Function Of Force Research Articles

Active contour model based on hybrid signed pressure force function

AbstractTo segment noisy and multi‐target images, an active contour model based on a hybrid signed pressure force function that fuses global and local information of the image is proposed. Firstly, a local signed pressure force function is defined using the local area information of the image. Then, it is combined with the existing global grey density function to construct a new signed pressure force function. Finally, the selective binary and Gaussian filtering regularized level set are modified using the newly defined function. Extensive experiments and comparisons on both synthetic and real images demonstrate that the proposed method is robust to noise and can handle noisy and multi‐target images with high accuracy.

Formulation for Multiple Cracks Problem in Thermoelectric-Bonded Materials Using Hypersingular Integral Equations

New formulations are produced for problems associated with multiple cracks in the upper part of thermoelectric-bonded materials subjected to remote stress using hypersingular integral equations (HSIEs). The modified complex stress potential function method with the continuity conditions of the resultant electric force and displacement electric function, and temperature and resultant heat flux being continuous across the bonded materials’ interface, is used to develop these HSIEs. The unknown crack opening displacement function, electric current density, and energy flux load are mapped into the square root singularity function using the curved length coordinate method. The new HSIEs for multiple cracks in the upper part of thermoelectric-bonded materials can be obtained by applying the superposition principle. The appropriate quadrature formulas are then used to find stress intensity factors, with the traction along the crack as the right-hand term with the help of the curved length coordinate method. The general solutions of HSIEs for crack problems in thermoelectric-bonded materials are demonstrated with two substitutions and it is strictly confirmed with rigorous proof that: (i) the general solutions of HSIEs reduce to infinite materials if G1=G2, K1=K2, and E1=E2, and the values of the electric parts are α1=α2=0 and λ1=λ2=0; (ii) the general solutions of HSIEs reduce to half-plane materials if G2=0, and the values of α1=α2=0, λ1=λ2=0 and κ2=0. These substitutions also partially validate the general solution derived from this study.

Multimodal Image Registration Using a Viscous Fluid Model with the Bhattacharyya Distance.

Image registration is an elementary task in medical image processing and analysis, which can be divided into monomodal and multimodal. Direct 3D multimodal registration in volumetric medical images can provide more insight into the interpretation of subsequent image processing applications than 2D methods. This paper is dedicated to the development of a 3D multimodal image registration algorithm based on a viscous fluid model associated with the Bhattacharyya distance. In our approach, a modified Navier-Stoke's equation is exploited as the foundation of the multimodal image registration framework. The hopscotch method is numerically implemented to solve the velocity field, whose values at the explicit locations are first computed and the values at the implicit positions are solved by transposition. The differential of the Bhattacharyya distance is incorporated into the body force function, which is the main driving force for deformation, to enable multimodal registration. A variety of simulated and real brain MR images were utilized to assess the proposed 3D multimodal image registration system. Preliminary experimental results indicated that our algorithm produced high registration accuracy in various registration scenarios and outperformed other competing methods in many multimodal image registration tasks.Clinical Relevance- This facilitates the disease diagnosis and treatment planning that requires accurate 3D multimodal image registration without massive image data and extensive training regardless of the imaging modality.

The mitochondrially targeted peptide elamipretide (SS-31) improves ADP sensitivity in aged mitochondria by increasing uptake through the adenine nucleotide translocator (ANT)

