scholarly journals Elements for the Successful Computer Simulation of Sediment Management Strategies for Reservoirs

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 714 ◽  
Author(s):  
Razieh Anari ◽  
Rollin H. Hotchkiss ◽  
Eddy Langendoen
Keyword(s):  
Computer Simulation ◽  
Management Strategies ◽  
Three Dimensional ◽  
Sediment Management ◽  
Three Dimensions ◽  
Density Currents ◽  
Local Pressure ◽  
Reservoir Sediment ◽  
Computer Codes

Computer simulation of reservoir sediment management strategies is becoming more important as worldwide water supply shrinks due to sediment deposition, while population growth continues. We identified the physical processes underlying each of the several alternatives available to transport incoming or deposited sediments downstream into receiving waters and the governing equations that describe each process. The purpose of this paper is to understand how physical characteristics of reservoir sediment management can be simulated with available computer codes. We described commonly available computer codes and their abilities to solve the appropriate equations in one, two, or three dimensions. The results revealed that one dimensional models are most appropriate for long-term simulations of the evolving reservoir bottom profile, while two or three dimensional codes are more appropriate for simulating density currents and detailed lateral movement of sediments, such as during local pressure flushing near reservoir outlets. We conclude that existing codes can successfully simulate sediment management, but because each code has limitations, they require seasoned judgment in their choice, application, and interpretation. Incorporating sediment prediction and management correctly into the planning, design, and operational phases of dam projects is essential for ensuring that the benefits of reservoir storage are sustained over the long term. The implications of our key findings are that sediment management strategies can be successfully simulated and that such simulations should be performed for our aging dams and newly proposed projects.

scholarly journals A systematic study of proto-neutron star convection in three-dimensional core-collapse supernova simulations

2020 ◽  
Vol 492 (4) ◽  
pp. 5764-5779 ◽  
Author(s):  
Hiroki Nagakura ◽  
Adam Burrows ◽  
David Radice ◽  
David Vartanyan
Keyword(s):  
Neutron Star ◽  
Systematic Study ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Tau Neutrinos ◽  
The Impact ◽  
Proto Neutron Star

ABSTRACT This paper presents the first systematic study of proto-neutron star (PNS) convection in three dimensions (3D) based on our latest numerical fornax models of core-collapse supernova (CCSN). We confirm that PNS convection commonly occurs, and then quantify the basic physical characteristics of the convection. By virtue of the large number of long-term models, the diversity of PNS convective behaviour emerges. We find that the vigour of PNS convection is not correlated with CCSN dynamics at large radii, but rather with the mass of PNS − heavier masses are associated with stronger PNS convection. We find that PNS convection boosts the luminosities of νμ, ντ, $\bar{\nu }_{\mu }$, and $\bar{\nu }_{\tau }$ neutrinos, while the impact on other species is complex due to a competition of factors. Finally, we assess the consequent impact on CCSN dynamics and the potential for PNS convection to generate pulsar magnetic fields.

scholarly journals Printing In Three Dimensions

2001 ◽  
Vol 123 (05) ◽  
pp. 58-60 ◽  
Author(s):  
Jean Thilmany
Keyword(s):  
Three Dimensional ◽  
Physical Models ◽  
Three Dimensions ◽  
Digital Archive ◽  
3D Printer ◽  
Vehicle Engineering ◽  
3D Cad ◽  
Hard Time ◽  
Entire Vehicle

This article discusses that a starch printer, commonly referred to as a three-dimensional printer, serves as a way to make physical models from 3D CAD files. The rapid engineering and 3D printing methods are frequently used in conjunction with a host of compatible technologies, notably a scanning technology that brings physical objects—including items produced by a 3D printer—back into the digital realm. Engineers make use of this form of scanning technology to digitize a complex item that they would have a hard time reverse engineering any other way. Others might use it to digitize 3D artwork such as sculptures to capture a long-term, digital archive of important cultural artifacts. Rapid prototyping at DaimlerChrysler takes place in the vehicle engineering operations mock-up department, among other places. The group builds physical models of parts for the engineers who designed them. Models might range from an individual part to a full-scale mock-up of the entire vehicle.

