 0.57 m/s. The results obtained make it possible to formulate recommendations for the improvement of existing solid fuel furnaces through the use of special nozzles to intensify combustion processes. In the future, it is planned to consider other types of solid fuel and the influence of different angles of inclination of the blades on the air distribution nozzle on the aerodynamic characteristics inside the vortex furnace. All this will make it possible to formulate recommendations for the improvement of existing solid fuel vortex furnaces.

Fluid-Structure Interaction of a Foiling Craft

Hydrofoils are a current hot topic in the marine industry both in high performance sailing and in new passenger transport systems in conjunction with electric propulsion. In the sailing community, the largest impact is seen from the America’s cup, where boats are sailed at more than 50 knots (over 100 km/h) with 100% “flying” time. Hydrofoils are also becoming popular in the Olympics, as in the 2024 Olympic games 5 gold medals will be decided on foiling boats/boards. The reason for the increasing popularity of hydrofoils and foiling boats is the recent advances in composite materials, especially in their strength to stiffness ratio. In general, hydrofoils have a very small wetted surface area compared to the wetted surface area of the hull. Therefore, after “take-off” speed, the wetted surface area of the hull, and consequently the resistance of the boat, is reduced considerably. The larger the weight of the boat and crew and the higher the speeds, the greater the loads on the hydrofoils will be. The current research investigates the interaction effects between the fluid and structure of the ZP00682 NACRA 17 Z-foil. The study is carried out both experimentally, in SSPA’s cavitation tunnel, and numerically using a fully coupled viscous solver with a structural analysis tool. The experimental methodology has been used to validate the numerical tools, which in turn are used to reverse engineer the material properties and the internal stiffness of the NACRA 17 foil. The experimental flow speed has been chosen to represent realistic foiling speeds found in the NACRA 17 class, namely 5, 7, and 9 m/s. The forces and the deflection of the Z-foil are investigated, showing a maximum deflection corresponding to 24% of the immersed span. Finally, the effects of leeway and rake angles on the bending properties of the Z-foil are investigated to assess the influence of different angles in sailing strategies, showing that a differential rake set-up might be preferred in search for minimum drag.

The thermal behavior of blood flow in the arteries with various radii and various stenosis angles using non-Newtonian Sisko model

In this work, the FVM method is employed to simulate blood flow behavior within stenosis arteries based on the non-Newtonian Sisko model by using UDF in Fluent. Stenosis is simulated in cone geometry, and influences of different angles of stenosis with different artery radii are studied on the Nusselt number and temperature of blood flow. It is observed that with increasing angles of stenosis and reducing internal radius, the artery is narrowed, which results in enhancement of Nusselt number of blood flow. Thus, the temperature of blood flow is reduced. Also, applying heat fluxes of q“ = 400 W/m2, q” = 800 W/m2, and q“ = 1000 W/m2 prepare temperature enhancement as much as 0.44 K, 0.89 K, and 1.15 K respectively which are important from a medical viewpoint. The maximum temperature is reported as much as 38.2 °C by applying heat flux of q” = 1000 W/m2, which is noticeable for the human body healthy, especially for the function of enzymes and other proteins of the body. Also, with increasing angles of stenosis and reducing internal radius, the artery is tightened and velocity of blood fluid is enhanced which affects blood circulation between tissues and the oxygenation process, temperature variation, and heat transfer alteration of blood flow within the human body. In reality, circulation of blood transfers heat between tissues, and the dimensions of the blood vessels are various, whenever more blood is needed in some vessels of the body due to more activity, these blood vessels expand to supply the required blood while other vessels tight to compensate it. Therefore, present mechanical research is applicable for medical science especially in surgical widening of a blocked or narrowed blood vessel.

Study on Mechanism of Structure Angle on Microstructure and Properties of SLM-Fabricated 316L Stainless Steel.

