Advanced Numerical Modeling of Nonlinear Elastic Cable With Recovery Characteristics

2017 ◽  
Author(s):  
Sung-Hyun Choi ◽  
Kyoung-Su Park
Keyword(s):  
Numerical Modeling ◽  
Steel Wire ◽  
High Sensitivity ◽  
Industrial Applications ◽  
Parallel Robots ◽  
Burger Model ◽  
Lower Weight ◽  
Nonlinear Elastic ◽  
Good Agreement

Cable driven parallel robots (CDPRs) have many advantages such as low inertia and large workspace. These advantages lead to the industrial applications. CDPRs mainly use Dyneema polymer cable for more high sensitivity because it has advantage of the lower weight than steel wire. However, the polymer cable is continuously deformed when actuating the CDPR because of the elasto-plastic cable characteristics such as recovery. In this paper, numerical cable recovery was proposed using the modified burger model. Finally, the models were simulated and compared with the experimental profiles. As the result, the simulations are good agreement with the experimental profiles.

Advanced Numerical Modeling of Nonlinear Elastic Cable With Permanent Stretch Using Cable Driven Parallel Robot

2017 ◽  
Author(s):  
Sung-Hyun Choi ◽  
Kyoung-Su Park
Keyword(s):  
Numerical Modeling ◽  
Steel Wire ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Cable Model ◽  
Lower Weight ◽  
Simulation Results ◽  
Nonlinear Elastic ◽  
Good Agreement ◽  
Elastic Characteristics

Since cable driven parallel robots (CDPRs) have many advantages, they have been used in many industrial fields. Fully constrained CDPRs mainly use Dyneema polyethylene because it has advantage of the lower weight than steel wire. However, the polyethylene cable has complex elastic characteristics (e.g. permanent stretch and hysteresis). In this paper, the advanced numerical modeling of nonlinear elastic cable with permanent stretch using cable driven parallel robot was derived and simulated for various cable condition. Based on the advanced numerical nonlinear cable model, the simulation was carried out under the various cable lengths and tensions. Compared to the experimental results, the simulation results are good agreement with the experimental data.

Numerical Modeling of Evolution of Boundary Between Incompressible Gas and Liquid in Two-Dimensional Region

2006 ◽  
Vol 4 ◽  
pp. 224-236
Author(s):  
A.S. Topolnikov
Keyword(s):  
Numerical Modeling ◽  
Interphase Boundary ◽  
Incompressible Liquid ◽  
Stokes Equations ◽  
Numerical Code ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Incompressible Media ◽  
Good Agreement

The paper is devoted to numerical modeling of Navier–Stokes equations for incompressible media in the case, when there exist gas and liquid inside the rectangular calculation region, which are separated by interphase boundary. The set of equations for incompressible liquid accounting for viscous, gravitational and surface (capillary) forces is solved by finite-difference scheme on the spaced grid, for description of interphase boundary the ideology of Level Set Method is used. By developed numerical code the set of hydrodynamic problems is solved, which describe the motion of two-phase incompressible media with interphase boundary. As a result of numerical simulation the solutions are obtained, which are in good agreement with existing analytical and experimental solutions.

scholarly journals Hybrid POF/VLC Links Based on a Single LED for Indoor Communications

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 254
Author(s):  
Juan Andrés Apolo ◽  
Beatriz Ortega ◽  
Vicenç Almenar
Keyword(s):  
Optical Power ◽  
Industrial Applications ◽  
Free Space Optics ◽  
Polymer Optical Fiber ◽  
Hybrid Fiber ◽  
Modulation Formats ◽  
Space Optics ◽  
Indoor Communications ◽  
Power Measurements ◽  
Good Agreement

A hybrid fiber/wireless link based on a single visible LED and free of opto-electronic intermediate conversion stages has been demonstrated for indoor communications. This paper shows the main guidelines for proper coupling in fiber/air/detector interfaces. Experimental demonstration has validated the design results with very good agreement between geometrical optics simulation and received optical power measurements. Different signal bandwidths and modulation formats, i.e., QPSK, 16-QAM, and 64-QAM, have been transmitted over 1.5 m polymer optical fiber (POF) and 1.5 m free-space optics (FSO). Throughputs up to 294 Mb/s using a 64-QAM signal have been demonstrated using a commercial LED, which paves the way for massive deployment in industrial applications.

