Assessment of offshore sand and gravel bodies for dredging

1998 ◽  
Vol 13 (1) ◽  
pp. 15-31 ◽  
Author(s):  
Ian Selby ◽  
Klaas Ooms
Keyword(s):  
Three Dimensional ◽  
Site Investigation ◽  
Three Dimensional Model ◽  
Reliable Assessment ◽  
Alternative Approach ◽  
Compositional Variability ◽  
Sand And Gravel ◽  
Sand Bodies ◽  
Selection Of

AbstractReliable assessment of offshore sand and gravel resources permits efficient dredging, the maintenance of cargo quality control and the effective mitigation of environmental impacts. Site investigation should be based on the interpretation and correlation of high resolution seismic profiling and CPT/sampling data. A preliminary interpretation of the seismic data reveals the geological setting of the sand bodies and leads to the selection of appropriate sampling methods and the recognition of key sampling positions. Geologically complex sand bodies demand phased data acquisition to delineate geometry, physical properties and compositional variability. The alternative approach, of grid-based sampling using a predetermined sampling density, is costly at best and probably misleading. A three-dimensional model is created from the integration of acquired data and a resource volume calculated. Dredging constraints and overflow losses are applied to the model resulting in the determination of a reserve volume and critical dredging parameters. It is advisable to carry out a wide-ranging testing programme on the recovered samples to ensure compliance with relevant standards or requirements. The potential penalties for superficial site investigation include delay, unpredictable cargo quality and unforeseen environmental problems.

scholarly journals A Comparison of Different Counting Methods for a Holographic Particle Counter: Designs, Validations and Results

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 3006
Author(s):  
Georg Brunnhofer ◽  
Isabella Hinterleitner ◽  
Alexander Bergmann ◽  
Martin Kraft
Keyword(s):  
Three Dimensional ◽  
Nano Particles ◽  
The Novel ◽  
Computational Speed ◽  
Hologram Plane ◽  
Detection And Counting ◽  
Sampling Volume ◽  
Fringe Patterns ◽  
Selection Of

Digital Inline Holography (DIH) is used in many fields of Three-Dimensional (3D) imaging to locate micro or nano-particles in a volume and determine their size, shape or trajectories. A variety of different wavefront reconstruction approaches have been developed for 3D profiling and tracking to study particles’ morphology or visualize flow fields. The novel application of Holographic Particle Counters (HPCs) requires observing particle densities in a given sampling volume which does not strictly necessitate the reconstruction of particles. Such typically spherical objects yield circular intereference patterns—also referred to as fringe patterns—at the hologram plane which can be detected by simpler Two-Dimensional (2D) image processing means. The determination of particle number concentrations (number of particles/unit volume [#/cm 3 ]) may therefore be based on the counting of fringe patterns at the hologram plane. In this work, we explain the nature of fringe patterns and extract the most relevant features provided at the hologram plane. The features aid the identification and selection of suitable pattern recognition techniques and its parameterization. We then present three different techniques which are customized for the detection and counting of fringe patterns and compare them in terms of detection performance and computational speed.

Conjugate Flow and Heat Transfer Investigation of a Turbo Charger: Part I — Numerical Results

2003 ◽  
Author(s):  
Dieter Bohn ◽  
Tom Heuer ◽  
Karsten Kusterer
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Inlet Temperature ◽  
Three Dimensional Model ◽  
Flow And Heat Transfer ◽  
Turbine Inlet ◽  
Turbo Charger ◽  
Conjugate Calculation

In this paper a three-dimensional conjugate calculation has been performed for a passenger car turbo charger. The scope of this work is to investigate the heat fluxes in the radial compressor which can be strongly influenced by the hot turbine. As a result of this, the compressor efficiency may deteriorate. Consequently, the heat fluxes have to be taken into account for the determination of the efficiency. To overcome this problem a complex three-dimensional model has been developed. It contains the compressor, the oil cooled center housing, and the turbine. 12 operating points have been numerically simulated composed of three different turbine inlet temperatures and four different mass flows. The boundary conditions for the flow and for the outer casing were derived from experimental test data (part II of the paper). Resulting from these conjugate calculations various one-dimensional calculation specifications have been developed. They describe the heat transfer phenomena inside the compressor with the help of a Nusselt number which is a function of an artificial Reynolds number and the turbine inlet temperature.

Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds

2011 ◽  
Vol 32 (3) ◽  
pp. 215-227 ◽  
Author(s):  
Paweł Jóźwik ◽  
Michał Karcz ◽  
Janusz Badur
Keyword(s):  
Numerical Modelling ◽  
Knudsen Diffusion ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Three Dimensional Model ◽  
Toxic Compounds ◽  
Slip Boundary ◽  
Standard Models ◽  
Thermocatalytic Decomposition

Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds In this paper a three-dimensional model for determination of a microreactor's length is presented and discussed. The reaction of thermocatalytic decomposition has been implemented on the base of experimental data. Simplified Reynolds-Maxwell formula for the slip velocity boundary condition has been analysed and validated. The influence of the Knudsen diffusion on the microreactor's performance has also been verified. It was revealed that with a given operating conditions and a given geometry of the microreactor, there is no need for application of slip boundary conditions and the Knudsen diffusion in further analysis. It has also been shown that the microreactor's length could be practically estimated using standard models.

scholarly journals Generation of Novel-Substrate-Accepting Biphenyl Dioxygenases through Segmental Random Mutagenesis and Identification of Residues Involved in Enzyme Specificity

