scholarly journals Modeling of a Microscale Surface Using NURBS Technique

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 775
Author(s):  
Jeongki Jang ◽  
Kyungmok Kim
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Surface Profile ◽  
Surface Model ◽  
Nurbs Surface ◽  
Profile Data ◽  
B Spline ◽  
Surface Interpolation ◽  
Interpolation Technique

This article describes microscale surface modeling using the Non-Uniform Rational B-Spline (NURBS) surface interpolation technique. A three-dimensional surface model was generated on the basis of measured surface profile data. To validate this model, three brass specimens having different roughness values were used. Direct comparison between measured profiles and the curves modeled with NURBS was employed. It was identified that the proposed method allows the generation of microscale models similar to actual surfaces. Finally, a method to extract the Bearing Area Curve (BAC) from a 3D model was detailed. The proposed modeling will be useful for the characterization of bearing capacity of the surface and for contact analysis.

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

INSIM-FPT-3D: A Data-Driven Model for History Matching, Water-Breakthrough Prediction and Well-Connectivity Characterization in Three-Dimensional Reservoirs

2021 ◽  
Author(s):  
Hui Zhao ◽  
Wei Liu ◽  
Xiang Rao ◽  
Guanglong Sheng ◽  
Huazhou Andy Li ◽  
...  
Keyword(s):  
Simulation Model ◽  
History Matching ◽  
3D Model ◽  
Reference Model ◽  
Three Dimensional ◽  
Data Driven ◽  
Series Data ◽  
Reference Models ◽  
Water Breakthrough

Abstract The data-driven interwell simulation model (INSIM) has been recognized as an effective tool for history matching and interwell-connectivity characterization of waterflooding reservoirs. INSIM-FT-3D (FT: front tracking) was recently developed to upgrade the applicationdimension of INSIM series data-driven models from two-dimensional (2D) to three-dimensional (3D). However, INSIM-FT-3D cannot accurately infer the dynamic change of well-connectivity and predict well's bottom-hole pressure (BHP). The main purpose of this study intends to expand the capability of INSIM-FT-3D to empower for the assimilation of BHPs, the reliable prediction of water breakthrough and the characterization of dynamic interwell-connectivities. The default setting of well index (WI) in INSIM-FT-3D based on Peaceman's equation does not yield accurate BHP estimates. We derive a WI that can honor the BHPs of a reference model composed of a set of 1D connections. When history matching BHPs of a 3D reservoir, we show that the derived WI is a better initial guess than that obtained from Peaceman's equation. We also develop a flow-path-tracking (FPT) algorithm to calculate the dynamic interwell properties (allocation factors and pore volumes (PVs)). Besides, we discuss the relationship between the INSIM-family methods and the traditional grid-based methods, which indicates that the INSIM-family methods can calculate the transmissibility of the connection between coarse-scale cells in a more accurate manner. As an improvement of INSIM-FT-3D, the newly proposed data-driven model is denoted as INSIM-FPT-3D. To verify the correctness of the derived WI, we present a 1D problem and a T-shaped synthetic reservoir simulation model as the reference models. BHPs and oil production rates are obtained as the observed data by running these two reference models with total injection/production-rate controls. An INSIM-FPT-3D model is created by specifying the transmissibilities and PVs that are the same as those in the reference model. By applying the derived WIs in INSIM-FPT-3D, the resulting BHPs and oil rates obtained agree well with the reference model without further model calibration. Applying INSIM-FPT-3D to a synthetic multi-layered reservoir shows that we obtain a reasonable match of both BHPs and oil rates with INSIM-FPT-3D. Compared with the FrontSim model, the INSIM-FPT-3D model after history matching is shown to match the dynamic PVs from FrontSim reasonably well and can correctly predict the timing of water breakthrough. By allowing for the assimilation of BHP data, we enable INSIM-FPT-3D to history match a green field with limited production history and forecast the timing of water breakthrough. The improved INSIM-FPT-3D leads to more accurate characterization of the interwell connectivities.