scholarly journals High Sensitivity Continuous Monitoring of Chloroform Gas by Using Wavelength Modulation Photoacoustic Spectroscopy in the Near-Infrared Range

2021 ◽  
Vol 11 (15) ◽  
pp. 6992
Author(s):  
Tie Zhang ◽  
Yuxin Xing ◽  
Gaoxuan Wang ◽  
Sailing He
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Continuous Monitoring ◽  
Near Infrared ◽  
Resonant Cavity ◽  
High Sensitivity ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Infrared Range ◽  
Wavelength Modulation ◽  
Linear Coefficient

An optical system for gaseous chloroform (CHCl3) detection based on wavelength modulation photoacoustic spectroscopy (WMPAS) is proposed for the first time by using a distributed feedback (DFB) laser with a center wavelength of 1683 nm where chloroform has strong and complex absorption peaks. The WMPAS sensor developed possesses the advantages of having a simple structure, high-sensitivity, and direct measurement. A resonant cavity made of stainless steel with a resonant frequency of 6390 Hz was utilized, and eight microphones were located at the middle of the resonator at uniform intervals to collect the sound signal. All of the devices were integrated into an instrument box for practical applications. The performance of the WMPAS sensor was experimentally demonstrated with the measurement of different concentrations of chloroform from 63 to 625 ppm. A linear coefficient R2 of 0.999 and a detection sensitivity of 0.28 ppm with a time period of 20 s were achieved at room temperature (around 20 °C) and atmosphere pressure. Long-time continuous monitoring for a fixed concentration of chloroform gas was carried out to demonstrate the excellent stability of the system. The performance of the system shows great practical value for the detection of chloroform gas in industrial applications.

scholarly journals EVALUATION OF ELEVEN IMMUNOCHROMATOGRAPHIC ASSAYS FOR SARS-CoV-2 DETECTION: INVESTIGATING DENGUE CROSS-REACTION

2020 ◽  
Author(s):  
Beatriz Araujo Oliveira ◽  
Lea Campos de Oliveira ◽  
Franciane Mendes de Oliveira ◽  
Geovana Maria Pereira ◽  
Regina Maia de Souza ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Diagnostic Techniques ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
List Type ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Good Agreement

AbstractBackgroundCOVID-19 disease (Coronavirus disease 2019) caused by SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) is widespread worldwide, affecting more than 11 million people globally (July 6th, 2020). Diagnostic techniques have been studied in order to contain the pandemic. Immunochromatographic (IC) assays are feasible and low cost alternative for monitoring the spread of COVID-19 in the population.MethodsHere we evaluate the sensitivity and specificity of eleven different immunochromatographic tests in 98 serum samples from confirmed cases of COVID-19 through RT-PCR and 100 negative serum samples from blood donors collected in February 2019. Considering the endemic situation of Dengue in Brazil, we also evaluated the cross-reactivity with Dengue using 20 serum samples from patients with confirmed diagnosis for Dengue collected in early 2019 through four different tests.ResultsOur results demonstrated agreement between immunochromatographic assays and RT-PCR, especially after 10 days since the onset of symptoms. The evaluation of IgG and IgM antibodies combined demonstrated a strong level of agreement (0.85) of IC assays and RT-PCR. It was observed cross-reactivity between Dengue and COVID-19 using four different IC assays for COVID-19 diagnosis. The specificity of IC assays to detected COVID-19 IgM antibodies using Dengue serum samples varied from 80% to 85%; the specificity of IgG detection was 100% and total antibody was 95%.ConclusionsWe found high sensitivity, specificity and good agreement of IC assays, especially after 10 days onset of symptoms. However, we detected cross-reactivity between Dengue and COVID-19 mainly with IgM antibodies demonstrating the need for better studies about diagnostic techniques for these diseases.HighlightsImmunochromatographic assays demonstrated high sensitivity and specificity and good agreement with the gold-standard RT-PCR;Increase in sensitivity and specificity of assays using samples collected after the 10th day of symptoms;Cross-reaction with Dengue serology in evaluation of IgM.

