Application Of Mechanical Devices Research Articles

Effect of exoskeleton manipulator on hand function rehabilitation for postburn patients

Purpose Patients with scar contracture deformities caused by hand burns were treated with an exoskeleton manipulator system, which was equipped with games to explore its clinical application value. Methods Twenty patients who were treated for post-burn scars of bilateral hands between October 2020 and June 2021 were selected (ChiCTR2000036232). The patients were divided into two groups: control, 10 patients (traditional outpatient treatment); and experimental, 10 patients (exoskeleton manipulator system treatment). We compared the change in the total active motion (TAM) value, grip strength, scar improvement, and postoperative pain improvement. Results After 3 months of rehabilitation training, the improvement of thumb TAM was 33.80 ± 11.38 ° in the experimental group and 23.2 ± 6.13 ° in the control group. With respect to the index finger TAM, the improvement in the experimental and control groups was 84.50 ± 30.96 ° and 54.80 ± 15.89 °, respectively. The middle finger TAM of the experimental and control groups improved by 86.75 ± 32.85 ° and 60.25 ± 17.97 °, respectively. However, improvement of grip strength, scar score, and pain score were similar between the two groups. Conclusions The exoskeleton manipulator system has excellent effects in improving burned hand joint movement, which is suitable for hand burn patients and has beneficial clinical effects. Implications for rehabilitation Exercise is an effective means to improve the hand function of burn patients. The application of mechanical devices in the rehabilitation of burned hands can effectively help patients exercise. The A5 Hand Function Training System is an exoskeleton mechanical device that can exercise the small joints of the hand. It assists patients in using different computer games during treatment.

PVD coatings influence (TiCN, BCN, and CrAlN) on the fatigue life behavior of AISI 1045 steel for automotive applications

This work evaluated the influence of titanium carbo-nitride (TiCN), chromium aluminum nitride (CrAlN), and boron carbo-nitride (BCN) coatings deposited on AISI 1045 steel and their behavior in fatigue life. Suitable deposition parameters were established to obtain appropriate deposition times for polycrystalline growth and desired stoichiometry, as well as a stable layer thickness of ~ 3 μm. The physical and chemical properties of the obtained coatings were established by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nanoindentation. Scanning electron microscopy (SEM) was used for analyzing the fracture surfaces of the samples subjected to fatigue. The analysis of the fatigue behavior of the uncoated and coated substrates was performed under rotary bending conditions applying maximum alternating stresses in the interval of 55 to 70% of the ultimate strength value, i.e., from 479 to 610 MPa, respectively. The test was conducted at room temperature. It was established that the fatigue resistance properties increased for the three types of coated samples, TiCN, BCN, and CrAlN, with values of 9.6%, 4.2%, and 3.9%, respectively, calculated for 1 × 106 cycles. The highest value in fatigue life improvement corresponded to the TiCN coating. This is associated with the increase in the mechanical properties of the coating, as well as the lower presence of tensile type stresses. The mechanical and fatigue results found in these ternary coatings deposited on AISI 1045 steel open up the possibility of future applications in mechanical devices, e.g., automotive applications with high fatigue demands in service conditions.

Corrosion Nature in [CoN/AlN]n Multilayers Obtained from Laser Ablation

The aim of this work is the improvement of the electrochemical behavior of industrial steel using [CoN/AlN]n multilayered system via reactive Pulsed Laser Deposition (PLD) technique with a Nd: YAG laser (λ = 1064 nm) on Silicon (100) and AISI 302 steel substrates. In this work was varied systematically the bilayer period (Λ) and the coatings were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and the chemical composition was determined by means of X-ray photoelectron spectroscopy (XPS). The maximum corrosion resistance for the coating with (Λ) equal to 34.7 nm, corresponding to n = 30 bilayered. The polarization resistance and corrosion rate were around 7.62 × 105 kOhm × cm2 and 7.25 × 10−5 mm/year, these values were 6.3 × 105 and 78.6 times better than those showed by the uncoated 302 stainless steel substrate (1.2 kOhm × cm2 and 0.0057 mm/year), respectively. The improvement of the electrochemical behavior of the steel 302 coated with this [CoN/AlN]n can be attributed to the presence of several interfaces that act as obstacles for the inward and outward diffusions of Cl− ions, generating an increment in the corrosion resistance. The electrochemical results found in the [CoN/AlN]n open a possibility of future applications in mechanical devices that require high demands in service conditions.

