Simulation of Nanofibers Movement for Near-Field Electrospinning

2009 ◽  
Vol 60-61 ◽  
pp. 456-460 ◽  
Author(s):  
Hong Lian Wang ◽  
Gao Feng Zheng ◽  
Dao Heng Sun
Keyword(s):  
Narrow Range ◽  
Near Field ◽  
Center Of Mass ◽  
Resistance Force ◽  
Mass Center ◽  
Air Resistance ◽  
Movement Distance ◽  
Initial Spacing ◽  
Electric Field Force ◽  
Final Spacing

NFES is a new and simple way to realize precision-positioning of nanofiber. A model on NFES nanofiber movement is built to analyze the effects of the existed nanofibers which have been collected on the substrate, on the nanofiber’s dropping movement. During electrospinning nanofiber is affected by the electric field force, Coulomb repulsive force, air resistance force gravity and so on. The influence of parameters on the deposition behavior of as-spun nanofiber is discussed. The simulation results show that (i) with charge density increasing, the final spacing between mass center of nanofibers A and B (FSAB) increases and the movement distance of center-of-mass of nanofiber B (MDB) decreases first and then increases; (ii) FSAB increases with applied voltage, but decreased in narrow range with concentration of PEO increasing; (iii) FSAB decreased with the initial spacing between mass center of nanofibers A and B (ISAB) increasing, and then it increases after reaching the minimum. So does ISAB to DMB. This simulation model would improve the controlling of nanofiber in NFES.

Detection of Vehicle Tripped and Untripped Rollovers by a Novel Index With Mass-Center-Position Estimations

2017 ◽  
Author(s):  
Fengchen Wang ◽  
Yan Chen
Keyword(s):  
Load Transfer ◽  
Center Of Mass ◽  
Roll Motion ◽  
Mass Center ◽  
Motion Models ◽  
Center Position ◽  
Before And After ◽  
Vehicle Rollover ◽  
Lift Off ◽  
Rollover Index

This paper presents a novel mass-center-position (MCP) metric for vehicle rollover propensity detection. MCP is first determined by estimating the positions of the center of mass of one sprung mass and two unsprung masses with two switchable roll motion models, before and after tire lift-off. The roll motion information without saturation can then be provided through MCP continuously. Moreover, to detect completed rollover statues for both tripped and untripped rollovers, the criteria are derived from d’Alembert principle and moment balance conditions based on MCP. In addition to tire lift-off, three new rollover statues, rollover threshold, rollover occurrence, and vehicle jumping into air can be all identified by the proposed criteria. Compared with an existing rollover index, lateral load transfer ratio, the fishhook maneuver simulation results in CarSim® for an E-class SUV show that MCP metric can successfully predict the vehicle impending rollover without saturation for untripped rollovers. Tripped rollovers caused by a triangle road bump are also successfully detected in the simulation. Thus, MCP metric can be successfully applied for rollover propensity prediction.

scholarly journals ЗОВНІШНЯ БАЛІСТИКА СНАРЯДУ БМ1 ВИПУЩЕНОГО З Т-12 (МТ-12)

World Science ◽  
2020 ◽  
Vol 1 (1(53)) ◽  
pp. 23-29
Author(s):  
Величко Лев Дмитрович ◽  
Горчинський Ігор Володимирович ◽  
Сорокатий Микола Іванович
Keyword(s):  
Atmospheric Pressure ◽  
Sound Speed ◽  
Functional Dependence ◽  
Resistance Force ◽  
Kinematic Parameters ◽  
Muzzle Velocity ◽  
Velocity Magnitude ◽  
Air Resistance ◽  
The Mathematical Model

The magnitudes of the kinematic parameters of projectiles motion in the air depends on deterministic (form of projectile, its mass, temperature of air and charge, atmospheric pressure, derivation) and nondeterministic (muzzle velocity, magnitude and direction of wind velocity) values. During the projectile movement, its weight and frontal air resistance force have a determining influence on its dynamics. In the article it is investigated proposed by authors the mathematical model of determination of the functional dependence of the magnitude of the frontal air resistance force of the projectile’s motion on its velocity, mass and caliber, geometric characteristics, temperature and density of air, atmospheric pressure, sound speed in air. Since the trajectory of movement of the BM1 projectile released from the T-12 (MT-12) is canopy, it is assumed that during the projectile’s flight the air temperature and atmospheric pressure are unchanged and equal to their value at the point of the gun.

scholarly journals BraggNN: fast X-ray Bragg peak analysis using deep learning

IUCrJ ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhengchun Liu ◽  
Hemant Sharma ◽  
Jun-Sang Park ◽  
Peter Kenesei ◽  
Antonino Miceli ◽  
...  
Keyword(s):  
Deep Learning ◽  
Near Field ◽  
Center Of Mass ◽  
Computational Cost ◽  
Ground Truth ◽  
High Energy ◽  
Peak Shape ◽  
X Ray ◽  
Shape Fitting ◽  
Performance Improvements