Aging muscle experiences functional decline in part mediated by impaired mitochondrial ADP sensitivity. Elamipretide (ELAM) rapidly improves physiological and mitochondrial function in aging and binds directly to the mitochondrial ADP transporter ANT. We hypothesized that ELAM improves ADP sensitivity in aging leading to rescued physiological function. We measured the response to ADP stimulation in young and old muscle mitochondria with ELAM treatment, in vivo heart and muscle function, and compared protein abundance, phosphorylation, and S-glutathionylation of ADP/ATP pathway proteins. ELAM treatment increased ADP sensitivity in old muscle mitochondria by increasing uptake of ADP through the ANT and rescued muscle force and heart systolic function. Protein abundance in the ADP/ATP transport and synthesis pathway was unchanged, but ELAM treatment decreased protein s-glutathionylation incuding of ANT. Mitochondrial ADP sensitivity is rapidly modifiable. This research supports the hypothesis that ELAM improves ANT function in aging and links mitochondrial ADP sensitivity to physiological function.Graphical abstractELAM binds directly to ANT and ATP synthase and ELAM treatment improves ADP sensitivity, increases ATP production, and improves physiological function in old muscles. ADP (adenosine diphosphate), ATP (adenosine triphosphate), VDAC (voltage-dependent anion channel), ANT (adenine nucleotide translocator), H+ (proton), ROS (reactive oxygen species), NADH (nicotinamide adenine dinucleotide), FADH2 (flavin adenine dinucleotide), O2 (oxygen), ELAM (elamipretide), –SH (free thiol), –SSG (glutathionylated protein)

Functional performance and impact on the quality of life of three treatment strategies for mandibular edentulism: Results of a parallel 3-group cross-sectional study

ObjectivesThis parallel cross-sectional study compared masticatory function and patient-centered outcomes among 3 removable treatment strategies for mandibular edentulism. MethodsThirty-six edentulous participants rehabilitated using 3 removable treatment strategies for mandibular edentulism were allocated to one of the three groups (n=12): CCD (control), 2-IMO, and 3-IMO. Narrow diameter implants were installed using single-stage surgery and conventionally loaded with stud abutments. After 3 months of usage, the quality of life, maximum bite force, and masticatory function were evaluated. Data were analyzed with the Kruskal-Wallis test and post hoc pairwise Mann–Whitney tests with Bonferroni correction (α=0.05). ResultsThe 2-IMO and 3-IMO wearers did not show significant differences in any outcome, except for the 2 domains of 3-IMO wearers quality of life that obtained better Pain and General Performance scores. Both IMO groups presented significantly higher maximum bite force than CCD wearers. The 2-IMO wearers showed superior outcomes to the CCD group in all outcomes of the masticatory performance test and the X50, B and ME5.6 outcomes of the swallowing threshold test (p = 0.01), while 3-IMO participants only showed superior masticatory performance in terms of lower X50 values (19.86%, p = 0.02) and higher ME 2.8 (141.15%, p = 0.04) than CCD wearers. ConclusionsCompared to 2-IMO wearers, 3-IMO wearers report superior impact of treatment on daily living activities in the Pain and General Performance domains. 2-IMO and 3-IMO wearers showed no significant differences between them for all evaluated bite force and masticatory function parameters. Clinical SignificanceAlthough overdentures retained by 3 implants (3-IMO) provide biomechanical advantages over those retained by 2 implants (2-IMO), superior clinical and functional effectiveness is not yet proven.

Stability Calculation of the Plane Steel Frame Structures Using Tangent Modulus Theory

This paper considers the phenomenon of the instability of steel plane frame structures in the elastic–plastic domain. The numerical analysis uses finite element method, where the corresponding stiffness matrices are based upon the trigonometric and hyperbolic interpolation functions of normal forces. The tangent modulus concept is applied when buckling occurs in the plastic range. Thus, the stiffness matrices for nonlinear material behavior are also derived. The procedure for determining effective length factors of compressed columns, which implies a global stability analysis of entire frames, is established too. It means that the proposed approach is based on the assumption that the collapse of the structure occurs when the most loaded columns reach their stability limit. So, the presented procedure enables the calculation of the real critical load of plane frame structures in the elastic–plastic domain and determines the corresponding effective length factors.