Shape Optimization of a Camoid Follower Surface

2008 ◽  
Author(s):  
Karim A. Aguib ◽  
Keith A. Hekman ◽  
Ashraf O. Nassef
Keyword(s):  
Genetic Algorithms ◽  
Shape Optimization ◽  
Three Dimensional ◽  
Characteristic Surface ◽  
Design Constraints ◽  
B Splines ◽  
Surface Interpolation ◽  
Specific Objective ◽  
Interpolation Technique ◽  
Real Coded Genetic Algorithms

Camoids are three dimensional cams that can produce more complex follower output than plain disc cams. A camoid follower motion is described by a surface rather than a curve. The camoid profile can be directly synthesized once the follower surface is fully described. To define a camoid follower motion surface it is required that the surface pass by all predefined constraints. Constraints can be follower position, velocity and acceleration. These design constraints are scattered all along the camoid follower surface. Hence a fitting technique is needed to satisfy these constraints which include position and its derivatives (velocity and acceleration). Furthermore if the fitting function can be of a parametric nature, then it would be possible to optimize the follower surface to obtain better performance according to a specific objective. Previous research has established a method to fit camoid follower surface positions, but did not tackle the satisfaction of derivative constraints. This paper presents a method for defining a camoid follower characteristic surface B-Splines on two steps first synthesizing the sectional cam curves then using a surface interpolation technique to generate the follower characteristic surface. The fitting technique is parametric in nature which allows for its optimization. Real coded Genetic algorithms are used to optimize the parameters of the surface to meet a specified objective function. A demonstration problem to illustrate the suggested methodology is presented.

scholarly journals A Reconstruction Algorithm for Blade Surface Based on Less Measured Points

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jia Liu ◽  
Ji Zhao ◽  
Xu Yang ◽  
Jiming Liu ◽  
Xingtian Qu ◽  
...  
Keyword(s):  
Reconstruction Algorithm ◽  
Surface Model ◽  
Machining Accuracy ◽  
Blade Surface ◽  
B Spline ◽  
Design Concepts ◽  
Surface Interpolation ◽  
Spline Surface ◽  
Machining Allowance ◽  
Curvature Continuity

A reconstruction algorithm for blade surface from less measured points of section curves is given based on B-spline surface interpolation. The less measured points are divided into different segments by the key geometric points and throat points which are defined according to design concepts. The segmentations are performed by different fitting algorithms with consideration of curvature continuity as their boundary condition to avoid flow disturbance. Finally, a high-quality reconstruction surface model is obtained by using the B-spline curve meshes constructed by paired points. The advantage of this algorithm is the simplicity and effectivity reconstruction of blade surface to ensure the aerodynamic performance. Moreover, the obtained paired points can be regarded as measured points to measure and reconstruct the blade surface directly. Experimental results show that the reconstruction blade surface is suitable for precisely representing blade, evaluating machining accuracy, and analyzing machining allowance.

scholarly journals Variation of physiological parameters in juvenile treetops of Eucalyptus tereticornis from a three-dimensional perspective

2018 ◽  
Vol 2 (23) ◽  
Author(s):  
Juan Carlos Valverde ◽  
Dagoberto Arias
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Physiological Parameters ◽  
Eucalyptus Tereticornis ◽  
Physiological Variables

We analyzed the characterization of physiological variables in treetops of E. tereticornis; obtaining An of 28.6-40.6 μmol m-2s-1, E of 8.53-16.90 μmol m-2s-1, Gs of 87.47-335.16 mmol m-2s-1, Pp of 65-320 kPa and SPAD of 20.5-38.40; The analysis showed that external and medium branch in higher treetop obtained physiological behaviors significantly lower than the rest of treetop, because they are growing and leaves have not yet reached their peak. Also, we found that 3D model allowed the developed model that simplified information.