X-ray diffraction based microscopy techniques such as high-energy diffraction microscopy (HEDM) rely on knowledge of the position of diffraction peaks with high precision. These positions are typically computed by fitting the observed intensities in detector data to a theoretical peak shape such as pseudo-Voigt. As experiments become more complex and detector technologies evolve, the computational cost of such peak-shape fitting becomes the biggest hurdle to the rapid analysis required for real-time feedback in experiments. To this end, we propose BraggNN, a deep-learning based method that can determine peak positions much more rapidly than conventional pseudo-Voigt peak fitting. When applied to a test dataset, peak center-of-mass positions obtained from BraggNN deviate less than 0.29 and 0.57 pixels for 75 and 95% of the peaks, respectively, from positions obtained using conventional pseudo-Voigt fitting (Euclidean distance). When applied to a real experimental dataset and using grain positions from near-field HEDM reconstruction as ground-truth, grain positions using BraggNN result in 15% smaller errors compared with those calculated using pseudo-Voigt. Recent advances in deep-learning method implementations and special-purpose model inference accelerators allow BraggNN to deliver enormous performance improvements relative to the conventional method, running, for example, more than 200 times faster on a consumer-class GPU card with out-of-the-box software.

Mass Center of Planar Mechanisms Using Auxiliary Parallelograms

1999 ◽  
Vol 121 (1) ◽  
pp. 166-168 ◽  
Author(s):  
A. Gokce ◽  
S. K. Agrawal
Keyword(s):  
Degrees Of Freedom ◽  
Center Of Mass ◽  
Mass Center ◽  
Planar Mechanisms ◽  
Physical Point ◽  
Planar Mechanism ◽  
Test Beds

Center of mass is an important property of a mechanism. In biomechanics, in many studies, one monitors the motion of this point. The center of mass has importance in development of gravity compensated exercise machines and test beds on earth that mimic the behavior of systems in space. In this paper, a method is described where auxiliary parallelograms are added to a planar mechanism to identify the location of the center of mass of the original mechanism. In this procedure, the original and the augmented mechanisms have the same number of degrees-of-freedom. During motion, the center of mass is a physical point which can be monitored or used for purposes motivated from the application.

Inertia Parameters Identification of Motor Assembly for Electric Vehicles Based on Modal Test Method

2013 ◽  
Vol 470 ◽  
pp. 534-538 ◽  
Author(s):  
Li Zhao He ◽  
Peng Yu ◽  
Tong Zhang ◽  
Rong Guo
Keyword(s):  
Error Analysis ◽  
Electric Vehicles ◽  
Center Of Mass ◽  
Moment Of Inertia ◽  
Test Method ◽  
Mass Center ◽  
Test Error ◽  
Modal Test ◽  
Drive Motor ◽  
Inertia Parameters

Inertia parameters are essential for motor assembly mounting design, which mainly includes the mass, center of mass (CM) coordinates, moment of inertia and product of inertia. This paper explains the principle and methods of modal test method. One vehicle drive motor assembly is taken as the research object, its inertia parameters are identified using this modal test method. Finally test error analysis is also performed.

Effect of Trunk Segment Boundary Definitions on Frontal Plane Segment Inertial Calculations

2018 ◽  
Vol 34 (3) ◽  
pp. 232-235 ◽  
Author(s):  
Zachary Merrill ◽  
Grace Bova ◽  
April Chambers ◽  
Rakié Cham
Keyword(s):  
Center Of Mass ◽  
Frontal Plane ◽  
Dual Energy ◽  
Segment Length ◽  
Radius Of Gyration ◽  
Morbidly Obese ◽  
Mass Center ◽  
X Ray ◽  
Trunk Segment ◽  
The Impact

When defining trunk body segment parameters, such as segment length, mass, center of mass location, and radius of gyration, it is necessary to understand and define consistent, anatomically relevant segment boundaries. In addition to the differences in reported trunk parameters due to different data collection and analysis methods (such as cadaver studies and imaging methods), many previous publications have also used differing definitions of the trunk segment. The objective of this study was to determine the effect of differences in trunk segment definitions and obesity on the calculated mass, center of mass, and radius of gyration using dual-energy X-ray absorptiometry anthropometry calculations. Twenty-three participants were recruited in normal weight and morbidly obese body mass index categories. A frontal plane dual-energy X-ray absorptiometry scan was taken of each participant, and 3 trunk segment delineations used by Chambers, de Leva, and Zatsiorsky were used to calculate the trunk parameters. The results showed statistically significant effects of segmentation definition and obesity on the trunk parameters calculated. Because of the potential impacts on static modeling and inverse dynamics calculations, it is important to determine which trunk segmentations are most appropriate for specific applications and to account for the impact of obesity within individuals.

scholarly journals Analytical construction of the projectile motion trajectory in midair

MOMENTO ◽  
2021 ◽  
pp. 79-96
Author(s):  
Peter Chudinov ◽  
Vladimir Eltyshev ◽  
Yuri Barykin
Keyword(s):  
Analytical Solutions ◽  
Initial Conditions ◽  
Resistance Force ◽  
Tennis Ball ◽  
Projectile Motion ◽  
Classic Problem ◽  
Analytical Construction ◽  
Air Resistance ◽  
Wide Range ◽  
Large Period