scholarly journals The Development of a Three-Dimensional Material Point Method Computer Simulation Algorithm for Bullet Impact Studies

2010 ◽  
Vol 9 (2 and 3) ◽  
Author(s):  
M Connolly ◽  
E Maldonado ◽  
M Roth
Keyword(s):  
Computer Simulation ◽  
Biological Systems ◽  
Three Dimensional ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Three Dimensions ◽  
Simulation Algorithm ◽  
Two Dimensional ◽  
Impact Studies

The two-dimensional Material Point Method (MPM) algorithm outlined by Chen and Brannon has been extended to three dimensions. The development of the code is discussed as well as applications for simulating bullet impact on biological and non-biological systems.

scholarly journals Current and Future Study Topics on Reservoir Sediment Management by Bypass Tunnels

2018 ◽  
Vol 13 (4) ◽  
pp. 668-676 ◽  
Author(s):  
Sohei Kobayashi ◽  
◽  
Takahiro Koshiba ◽  
Tetsuya Sumi
Keyword(s):  
Sediment Transport ◽  
Future Study ◽  
International Workshop ◽  
Sediment Management ◽  
Sediment Supply ◽  
Reservoir Sediment ◽  
Efficient Operation ◽  
Abrasion Rate ◽  
Runoff Model

Herein, we summarized the current and future study topics of sediment management using bypass tunnels based on the discussions at the Second International Workshop on Sediment Bypass Tunnels (SBTs) at Kyoto in May 2017. Although reservoir sediment management using bypass tunnels has appeared since the beginning of the 20th century in Kobe, the number of SBTs worldwide is still limited. To promote the installation of SBTs as an effective sediment management measure, it is essential to appropriately evaluate their long-term advantages economically and for the restoration of the aquatic ecosystem. An abrasion model has been developed to predict the abrasion rate of tunnels from the volume of sediment transport. Further, methods to monitor sediment transport in tunnels have advanced. With a significant amount of sediment supply by SBTs, the ecosystems in the downstream reaches of dams can be restored within a few years. A precise rainfall and runoff model for predicting the inflow hydrograph and sediment is essential for the efficient operation of dam gates and SBT (e.g., diverting minimum amount of water for sediment transport). Further studies are needed to clarify the suitable grain size for transportation through SBTs in terms of both the mitigation of tunnel abrasion and promotion of the restoration of downstream ecosystems.

Reservoir Sediment Management Strategies

2019 ◽  
pp. 195-236
Author(s):  
Kumkum Bhattacharyya ◽  
Vijay P. Singh
Keyword(s):  
Management Strategies ◽  
Sediment Management ◽  
Reservoir Sediment

Long-Term Effects of Nasoalveolar Molding on Three-Dimensional Nasal Shape in Unilateral Clefts

1999 ◽  
Vol 36 (5) ◽  
pp. 391-397 ◽  
Author(s):  
Deirdre J. Maull ◽  
Barry H. Grayson ◽  
Court B. Cutting ◽  
Larry L. Brecht ◽  
Fred L. Bookstein ◽  
...  
Keyword(s):  
New York ◽  
Medical Center ◽  
Three Dimensional ◽  
Asymmetry Index ◽  
Mirror Image ◽  
Three Dimensions ◽  
Control Group ◽  
Long Term Effects ◽  
Nasoalveolar Molding