Evaluation of Structural and Biomechanical Characterization of Implant for Cranial Restoration

2019 ◽  
Vol 9 (7) ◽  
pp. 898-903
Author(s):  
Fu-Hui Tsai ◽  
Han-Yi Cheng
Keyword(s):  
Finite Element ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Biomechanical Properties ◽  
Clinical Applications ◽  
Finite Element Models ◽  
Critical Factors ◽  
Circular Structure

The objective this research was to investigate the biomechanical properties of various structures and thicknesses of implants for cranial restoration. A three-dimensional (3D) printing (3DP) technique has been applied in factories for several decades, but it was only recently introduced to the dental field less than 10 years ago. The structures of pre-shaped cranial mesh implants are critical factors for clinical applications. Many previous studies used finite element models to investigate for implants, but few examined a 3D model for pre-shaped cranial mesh implants with different structures and thicknesses. 3D cranial models were reconstructed using computer tomography to simulate preshaped cranial mesh implants under physical impacts. Data indicated that the stress significantly decreased when implants with greater thicknesses were used. Moreover, the implant with a circular structure created a relatively smaller stress that was approximately 7% lower compared to the implant with a triangular structure. As described above, the results of the present study demonstrate that 3DP-Ti is a reliable material of implants for cranial restoration.

scholarly journals Molecular Cloning and Exploration of the Biochemical and Functional Analysis of Recombinant Glucose-6-Phosphate Dehydrogenase from Gluconoacetobacter diazotrophicus PAL5

2019 ◽  
Vol 20 (21) ◽  
pp. 5279 ◽  
Author(s):  
Edson Jiovany Ramírez-Nava ◽  
Daniel Ortega-Cuellar ◽  
Abigail González-Valdez ◽  
Rosa Angélica Castillo-Rodríguez ◽  
Gabriel Yaxal Ponce-Soto ◽  
...  
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Endophytic Bacterium ◽  
Pentose Phosphate ◽  
Native State ◽  
E Coli ◽  
Optimal Activity ◽  
Glucose 6 Phosphate Dehydrogenase

Gluconacetobacter diazotrophicus PAL5 (GDI) is an endophytic bacterium with potential biotechnological applications in industry and agronomy. The recent description of its complete genome and its principal metabolic enzymes suggests that glucose metabolism is accomplished through the pentose phosphate pathway (PPP); however, the enzymes participating in this pathway have not yet been characterized in detail. The objective of the present work was to clone, purify, and biochemically and physicochemically characterize glucose-6-phosphate dehydrogenase (G6PD) from GDI. The gene was cloned and expressed as a tagged protein in E. coli to be purified by affinity chromatography. The native state of the G6PD protein in the solution was found to be a tetramer with optimal activity at pH 8.8 and a temperature between 37 and 50 °C. The apparent Km values for G6P and nicotinamide adenine dinucleotide phosphate (NADP+) were 63 and 7.2 μM, respectively. Finally, from the amino acid sequence a three-dimensional (3D) model was obtained, which allowed the arrangement of the amino acids involved in the catalytic activity, which are conserved (RIDHYLGKE, GxGGDLT, and EKPxG) with those of other species, to be identified. This characterization of the enzyme could help to identify new environmental conditions for the knowledge of the plant–microorganism interactions and a better use of GDI in new technological applications.

Model Based Characterization of the Grinding Wheel Effective Topography

2008 ◽  
Vol 389-390 ◽  
pp. 258-263
Author(s):  
Niklas Kramer ◽  
C. Wangenheim
Keyword(s):  
Distribution Systems ◽  
Three Dimensional ◽  
Grinding Wheel ◽  
Surface Model ◽  
Wheel Surface ◽  
The Real ◽  
Model Based ◽  
Abrasive Grain ◽  
Developed Surface

In this paper the geometry of the grinding wheel effective topography is analyzed. Existing and newly developed abrasive grain geometry models are investigated. Further, different abrasive distribution systems are developed and the grinding wheel surface is generated. The 3D stereomicroscopy at the Scanning Electron Microscope offers the opportunity to measure a three-dimensional profile of the grinding wheel. Hence, the investigations of the real grinding wheel surface can be used as a verification of the developed surface model. Abbott-Firestone-Curves are used as a comparison of the model based topography and the real grinding wheel surface. The variation of the grain geometry and distribution offers the opportunity to adapt the simulation to the grinding wheel specification.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

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