In this study, seven 316L stainless steel (316L SS) bulks with different angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°) relative to a build substrate were built via selective laser melting (SLM). The influences of different angles on the metallography, microstructure evolution, tensile properties, and corrosion resistance of 316L SS were studied. The 0° sample showed the morphology of corrugated columnar grains, while the 90° sample exhibited equiaxed grains but with a strong <101> texture. The 60° sample had a good strength and plasticity: the tensile strength with 708 MPa, the yield strength with 588 MPa, and the elongation with 54.51%. The dislocation strengthening and grain refinement play a vital role in the mechanical properties for different anisotropy of the SLM-fabricated 316L SS. The 90° sample had greater toughness and corrosion resistance, owing to the higher volume fraction of low-angle grain boundaries and finer grains.

Analysis on the Mechanical Stability of the Leg Joints in UHV Transmission Tower

Transmission line pole tower, whose safety and reliability will directly affect the safe and stable operation of the entire transmission line, is a rod-shaped and tower-shaped structure that supports overhead transmission line conductors and ground lines and maintains a certain distance between them and the ground. Moreover, the stress stability of the leg structure joints in UHV transmission towers is mainly analyzed in the paper. With the help of the finite element analysis software, taking the arrangement of the long and short legs in the actual structure of the tower as an example, the influence of different angles of the tower on the bending moment is compared and analyzed under the condition that the main material slenderness ratio is the same. Meanwhile, in order to eliminate the influence of horizontal force on the height of different tower legs, only the bending moment generated by the structural system at the tower legs under axial pressure is considered to continuously improve the stability and reliability of the line pole tower structure, so that the power safety can be guaranteed to a large extent.

Computational Analysis of Turbulent Hemodynamics in Radiocephalic Arteriovenous Fistulas to Determine the Best Anastomotic Angles

Hemodynamics has been known to play a major role in the development of intimal hyperplasia leading to arteriovenous fistula failure. The goal of our study is to investigate the influence of different angles of side-to-end radiocephalic anastomosis on the hemodynamic parameters that promote intimal dysfunction and therefore intimal hyperplasia. Realistic three-dimensional meshes were reconstructed using ultrasound measurements from distal side-to-end radiocephalic fistulas. The velocity at the proximal and distal radial inflows and at specific locations along the anastomosis and cephalic vein was measured through duplex ultrasound performed by a single examiner. A computational parametric study, virtually changing the inner angle of anastomosis, was performed. For this purpose, we used advanced computational models that include suitable tools to capture the pulsatile and turbulent nature of the blood flow found in arteriovenous fistulas. The results were analyzed in terms of velocity fields, wall shear stress distribution, and oscillatory shear index. Results show that the regions with high oscillatory shear index, which are more prone to the development of hyperplasia, are greater and progressively shift toward the anastomosis area and the proximal vein segment with the decrease of the inner angle of anastomosis. These results are specific to distal radiocephalic fistulas because they are subject to proximal and distal radial inflow. The results of this study show that inner anastomosis angles approaching 60-70° seem to yield the best hemodynamic conditions for maturation and long-term patency of distal radiocephalic fistulas. Inner angles greater than 90°, representing the smooth loop technique, did not show a clear hemodynamic advantage.

Transonic static aeroelastic and longitudinal aerodynamic characteristics of a low-aspect-ratio swept wing

Based on the CFD/CSD coupling method, the transonic static aeroelastic characteristics of the low-aspect-ratio swept wing was studied by numerical simulation. The Navier-Stokes equation was used as the fluid computational control equations. The flow field mesh deformation was performed using the Transfinite Interpolation method (TFI) method, and the data exchange on the CFD/CSD coupling interface was realized by the Constant Volume Transform (CVT) method. Based on the above method, the transonic static aeroelastic coupling calculation program was developed. The results of ONERA M6 wing static aeroelastic calculated by the coupling program were compared with wind tunnel test and reference results, and the effectiveness of the program was verified. Through numerical simulation, the influence of different angles of attack and Mach number on the static aeroelastic deformation and torsion angle of the wing are studied. Finally, by comparing the surface pressure cloud and pressure coefficient of the rigid wing and the elastic wing, the influence of static aeroelastic on the longitudinal aerodynamic characteristics and stability of the wing is mainly analyzed.