Objective: This objective of this study was to determine the effect of presurgical nasoalveolar molding on long-term nasal shape in complete unilateral clefts. Design: The study was retrospective, and the subjects were chosen at random. Nasal casts of the subjects were scanned in three dimensions. Each nose was best fit to its mirror image, and a numerical asymmetry score was determined. Setting: All patients were treated at the Institute of Reconstructive Plastic Surgery, NYU Medical Center, New York, New York. Patients: The study subjects (n = 10) were selected from a group that had undergone presurgical nasal molding in conjunction with alveolar molding. The control subjects (n = 10) were selected from a group that had undergone presurgical alveolar molding alone. Interventions: All subjects underwent presurgical orthopedic treatment until the age of approximately 4 months at which time the primary surgery was performed. Main Outcome Measure: The nasal shape following nasal molding should be more symmetrical than if molding had not been done. Results: The mean asymmetry index for the nasoalveolar molding group was 0.74, and the control group was 1.21. This difference was statistically significant (p < .05). Conclusions: Presurgical nasoalveolar molding significantly increases the symmetry of the nose. The increase in symmetry is maintained long term into early childhood. The limitations of this study include (1) asymmetry alone is not an adequate shape result in most situations, (2) the children evaluated in this study were not fully grown, and (3) the control group was not age matched.

Practical electron tomography

1995 ◽  
Vol 53 ◽  
pp. 742-743
Author(s):  
C.L. Woodcock
Keyword(s):  
Electron Tomography ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3D Shape ◽  
Computational Resources ◽  
Shape Of Particles

Despite the potential of the technique, electron tomography has yet to be widely used by biologists. This is in part related to the rather daunting list of equipment and expertise that are required. Thanks to continuing advances in theory and instrumentation, tomography is now more feasible for the non-specialist. One barrier that has essentially disappeared is the expense of computational resources. In view of this progress, it is time to give more attention to practical issues that need to be considered when embarking on a tomographic project. The following recommendations and comments are derived from experience gained during two long-term collaborative projects.Tomographic reconstruction results in a three dimensional description of an individual EM specimen, most commonly a section, and is therefore applicable to problems in which ultrastructural details within the thickness of the specimen are obscured in single micrographs. Information that can be recovered using tomography includes the 3D shape of particles, and the arrangement and dispostion of overlapping fibrous and membranous structures.

convergent-beam diffraction from surfaces

1987 ◽  
Vol 45 ◽  
pp. 30-33
Author(s):  
J. A. Eades ◽  
A. E. Smith ◽  
D. F. Lynch
Keyword(s):  
Reciprocal Lattice ◽  
Three Dimensional ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Plane Figure ◽  
Transmission Electron ◽  
Convergent Beam ◽  
Beam Patterns ◽  
Beam Diffraction

It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

Custom Presurgical Planning for Midfacial Reconstruction

2020 ◽  
Vol 36 (06) ◽  
pp. 696-702
Author(s):  
Nolan B. Seim ◽  
Enver Ozer ◽  
Sasha Valentin ◽  
Amit Agrawal ◽  
Mead VanPutten ◽  
...  
Keyword(s):  
Multidisciplinary Approach ◽  
Functional Performance ◽  
Three Dimensional ◽  
Free Tissue Transfer ◽  
Long Term Effects ◽  
Presurgical Planning ◽  
Dental Rehabilitation ◽  
Midface Reconstruction ◽  
Reconstructive Algorithm

AbstractResection and reconstruction of midface involve complex ablative and reconstructive tools in head and oncology and maxillofacial prosthodontics. This region is extraordinarily important for long-term aesthetic and functional performance. From a reconstructive standpoint, this region has always been known to present challenges to a reconstructive surgeon due to the complex three-dimensional anatomy, the variable defects created, combination of the medical and dental functionalities, and the distance from reliable donor vessels for free tissue transfer. Another challenge one faces is the unique features of each individual resection defect as well as individual patient factors making each preoperative planning session and reconstruction unique. Understanding the long-term effects on speech, swallowing, and vision, one should routinely utilize a multidisciplinary approach to resection and reconstruction, including head and neck reconstructive surgeons, prosthodontists, speech language pathologists, oculoplastic surgeons, dentists, and/or craniofacial teams as indicated and with each practice pattern. With this in mind, we present our planning and reconstructive algorithm in midface reconstruction, including a dedicated focus on dental rehabilitation via custom presurgical planning.

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

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