A classic problem of the motion of a projectile thrown at an angle to the horizon is studied. Air resistance force is taken into account with the use of the quadratic resistance law. An analytic approach is mainly applied for the investigation. Equations of the projectile motion are solved analytically for an arbitrarily large period of time. The constructed analytical solutions are universal, that is, they can be used for any initial conditions of throwing. As a limit case of motion, the vertical asymptote formula is obtained.  The value of the vertical asymptote is calculated directly from the initial conditions of motion. There is no need to study the problem numerically. The found analytical solutions are highly accurate over a wide range of parameters. The motion of a baseball, a tennis ball, and a shuttlecock of badminton are presented as examples.

scholarly journals METHOD FOR DETERMINING THE HUMAN BODY-MASS CENTER

2019 ◽  
Vol 17 (Suppl. 2) ◽  
pp. 1-3
Author(s):  
A. Atanasov
Keyword(s):  
Body Mass ◽  
Human Body ◽  
Center Of Mass ◽  
Mass Center ◽  
Biomedical Sciences

It is described method for determining the center of the equal torques and the center of mass of the human body. The proposed method can be applied in the field of biomechanics of the human body, physiotherapy, dietetics, anatomy and in various fields of biomedical sciences.

COMPUTATIONAL AND EXPERIMENTAL STUDY OF THE FALLING LOAD TEST OF HIGH-STRENGTH PIPE STEEL X100 (K80)

2021 ◽  
Vol 83 (3) ◽  
pp. 354-368
Author(s):  
A.I. Abakumov ◽  
I.I. Safronov ◽  
A.S. Smirnov ◽  
A.B. Arabey ◽  
T.S. Esiev ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Ductile Fracture ◽  
Pipe Steel ◽  
Load Test ◽  
Resistance Force ◽  
Drop Weight ◽  
Propagation Law ◽  
Movement Distance ◽  
Sample Resistance

The behavior of samples of the promising pipe steel X100 under dynamic three-point bending is studied. This steel is compared with steel X80 currently used in the gas transmission pipeline engineering. Experimental and calculated mechanical characteristics were obtained for pipe steel X100 produced by JSC “VMZ” using data of the standard tests for laboratory samples and drop-weight tests (DWT). Steel X100 demonstrates higher strength indexes in comparison with steel X80, however, it has lower indexes of plasticity and ductile fracture resistance. High-speed video-recording of the crack propagation in a sample of steel X100 was performed in the drop-weight test. In combination with the sample resistance force dependence on the drop-weight movement distance, such testing provided much more information for studying the metal resistance to ductile fracture and allowed revealing the crack propagation law, estimating the specific dissipation energy during the crack propagation, and verifying the computational model used in DWT. Parameters of the X100 steel strain and fracture model were calibrated. The numerical simulation of the behavior of the X100 steel samples in tests at room temperature was performed. Simulation results satisfactorily agree with data of the tests with regard to such parameters as: the sample resistance force dependence as a function of the drop-weight movement distance; the striker work; strained foils, and macrogeometry of fractures in the tested sample. This results may be used for the development of requirements and conditions of using equipped DWT, as well as for the numerical simulation of full-scale tests of pipes made of steel X100 to predict the pipeline resistance to a propagating ductile crack.

System of metrological assurance of traceability of measurements of mass geometry characteristics

2020 ◽  
pp. 28-34
Author(s):  
O. V. Dovydenko ◽  
A. I. Samoylenko ◽  
V. V. Petronevich
Keyword(s):  
Center Of Mass ◽  
Mass Center ◽  
Moments Of Inertia ◽  
Technical Requirements ◽  
Type Approval ◽  
Direct Measurements ◽  
Verification Methods ◽  
Reference Measure ◽  
Primary Standards ◽  
The Mathematical Model

A system of metrological support is proposed that allows testing for type approval, verification and calibration of stands for measuring mass, coordinates of mass center and moments of inertia. The mathematical model of a special standard has been developed. It is based on the analytical principles for the determination of the mass center coordinates and inertia moments of homogeneous bodies with a regular geometric shape. The standard consists of a set of modules and fasteners of a special shape. Each module is a reference measure of both mass, center of mass coordinates, and moments of inertia, and can be used either separately or in a set with other modules. A scheme for transferring units of values from state primary standards of mass and length to stands using special standards has been developed. A method for calibration of special standards has been developed. It includes indirect measurements of the coordinates of the center of mass and moments of inertia based on the results of direct measurements of the mass and geometric dimensions of the standard modules’ elements, as well as measurements of the form deviations and deviations of position of the standard modules’ surfaces and static balancing of the standard. Technical requirements for special standards have been developed to minimize methodological measurement uncertainties when reproducing units of values by the standard. A line of special standards was created, their certification and approval in Rosstandart was carried out. Stand verification methods using special standards have been developed and approved. The type approval of two stands was carried out using special standards. The decision to grant a patent for the invention “Method for determining the error of the stand for measuring the characteristics of the mass geometry of products and a device for its implementation” was received.

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