Research on HONDA NHX 110 fueled with biogas, CNG and E85

The work presents research on HONDA NHX 110 fueled with biogas, compressed natural gas – CNG, and the mixture of bioethanol with gasoline –E85. The experiment study was conducted on the author’s test bench which contained: internal combustion engine ICE – HONDA NHX 110, electrical machine, electrical loading unit, control chain which contain NI cards and prepared application in LabVIEW software for data acquisition. In herein work, the influence of different angles of the ignition advance on value change of an indicated pressure diagram(for a single cycle and average value), the electric power value, vibration acceleration of internal combustion body for biogas have been presented. The results discussed in this work convey practical information about the vibroacoustic activity, maintenance of internal combustion engine as distribution generation source (electricity generation state) which have been powered by alternative fuels.

Influence of Different Angles of File Access on Cyclic Fatigue Resistance of Reciproc and Reciproc Blue Instruments

IntroductionThe purpose of this study was to compare the cyclic fatigue of Reciproc (REC; VDW, Munich, Germany) and Reciproc blue (REB, VDW) with different angles of file access. MethodsThe cyclic fatigue resistance of 120 new REC R25 and REB R25 (REB) files was tested. Instruments were divided into 8 groups on the basis of the access angle inside the artificial canal tested (n = 15): groups 1, 2, 3, and 4 included REC tested at 0°, 10°, 20°, and 30°, respectively, and groups 5, 6, 7, and 8 consisted of REB tested at 0°, 10°, 20°, and 30°, respectively. Resistance to cyclic fatigue was determined by recording the time to fracture in a stainless steel artificial canal with a 60° curvature and a 5-mm radius using a customized testing device. Data were analyzed using 2-way analysis of variance followed by the post hoc Tukey test with a significance level of 5%. The fracture surface of fragments was examined with a scanning electron microscope. ResultsThe cyclic fatigue of REC was reduced from each angle of insertion, whereas REB reduced its fatigue resistance when 20° or 30°access inclination was tested. REB exhibited higher cyclic fatigue than REC when the angle of file access was 0° and 10° (P < .05), whereas there was no difference between the instruments tested at 20°. REC had higher cyclic fatigue resistance than REB at 30° (P < .05). ConclusionsREB files exhibited higher cyclic fatigue resistance than REC when the access to the canal was straight or with a limited inclination.

Analysis of Mechanical and Acoustic Emission Characteristics of Rock Materials with Double‐Hole Defects Based on Particle Flow Code

There are a lot of fissures, holes, and other defects in the formation of natural rocks. Under the influence of the external loads, these defects may cause engineering problems. Therefore, it is of great significance to analyze the characteristics of damage evolution of the defective rocks. In the study, the double‐hole defective rocks with different angles of the center connection line are considered and the numerical models are established firstly. Then the mechanical behavior and acoustic emission (AE) characteristics are analyzed systematically. Finally the laws of damage evolution of the defective rock materials are investigated based on the AE characteristics. The research results show that the stress‐strain behavior of the defective rocks can be divided into elastic stage, plastic stage and failure stages. The characteristics of acoustic emission evolution and laws of damage evolution are closely related to the stress‐strain relationship. The elastic modulus of the double‐hole defective rocks is similar with different angles of the center connection line, but the peak strength is different. The shape of the peak strength of these defective rocks is a W type owing to the different failure modes. The influences of different angles of the center connection line on the characteristics of AE evolution include the maximum events number, the strain value of the initial AE events and the maximum AE events, and the strain range of the serious AE events. Different angles of the center connection line have different influences on the laws of damage evolution of the double‐hole defective rocks.

Ultrafast surface plasmon-polariton interference and switching in multiple crossing dielectric waveguides

In this paper, we investigate propagation effects and interference switching of surface plasmon-polaritons (SPPs) in a junction of multiple crossed waveguides. These waveguides are produced on a thin gold layer by a simple photolithographic procedure. The waveguide dimensions are optimized for SPP excitation and propagation along two crossed input waveguides. At the waveguide intersection, different possibilities for SPP propagation into multiple output waveguides are offered. Using leakage radiation microscopy, we find that the SPPs preferably propagate into only one specific direction different from the direction of the input waveguides with avoidance of signal backscattering into the input direction. Furthermore, it is demonstrated that the SPP intensity at the output waveguide can be tuned by interference effects induced by a phase shift of the excitation laser beams. Additionally, we study the influence of different angles between the two input and the one specific output waveguides of the junction structure on the propagation properties of SPP modes in order to demonstrate a highest possible energy flux into the output waveguide. The experimental investigations are supported by finite-difference time-domain simulations. Good agreement between experimental results and numerical simulations is obtained. Applications of this effect are discussed for realization of ultrafast optical/plasmonic switches and optical logic gate structures with potential for integration and cascading.