scholarly journals IDENTIFICATION AND VERIFICATION OF MATERIAL FUNCTIONS OF THE CREEP MODEL UNDER THERMAL RADIATION EFFECTS FOR AUSTENITIC STEEL 1X18H10T

2020 ◽  
Vol 82 (1) ◽  
pp. 89-99
Author(s):  
V.A. Gorokhov
Keyword(s):  
Experimental Data ◽  
Numerical Modeling ◽  
Creep Rate ◽  
Thermal Radiation ◽  
Neutron Irradiation ◽  
Radiation Effects ◽  
Thermal Creep ◽  
Creep Model ◽  
Material Functions ◽  
Good Agreement

In the present paper, on the basis of the information available in the scientific literature on the thermal creep rate of 1X18H10T austenitic steel under neutron irradiation conditions, the material functions of the thermal creep model implemented and verified in the framework of the certified software for numerical modeling of structural deformation under thermal and thermal radiation effects of UPAKS software are obtained and verified. The list of identifiable material functions of the thermal creep model includes: a function that characterizes the initial creep strain rate, referred to a unit stress level at a given temperature level and stress parameter; the radius of the creep surface, which is a function of temperature; the hardening function, characterizing the change in the initial creep rate from the hardening parameter at a given temperature; a function that takes into account the effect of a fast neutron flux on the creep rate at a given temperature. Using an analytical approximation of experimental data describing the rate of thermal creep of steels under neutron irradiation depending on the stresses, temperature, and flux of fast neutrons, we obtained relations for determining the values of all the functions of the thermal creep model. The value of the radius of the creep surface for a fixed temperature was determined from the condition that the creep deformation for a selected period of time and the neutron flux accumulated during this time will not exceed 0.2%. Using the UPAKS software, the creep model and the obtained material functions implemented in them, numerical simulation of the deformation of 1X18H10T steel under conditions of prolonged thermal load and neutron irradiation was performed. The results of numerical modeling are in good agreement with the analytical dependences that describe the creep of a given material under uniaxial SSS. A numerical creep simulation was also carried out under the assumption of the absence of neutron irradiation. As in the case of neutron irradiation, good agreement is obtained between the calculated and experimental data.

scholarly journals Comparison of GPM Core Observatory and Ground-Based Radar Retrieval of Mass-Weighted Mean Raindrop Diameter at Midlatitude

2018 ◽  
Vol 19 (10) ◽  
pp. 1583-1598 ◽  
Author(s):  
Leo Pio D’Adderio ◽  
Gianfranco Vulpiani ◽  
Federico Porcù ◽  
Ali Tokay ◽  
Robert Meneghini
Keyword(s):  
High Sensitivity ◽  
Sensitivity Study ◽  
Three Dimensions ◽  
Convective Precipitation ◽  
Precipitation Pattern ◽  
Dual Frequency ◽  
Weighted Mean ◽  
Raindrop Size Distribution ◽  
Two Parameters ◽  
Good Agreement

Abstract One of the main goals of the National Aeronautics and Space Administration (NASA) Global Precipitation Measurement (GPM) mission is to retrieve parameters of the raindrop size distribution (DSD) globally. As a standard product of the Dual-Frequency Precipitation Radar (DPR) on board the GPM Core Observatory satellite, the mass-weighted mean diameter Dm and the normalized intercept parameter Nw are estimated in three dimensions at the resolution of the radar. These are two parameters of the three-parameter gamma model DSD adopted by the GPM algorithms. This study investigates the accuracy of the Dm retrieval through a comparative study of C-band ground radars (GRs) and GPM products over Italy. The reliability of the ground reference is tested by using two different approaches to estimate Dm. The results show good agreement between the ground-based and spaceborne-derived Dm, with an absolute bias being generally lower than 0.5 mm over land in stratiform precipitation for the DPR algorithm and the combined DPR–GMI algorithm. For the DPR–GMI algorithm, the good agreement extends to convective precipitation as well. Estimates of Dm from the DPR high-sensitivity (HS) Ka-band data show slightly worse results. A sensitivity study indicates that the accuracy of the Dm estimation is independent of the height above surface (not shown) and the distance from the ground radar. On the other hand, a nonuniform precipitation pattern (interpreted both as high variability and as a patchy spatial distribution) within the DPR footprint is usually associated with a significant error in the DPR-derived estimate of Dm.