Effects of Rotation on Transient Fluid Flow and Heat Transfer Through a Curved Square Duct: The Case of Negative Rotation

The fluid flow and heat transfer through a rotating curved duct has received much attention in recent years because of vast applications in mechanical devices. It is noticed that there occur two different types of rotations in a rotating curved duct such as positive and negative rotation. The positive rotation through the curved duct is widely investigated while the investigation on the negative rotation is rarely available. The paper investigates the influence of negative rotation for a wide range of Taylor number (<i>−10 ≤ Tr ≤ −2500</i>) when the duct itself rotates about the center of curvature. Due to the rotation, three types of forces including Coriolis, centrifugal, and buoyancy forces are generated. The study focuses and explains the combined effect of these forces on the fluid flow in details. First, the linear stability of the steady solution is performed. An unsteady solution is then obtained by time-evolution calculation and flow transition is determined by calculating phase space and power spectrum. When <i>Tr</i> is raised in the negative direction, the flow behavior shows different flow instabilities including steady-state, periodic, multi-periodic, and chaotic oscillations. Furthermore, the pattern variations of axial and secondary flow velocity and isotherms are obtained, and it is found that there is a strong interaction between the flow velocities and the isotherms. Then temperature gradients are calculated which show that the fluid mixing and the acts of secondary flow have a strong influence on heat transfer in the fluid. Diagrams of unsteady flow and vortex structure are further sketched and precisely elucidate the curvature effects on unsteady fluid flow. Finally, a comparison between the numerical and experimental data is discussed which demonstrates that both data coincide with each other.

Nonlocal Reddy beam model for free vibration analysis of multilayer nanoribbons incorporating interlayer shear effect

Abstract The aim of this study is to investigate the interlayer shear effect on nonlocal free vibration of multilayer graphene nanoribbons (MLGNRs) based on Reddy beam theory. The major novelty of the study is using the higher order shear deformation theory of Reddy to take the van der Waals’ interaction of the layers into account and calibrating the nonlocal parameter with the aids of molecular dynamics (MD) simulations to match the best results. Furthermore, the shear correction factor of nonlocal Timoshenko theory is calculated for modeling the MLGNRs. MLGNRs have broad applications in mechanical devices, such as resonators, sensors and actuators. Accordingly the present results can be used as a reference for future works in which the interlayer shear effects has substantial influences on the mechanical behavior of MLGNRs. The present study outstands for its modeling simplicity and low computational time and cost as well as excellent accuracy.

나노유체와 기계장치에의 응용

나노유체와 기계장치에의 응용

Enlargement of Beam Coverage in FSO Mobile Network

Pointing, acquisition and tracking of a free-space optical node in a mobile network experiencing misalignment due to adverse factors including vibration, motion and atmospheric turbulence requires a different approach than traditional free-space optical transceivers. A recent fiber-bundle approach for beam steering at the transmitter was investigated to provide continuous beam coverage at the receiver without the application of mechanical devices. Utilizing multiple fibers-lenses sets at the receiver was also proposed to enhance the tolerance of optical link misalignment. This paper investigates the feasibility of applying multiple fibers with a single lens at the transmitter and multiple fiber-lenses sets at the receiver to improve the transmission performance on tolerating link misalignment. Two series of laboratorial experiments were implemented to compare the optical link robustness for different transceiver setups as the fiber-lens distance (zfl) was varied to modify the beam divergence: multi-fiber transmitter working with single-fiber-lens receiver and multi-fiber transmitter working with multi-fiber-lens receiver. The results showed that using multiple fibers in both the transmitter and the receiver reveals significant potential to maximize the up time of the link.

Educational Technology One

Educational technology is no more than the application of mechanical devices to the learning process. It has been over‐written and over‐rated; but it still applies that the machinery and software involved are an adjunct to the central educational process and not a place to or a panacea for pedagogical ills.

Application of mechanical devices to the assistance of manual operating in telephone exchanges

Application of mechanical devices to the assistance of manual operating in telephone exchanges

Discussion on “Application of mechanical devices to the assistance of manual operating in telephone exchanges”

Discussion on “Application of mechanical devices to the assistance of manual operating in telephone exchanges”