Influence of Polishing Orientation on the Generation of LIPSS on Stainless Steel

We report on the influence of different angles between the electrical field of the impinging laser and the polishing direction of linearly polished surfaces on the generation of low spatial frequency LIPSS on stainless steel. The electrical field is rotated in a range of 0° to 90° with respect to the polishing direction and its effect on the orientation and homogeneity of the LIPSS is determined. In addition, the influences of the initial surface roughness and laser parameters such as the laser fluence on the generation of LIPSS are investigated. It can be shown, that the formation of LIPSS is driven by the initial surface roughness. The experimental results lead to the assumption that LIPSS were attracted by the linear grooves caused by polishing. Depending on the used parameter set, the orientation of the generated LSFL formation derived up to a value of 45° against the common predictions. Furthermore, a dependency of the required fluence for LSFL on surface roughness and polishing direction is demonstrated. Particularly, LSFL generated with a low fluence are more attracted by the surface polishing. Continuatively, the results may contribute to a further understanding of the underlying mechanisms involved in the generation of LIPSS. Moreover the results can be useful for producing LIPSS in large-scale for possible applications.

Influence of Different Angles of Reciprocation on the Cyclic Fatigue of Nickel-Titanium Endodontic Instruments

IntroductionThe purpose of this study was to evaluate cyclic fatigue fracture resistance of engine-driven nickel-titanium (K3XF) instruments under reciprocating movement in various angles. MethodsFifty K3XF size 40 taper 0.06 nickel-titanium instruments were divided randomly into 5 groups of 10 each. All instruments were subjected to cyclic fatigue tests. Instruments in groups 1–4 were tested by using different reciprocating motions, whereas instruments of group 5 (control group) were used in continuous rotation. All instruments were rotated or reciprocated until fracture occurred. Time to fracture was recorded, and data were statistically analyzed by using one-way analysis of variance, followed by Tukey honestly significant difference test for comparison between different groups. ResultsAll reciprocating groups (groups 1–4) showed a significant increase in time to failure when compared with group 5 (continuous rotation) (P < .05). Mean time was significantly higher in group 1, followed by group 2. No significant difference was found between groups 3 and 4 (P = .251). Increasing the clockwise angle of reciprocation and consequently increasing the angle of progression for each reciprocation cycle reduced the resistance to cyclic fatigue. ConclusionsMovement kinematics (reciprocating movements in various angles) had a significant influence on the cyclic fatigue life of the tested nickel-titanium instruments.

Peak Torque and IEMG Activity of Quadriceps Femoris Muscle at Three Different Knee Angles in a Collegiate Population

The coordinated activities of the four heads of the quadriceps femoris muscle results in knee extension. It is still a matter of debate as to whether the different heads of the quadriceps can be activated differentially by the central nervous system at different joint angles. This study aimed to investigate the influence of different angles of knee joint on the activation level of the vastus medialis oblique (VMO), vastus lateralis (VL) and rectus femoris (RF) using electromyographic activity during maximal voluntary isometric contraction (MVIC) and occurrence of peak torque measurement. Forty healthy subjects (20 males, 20 females) participated in the study. The peak torque for the dominant leg was measured using HUR5340 leg extension/curl with simultaneous recording of MVIC of the VMO, VL and RF using surface electromyography (SEMG). Test angles were presented randomly in 30° increments from 30° to 90° of knee flexion. To get peak torque, each subject performed maximal contraction of 10 seconds at each test angle and the myoelectrical activity was recorded simultaneously. The results illustrated that peak torque occurred at 60° for the entire group, including males ( F = 39.654, p F = 32, p F = 14.665, p F = 22.40, p