AVERAGED CIRCULAR SPATIAL RESTRICTED THREE-BODY PROBLEM: INTERNAL CASE, NEW RESULTS

We investigate the spatial restricted circular three-body problem in the nonresonant case. Namely, we apply Gaussian averaging to obtain averaged equations in terms of osculating elements and then investigate them. Keplerian ellipse with a focus in the main body (the Sun) is taken as an unperturbed orbit assuming the semi-major axis of the ellipse to be less than the radius of the orbit of the outer planet (internal problem). Using the Parseval formula we have derived the twice-averaged perturbed force function of the problem in the form of an explicit analytical series with coefficients expressed in terms of the Gauss and Clausen hypergeometric functions. An investigation of averaged force function along it’s curves of non-analyticity showed that the series are asymptotic by Poincaré. For a reduced system with one degree of freedom, phase portraits of oscillations in the plane of the Keplerian elements \(e\), \(\omega \) are constructed in the second and fourth approximations. It is shown the topology of the phase portrait is more complicated in fourth approximation then in first and second approximations provided that the constant \({{c}_{1}}\) of the Lidov–Kozai integral belongs to the interval (0, 0.382).

Deformation state of the load-bearing structure of a four-column the press

During the operation of each machine, the deformation and stress state of its supporting structure is directly related to the load. The load intensity ranges from the minimum to the maximum value and is a function of nominal force, torque, and kinematic-dynamic values of moving and executive assemblies during the machine operation process. The intensity of deformations is also a function of the shape and type of the supporting structure. However, although the supporting structure is reliable, which refers to its integrity, the production of a quality workpiece (product) does not have to be reliable. Therefore, it is important that the deformation states of the supporting structure be in the appropriate tolerance field, regardless of the intensity of the load. If the intensity of deformations is outside a certain field, it will directly affect the quality of the workpiece that is made on the subject machine. It is known that load-bearing structures can be of open and closed types, load-bearing structures of closed type are used for higher loads and larger workpiece dimensions. By installing sensors on the elements of the supporting structure with accompanying measuring chains in real-time, the deformation state of certain elements or places on the supporting structure can be monitored, based on which the reliable quality of the workpiece can be influenced.

CNC machining optimization of hydro-turbine runner blade based on VERICUT

Aiming at the problem of low production efficiency caused by the unreasonable setting of cutting parameters for CNC machining of hydro-turbine runner blade, the Force module of VERICUT software is used to analyze and compare the cutting force, the cutting power, and the material removal rate of the blade under different cutting parameters, find the cutting parameters that can give full play to the machining capacity of the machine tool, and use the optimization function of Force to automatically adjust the feed speed in the machining program. The test results show that after the optimization of cutting parameters, the production efficiency of the NC machining program is significantly improved, and the cutting power of the machine tool spindle is stable.

Nuclear Spin-Isospin Response within the Fayans Functional

An effective approximation to a fully self-consistent global description of the total force function of b decay within the framework of the theory of finite Fermi systems is presented, based on the calculation of ground states within the framework of the modified energy density functional of Fayans et al. (DF3-f) and the continuum quasiparticle random phase approximation (CQRPA). The isovector parameter ℎ2− of the volume part of the functional has been refined, the permissible range of which was determined earlier by us from restrictions on the parameters of the equation of state for nuclear matter—the symmetry energy and its derivative at equilibrium density, obtained from a joint analysis of the value of the ‘‘neutron skin’’ ΔRnp of the nuclei 208Pb and 48Ca, found in the PREX-II and CREX experiments, results of ab initio calculations of the properties of the ground states of nuclei with the interaction of N3LO and systematics of data on the masses of neutron stars from astrophysical observations. New calculations of the Gamow–Teller strength functions for the reference doubly magic nuclei 208Pb and 132Sn, as well as for the nucleus 130Sn with developed neutron pairing have been carried out. In the proposed model, the global DF3-a + CQRPA calculations of beta-decay half-lives of heavy (quasi)spherical nuclei with Z = 81–83 and T1/2 240 s are conducted. Experimental lifetimes are described with accuracy up to factor 5.

