scholarly journals Module-based kinetostatic analysis and optimization of a modular reconfigurable robot

2021 ◽  
Author(s):  
Richard P. Mohamed
Keyword(s):  
Cross Section ◽  
Direct Method ◽  
Element Model ◽  
Computational Method ◽  
Flexibility Analysis ◽  
Reconfigurable Robots ◽  
Simple Connectivity ◽  
Reconfigurable Robot ◽  
Kinetostatic Model ◽  
A Direct Method

n this thesis, a newly developed kinetostatic model for modular reconfigurable robots (MRRs) is presented. First, a kinetmatic computational method was created to allow for simple connectivity between modules which included the possibilities of angular offsets. Then, a flexibility analysis was performed to determine the static and dynamic flexibility of link and join modules and the regions of flexibility were plotted to determine exactly which of the components can be considered flexible or rigid, depending on their sizes. Afterwards, the kinetostatic model was developed and compared to a finite element model and results give essentially the same tip deflections between the two models. This kinetostatic model was then used to determine the maximum allowable payload and maximum deflection position for a given MRR. Additionally, a direct method was created to determine the cross section properties of all modules in a given MRR for a given payload and maximum desirable tip deflection.

scholarly journals Module-based kinetostatic analysis and optimization of a modular reconfigurable robot

2021 ◽  
Author(s):  
Richard P. Mohamed
Keyword(s):  
Cross Section ◽  
Direct Method ◽  
Element Model ◽  
Computational Method ◽  
Flexibility Analysis ◽  
Reconfigurable Robots ◽  
Simple Connectivity ◽  
Reconfigurable Robot ◽  
Kinetostatic Model ◽  
A Direct Method

n this thesis, a newly developed kinetostatic model for modular reconfigurable robots (MRRs) is presented. First, a kinetmatic computational method was created to allow for simple connectivity between modules which included the possibilities of angular offsets. Then, a flexibility analysis was performed to determine the static and dynamic flexibility of link and join modules and the regions of flexibility were plotted to determine exactly which of the components can be considered flexible or rigid, depending on their sizes. Afterwards, the kinetostatic model was developed and compared to a finite element model and results give essentially the same tip deflections between the two models. This kinetostatic model was then used to determine the maximum allowable payload and maximum deflection position for a given MRR. Additionally, a direct method was created to determine the cross section properties of all modules in a given MRR for a given payload and maximum desirable tip deflection.

USE OF SPATIOTEMPORAL DIAGRAMS TO CHARACTERIZE A SILO DISCHARGING PROCESS

2013 ◽  
Vol 37 (1) ◽  
pp. 53-70
Author(s):  
Blaise Nsom ◽  
Noureddine Latrache
Keyword(s):  
Cross Section ◽  
Flow Rate ◽  
Mechanical Characterization ◽  
Direct Method ◽  
Rectangular Cross Section ◽  
Small Scale ◽  
Flat Bottom ◽  
Shear Box ◽  
A Direct Method

To get a better knowledge of discharging flows of ensiled granular materials, a small scale silo was designed and built. It is equipped with a flat bottom and it has a rectangular cross section. Moreover, it is entirely transparent for image processing purpose. First of all, a physical and mechanical characterization of wood granules (inert materials) was performed using a shear box testing. Then, silo emptying flows were generated. Flow regimes and flow rate were determined using spatiotemporal diagrams extracted from images of the free surface of the ensiled material. The same method was then used to measure the flow rate of discharging flows of soya, colza and rye seeds which were characterized in a previous study. For each material studied, the flow rate measured with this non intrusive method was successfully compared with a direct method consisting in weighing a volume of grains discharged during a unit time and with Berveloo’s formula.

A direct measurement of the thermal neutron conversion ratio of natural uranium

1969 ◽  
Vol 47 (12) ◽  
pp. 1317-1325 ◽  
Author(s):  
C. B. Bigham ◽  
R. W. Durham ◽  
J. Ungrin
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Direct Method ◽  
Natural Uranium ◽  
Conversion Ratio ◽  
Absorption Cross ◽  
A Direct Method ◽  
Good Agreement

A direct method for measuring the thermal neutron conversion ratio of natural uranium (capture in 238U)/(destruction of 235U), gives 0.5655 ± 0.0025 (20 °C Maxwellian) in good agreement with 0.565 ± 0.009 from the separately measured cross sections. The corresponding value for the 2200 m/s absorption cross section of 238U is 2.721 ± 0.016 b. The method is based on the use of a sample of 243Am, which α-decays to 239Np, for correlating the efficiencies of the fission counter and γ counter used to measure the number of fissions and the amount of 239Np produced during an irradiation of a natural uranium sample.

The Numerical Analysis of Contaminant Migration from Sanitary Landfill Sites

1977 ◽  
Vol 12 (1) ◽  
pp. 233-255
Author(s):  
J.F. Sykes ◽  
A.J. Crutcher
Keyword(s):  
Contaminant Transport ◽  
Cross Section ◽  
Element Model ◽  
Sanitary Landfill ◽  
Saturated Porous Media ◽  
Two Dimensional ◽  
Contaminant Migration ◽  
Southern Ontario ◽  
Galerkin Finite Element ◽  
Chloride Concentrations

Abstract A two-dimensional Galerkin finite element model for flow and contaminant transport in variably saturated porous media is used to analyze the transport of chlorides from a sanitary landfill located in Southern Ontario. A representative cross-section is selected for the analysis. Predicted chloride concentrations are presented for the cross section at various horizon years.

scholarly journals Plastic waste to fuels by hydrocracking at mild conditions

2021 ◽  
Vol 7 (17) ◽  
pp. eabf8283
Author(s):  
Sibao Liu ◽  
Pavel A. Kots ◽  
Brandon C. Vance ◽  
Andrew Danielson ◽  
Dionisios G. Vlachos
Keyword(s):  
Direct Method ◽  
Acid Sites ◽  
Liquid Fuels ◽  
High Yield ◽  
Tandem Catalysis ◽  
Hy Zeolite ◽  
Environmental Threat ◽  
Single Use ◽  
Initial Activation ◽  
A Direct Method

Single-use plastics impose an enormous environmental threat, but their recycling, especially of polyolefins, has been proven challenging. We report a direct method to selectively convert polyolefins to branched, liquid fuels including diesel, jet, and gasoline-range hydrocarbons, with high yield up to 85% over Pt/WO3/ZrO2 and HY zeolite in hydrogen at temperatures as low as 225°C. The process proceeds via tandem catalysis with initial activation of the polymer primarily over Pt, with subsequent cracking over the acid sites of WO3/ZrO2 and HY zeolite, isomerization over WO3/ZrO2 sites, and hydrogenation of olefin intermediates over Pt. The process can be tuned to convert different common plastic wastes, including low- and high-density polyethylene, polypropylene, polystyrene, everyday polyethylene bottles and bags, and composite plastics to desirable fuels and light lubricants.

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