Consecutive determination of softwood kraft lignin structure and molar mass from NMR measurements

Holzforschung ◽  
2017 ◽  
Vol 71 (7-8) ◽  
pp. 563-570 ◽  
Author(s):  
Jerk Rönnols ◽  
Anna Jacobs ◽  
Fredrik Aldaeus
Keyword(s):  
Molar Mass ◽  
Industrial Applications ◽  
Size Exclusion ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Exclusion Chromatography ◽  
Pfg Nmr ◽  
Softwood Kraft Lignin ◽  
Good Agreement

Abstract The general molecular properties and in particular, the molar mass of lignin are of central importance for industrial applications, as these data govern important thermal and mechanical characteristics. The focus of the present paper is pulsed field gradient-nuclear magnetic resonance (PFG-NMR), which is suitable for determination of lignins’ weight-average molar mass, based on diffusion constants. The method is calibrated by lignin fractions characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). It could be demonstrated on a set of softwood kraft lignins that the PFG-NMR approach gives results in very good agreement with those obtained using conventional size exclusion chromatography (SEC).

NEW METHOD OF IMPULSIVE ELECTROMAGNETIC LOGGING SOUNDING: MAPPING OF THE BAZHENOVSKAYA FORMATION FROM JURASSIC RESERVOIRS PENETRATED BY INCLINED-HORIZONTAL WELLS

2021 ◽  
pp. 31-39
Author(s):  
M. I. Epov ◽  
◽  
V. N. Glinskikh ◽  
M. N. Nikitenko ◽  
K. V. Sukhorukova ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Modeling ◽  
Middle Jurassic ◽  
High Sensitivity ◽  
Horizontal Wells ◽  
New Method ◽  
Electromagnetic Sounding ◽  
Bazhenov Formation ◽  
Spatial Locations

The work is devoted to the substantiation of new geophysical technology for mapping the Bazhenovskaya Formation based on an impulsive electromagnetic sounding from wells. Theoretically shown the possibility of its application to study the formation from highly inclined and subhorizontal wells drilled in the Upper and Middle Jurassic formations. Numerical modeling of the signals in realistic geoelectric models of the Bazhenov Formation with real well trajectories is carried out on the example of the East Surgut field. The calculations have established that the determination of spatial locations of the top and bottom of the beds is possible when using different-length sondes. Zones of high sensitivity of the full magnetic field matrix to the boundaries with a sufficient signal level at considerable distance, even with a small sonde length, are determined. It is theoretically established that pulsed sounding of the Bazhenov Formation from the Upper and Middle Jurassic reservoirs is feasible for both mapping the boundaries of the formation and tracing its lateral variability.

scholarly journals Modelling the Characteristics of Ring-Shaped Magnetoelastic Force Sensor in Mohri’s Configuration

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 266 ◽  
Author(s):  
Anna Ostaszewska-Liżewska ◽  
Roman Szewczyk ◽  
Peter Raback ◽  
Mika Malinen
Keyword(s):  
Experimental Data ◽  
High Sensitivity ◽  
Force Sensor ◽  
Inhomogeneous Distribution ◽  
The Finite Element Method ◽  
The Core ◽  
Magnetoelastic Effect ◽  
Proposed Model ◽  
Distribution Of Stresses ◽  
Good Agreement

Magnetoelastic force sensors exhibit high sensitivity and robustness. One commonly used configuration of force sensor with a ring-shaped core was presented by Mohri at al. In this configuration force is applied in the direction of a diameter of the core. However, due to inhomogeneous distribution of stresses, model of such sensor has not been presented yet. This paper is filling the gap presenting a new method of modelling the magnetoelastic effect, which is especially suitable for the finite element method. The presented implementation of proposed model is in good agreement with experimental data and creates new possibilities of modelling other devices utilizing magnetoelastic effect.

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