Influence of an induced magnetic field on double diffusion convection for peristaltic flow of thermally radiative Prandtl nanofluid in non-uniform channel

Mathematical simulation of biological fluids is incredibly significant due to its use in many fields of medicine. Understanding various biological flows requires knowledge of the peristaltic process. Furthermore, nanoparticles play vital roles in several engineering and industrial procedures, including those related to heat exchangers, boilers, cooling systems, chemical engineering, MEMS, cool automobile engines, and laser diode arrays. The major goal of this study is to investigate the mathematical simulation of biological fluids, which holds significant implications in the field of biomechanics. Examples include the understanding of chyme motion in the gastrointestinal tract and the potential application in surgeries to control blood flow by manipulating the intensity of the magnetic field. The present analysis is to explore the peristaltic flow with double diffusion convection of magnetohydrodynamic Prandtl nanofluids in non-uniform channel having thermal radiation and viscous dissipation. The mathematical model is based on equations for continuity, temperature, nanoparticle fraction, momentum, induction, and concentration. The method of long wavelength and low Reynolds number is utilized. The numerical solution for concentration, pressure gradient, nanoparticle volume fraction, stream function, magnetic force function, pressure rise, velocity, and temperature are computed. Then the results of different parameters are represented graphically. The results outcomes are compared with the findings of limiting situations for verification. The main result of the present study is that the fraction of nanoparticles decreases with a rising significance of Dufour and Prandtl numbers because the effects of mass transfer are minimized by the effects of heat transmission. Moreover, a rise in the Dufour number boosts the fluid's temperature because heat is transmitted across boundaries more efficiently.

Thermal coupling model of a traveling flexible printing electronical membrane subjected to nonlinear electrostatical force

A flexible printing electronical membrane is an electron equipment made by precisely spraying conductive metal ink such as silver on a soft membrane substrate. With its advantages of light weight and flexibility, it can adapt to changing working environments and is widely used in aerospace, wearable electronics and other fields. Nevertheless, during the manufacturing preparation of roll-to-roll printing membranes, the high-speed movement of printing electronical membranes under tension is affected by the impact of hot air from the drying oven and the electrostatic interference generated by friction in transmission, which restricts the overprint accuracy and preparation velocity of flexible electronical membranes. To address this issue, the nonlinear forced vibrational characteristics of a traveling flexible printing electronical membrane on temperature coupling subjected to nonlinear electrostatic force were investigated. The roll-to-roll printed intelligent RFID electron membrane is the research target. On the basis of the energy approach and the heat conduction equation considering the effect of deformation, the nonlinear vibrational equations of an axially traveling flexible printing electronical membrane coupled with temperature under the function of nonlinear electrostatical excitation force were derived. The Bubnov–Galerkin algorithm was applied to discretize the vibration partial differential equations; by making full use of the quartic Runge–Kutta numerical algorithm to calculate the approximate solution of equations, the phase portraits, Poincaré maps, time history diagrams, power spectra, and bifurcation plots of the nonlinear vibrations of the traveling printing electronical membrane were used to explore the effects of movement velocities, electrostatical field, and thermal coupling coefficients. The findings obtained the stable working domain and the divergence instability domain of the traveling flexible printing electronic membrane, which provided a theory fundamental for enhancing the stable craft of a printing electronical membrane.

A Potential Nontraditional Approach To Combat tmexCD1-toprJ1-Mediated Tigecycline Resistance: Melatonin as a Synergistic Adjuvant of Tigecycline.

The emergence of TMexCD1-TOprJ1, a novel transferable resistance-nodulation-division (RND)-type efflux pump conferring resistance to tigecycline, is now a serious public health issue in the world. Here, we found that melatonin synergistically enhanced the antibacterial efficacy of tigecycline against tmexCD1-toprJ1-positive Klebsiella pneumoniae by disrupting the proton driving force and efflux function to promote the accumulation of tigecycline into cells, damaging cell membrane integrity and causing the leakage of cell contents. The synergistic effect was further validated by a murine thigh infection model. The results revealed that the melatonin/tigecycline combination is a potential therapy to combat resistant bacteria carrying the tmexCD1-toprJ1 gene.

A framework of high-order wheel polygonal wear mitigation for China's high-speed trains

High-order wheel polygonal wear is a significant concern on China’s high-speed trains; thus far, no satisfactory solution to prevent polygonal wear has been provided. In this study, a simplified vehicle-track coupling dynamic model was established, and the frequency response functions (FRF) of the wheel-rail force were obtained under multiple wheelsets conditions. After integrating a wheel-rail wear model, the rail localized bending modes (RLBM) were recognized as critical factors for the amplitude-frequency and phase-frequency properties of the wheel-rail force response and further gave rise to the growth of high-order polygonal wear. Consequently, rail dynamic vibration absorbers (DVA) were introduced into the vehicle-track coupling dynamic model as single-degree-of-freedom rigid bodies arranged at equal intervals along the track. The influencing mechanism of rail DVAs on the rail localized bending resonance, as well as the resulting polygonal wear, was investigated in detail. Results suggested that the rail localized bending resonance could be easily suppressed when the tuned frequency of the rail DVAs approaches the resonance frequency. However, due to newly generated resonance peaks, the polygonal wear was observed to persist. The phase-frequency property of the wheel-rail force response is a determining contributor to the growth trend of polygonal wear; therefore, the rail-tuned DVA should be designed to force the phase lag out of the positive growth region, namely 90° to 270°. Our results indicated that a DVA with a tuned frequency of 450 Hz could effectively slow the development of high-order polygonal wear on China’s high-speed trains, and the shorter installation interval of rail DVAs improves the suppression effect. This study proposed a phase-based design rule for rail DVAs to achieve wheel-rail periodic wear mitigation.

Non‐Newtonian fluid flow with the influence of induced magnetic field through a curved channel under peristalsis

AbstractIn this study, we investigated the influence of the induced magnetic field on the Jeffrey fluid under peristalsis through the curved channel. The governing equations, such as the continuity equation, momentum equation, and magnetic force functions, are formulated. The lengthy equations are shortened by considering the approximations of the tiny Reynolds number and the long wavelength. From the resulting reduced equations, the exact solution is determined. Graphs are used to explain the graphical results of the impact of important parameters of velocity, magnetic force function, current density, induced magnetic field, pressure rise, and stream functions.

Multi-Objective Optimization Design of Micro-Texture Parameters of Tool for Cutting GH4169 during Spray Cooling

This study explores the performance of micro-textured tools when cutting GH4169 during spray cooling. First, the morphologies of the micro-textures were selected according to the simulation and experiments. Secondly, cutting experiments were carried out during spray cooling. As appropriate for each experiment, regression models of cutting force, cutting temperature, or tool wear area were established, and variance analysis was conducted. The cutting force, cutting temperature, and tool wear area functions were obtained from the respective regression models. Based on these functions, the micro-texture parameters were optimized using the response surface method with the cutting force, cutting temperature, and rake face wear area as the objectives. Finally, a full factor experiment on the micro-texture parameters was designed using Minitab, and cutting experiments were conducted using micro-textured tools with these parameters. Taking a relatively low cutting force, cutting temperature, and tool wear as the objectives, a genetic algorithm multi-objective optimization model for the micro-texture parameters of the tools was established, and the model was solved using the NSGA-II algorithm to obtain a Pareto solution set and micro-texture parameters with a good, comprehensive cutting performance. The micro-texture morphology and parameters obtained in this study can also be used for cutting other high-temperature alloy materials with similar properties to GH4169. This research method can also be used to optimize micro-textured tools for cutting other materials.

Conceptual design, parameter optimization and performance investigation of a 10MW semi-submersible floating wind turbine in shallow water

There is lacking of floating wind turbine supporting large wind turbine, i.e. 10 MW, aiming at shallow water applications. In this paper, a 10 MW semi-submersible floating wind turbine named OUCwind is proposed for shallow water, and a scale optimization procedure is proposed during the preliminary design stage. It offers an engineering-practical method to determine the main parameters of a new-proposed floater, and critical floater characteristics, such as floater stability, natural period, platform mass etc. are chosen as important design criteria. The hydrodynamic performance with different scale parameters are investigated and it is found that enlarging distance between columns is a cost-effective way to get better stability and hydrodynamic performance. The structural performance of the new-designed OUCwind floater are compared with other two well-known braceless 10 MW platforms, 10 MW-CSC, and OO-star. From the frequency-domain analysis results, the surge linear transfer function, mean drift force and quadratic transfer function near the surge natural frequency of OUCwind is relatively small compared with other two platforms. In the time domain, the new-designed OUCwind also performs better in surge motion and mooring line tension response compared with 10 MW-CSC and OO-star, especially under extreme condition. Nevertheless, for the heave and pitch motions, the wave-frequency response of the OUCwind platform is relatively large under extreme load conditions.

Catch bonds in sickle cell disease: Shear-enhanced adhesion of red blood cells to laminin

Could the phenomenon of catch bonding—force-strengthened cellular adhesion—play a role in sickle cell disease, where abnormal red blood cell (RBC) adhesion obstructs blood flow? Here, we investigate the dynamics of sickle RBCs adhering to a surface functionalized with the protein laminin (a component of the extracellular matrix around blood vessels) under physiologically relevant microscale flow. First, using total internal reflectance microscopy we characterize the spatial fluctuations of the RBC membrane above the laminin surface before detachment. The complex dynamics we observe suggest the possibility of catch bonding, where the mean detachment time of the cell from the surface initially increases to a maximum and then decreases as a function of shear force. We next conduct a series of shear-induced detachment experiments on blood samples from 25 sickle cell disease patients, quantifying the number and duration of adhered cells under both sudden force jumps and linear force ramps. The experiments reveal that a subset of patients does indeed exhibit catch bonding. By fitting the data to a theoretical model of the bond dynamics, we can extract the mean bond lifetime versus force for each patient. The results show a striking heterogeneity among patients, both in terms of the qualitative behavior (whether or not there is catch bonding) and in the magnitudes of the lifetimes. Patients with large bond lifetimes at physiological forces are more likely to have certain adverse clinical features, like a diagnosis of pulmonary arterial hypertension and intracardiac shunts. By introducing an in vitro platform for fully characterizing RBC-laminin adhesion dynamics, our approach could contribute to the development of patient-specific antiadhesive therapies for sickle cell disease. The experimental setup is also easily generalizable to studying adhesion dynamics in other cell types, for example, leukocytes or cancer cells, and can incorporate disease-relevant environmental conditions like oxygen deprivation.

A non-ordinary state decomposition method for three-body potential peridynamics model

A non-ordinary state decomposition method is proposed for the bond shear form of three-body potential peridynamics (PD) model. To accomplish this formulation, the effective relative displacement between two points is first decomposed into the volumetric and deviatoric parts based on the definition of dilatation. Starting from this, we give decomposition forms of the elementary deformations and strain energy density of this PD model and finally express the PD force function in the form of the sum of dilatational and distortional parts, which enable the PD model to clearly reflect material response dependence on volume changes and shape distorsion. Combined with the computational scheme of strain and stress tensors presented in the paper, the proposed method is validated numerically. The study permits the possibility of introducing plastic incompressibility for the three-body potential PD model.

A decoupled physics-informed neural network for recovering a space-dependent force function in the wave equation from integral overdetermination data

A decoupled physics-informed neural network for recovering a space-dependent force function in the wave equation from integral overdetermination data