2006 ◽  
Vol 72 (3) ◽  
pp. 2191-2199 ◽  
Author(s):  
Marco Zielinski ◽  
Silke Kahl ◽  
Christine Standfuß-Gabisch ◽  
Beatriz Cámara ◽  
Michael Seeger ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Random Mutagenesis ◽  
Major Influence ◽  
Enzyme Specificity ◽  
Three Dimensional Model ◽  
Wild Type Enzyme ◽  
High Frequencies ◽  
Burkholderia Xenovorans ◽  
Function Relationship

ABSTRACT Aryl-hydroxylating dioxygenases are of interest for the degradation of persistant aromatic pollutants, such as polychlorobiphenyls (PCBs), or as catalysts for the functionalization of aromatic scaffolds. In order to achieve dioxygenation of technical mixtures of PCBs, enzymes with broadened or altered substrate ranges are essential. To alter the substrate specificity of the biphenyl dioxygenase (BphA) of Burkholderia xenovorans LB400, we applied a directed evolution approach that used structure-function relationship data to target random mutageneses to specific segments of the enzyme. The limitation of random amino acid (AA) substitutions to regions that are critical for substrate binding and the exclusion of AA exchanges from positions that are essential for catalytic activity yielded enzyme variants of interest at comparatively high frequencies. After only a single mutagenic cycle, 10 beneficial variants were detected in a library of fewer than 1,000 active enzymes. Compared to the parental BphA, they showed between 5- and 200-fold increased turnover of chlorinated biphenyls, with substituent patterns that rendered them largely recalcitrant to attack by BphA-LB400. Determination of their sequences identified AAs that prevent the acceptance of specific PCBs by the wild-type enzyme, such as Pro334 and Phe384. The results suggest prime targets for subsequent cycles of BphA modification. Correlations with a three-dimensional model of the enzyme indicated that most of the exchanges with major influence on substrate turnover do not involve pocket-lining residues and had not been predictable through structural modeling.

scholarly journals First person – Roberta Azzarelli

Biology Open ◽  
2021 ◽  
Vol 10 (2) ◽  
Keyword(s):  
Developmental Biology ◽  
Stem Cell ◽  
Three Dimensional ◽  
Early Career ◽  
First Person ◽  
Tumor Stem Cells ◽  
Three Dimensional Model ◽  
University Of Cambridge ◽  
Research Associate ◽  
Selection Of

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Roberta Azzarelli is first author on ‘Three-dimensional model of glioblastoma by co-culturing tumor stem cells with human brain organoids’, published in BiO. Roberta conducted the research described in this article while a Rita Levi Montalcini fellow in Roberta Azzarelli's lab at Unit of Cell and Developmental Biology, Department of Biology, University of Pisa, Italy. She is now a research associate in the lab of Anna Philpott at the Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, UK, investigating how stem cell and developmental biology can help tackle cancer.

scholarly journals КОМП’ЮТЕРНА ТЕХНОЛОГІЯ АНАЛІЗУ ТА ДИЗАЙНУ ПРЕДМЕТНОГО СЕРЕДОВИЩА З ПОЗИЦІЇ ВІЗУАЛЬНОГО СПРИЙНЯТТЯ

2020 ◽  
pp. 39-48
Author(s):  
Т. В. Булгакова ◽  
О. В. Полякова ◽  
С. С. Кисіль ◽  
О. Є. Шмельова
Keyword(s):  
Visual Perception ◽  
Quantitative Determination ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Human Being ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Three Dimensional Objects ◽  
Computer Technologies

The purpose of the investigation is the development of computer technology of analysis and design of built environment from the point of its visual perception in the space of its three-dimensional model without using the perspective projections. The methodology were used to achieve the purpose: analysis of the scientific publications on the topic of object environment composition; applied geometry methods, method of division of the geometrical object into simplexes (triangulation), methods of advanced algebra and analytical geometry; computer modeling for construction of the model of visual perception of the environment. Methods of analysis of the three-dimensional model on the basis of modeling of visual perception by means of computer technologies directly in the area of the model without using perspective projections are developed. It is offered to analyze the visual perception of any objects and their relations by means of using the solid angles with the vertices placed in the point of view and the surfaces that surround the visible contours of three-dimensional objects. This approach gives the opportunity to analyze the objects simultaneously regardless their position according to the observer; apart of that, the objects, which are accepted similarly in the reality, will have the same geometrical features during the modeling of visual perception and beside that, the refusal of using of the perspective projections will make possible to avoid the distortion of the images. The algorithm of determination of the solid angles to three-dimensional objects, which is the basis of computer methods of compositional analysis of the object environment from the position of visual perception without the use of perspective projections, is developed. The geometrical model of visual perception by a human being from the certain point of perception is built. It makes possible to define correctly visual features of the object environment and gives the opportunity to analyze the whole surrounding of the observer in the area of 360 degrees. Scientific novelty of the investigation means that the methods of analysis of the three-dimensional model on the basis of modeling of visual perception by means of computer technologies directly in the area of the model without using perspective projections are developed for the first time. The concept of the geometrical model of visual perception by a human being from the certain point of perception is developed. The further development of the methodology of quantitative determination of characteristics of object environment by means of computer technologies is defined. Practical significance shows that the results of the scientific investigation can be used for analysis and judgments of the aesthetic peculiarities of the object environment by means of computer technologies with quantitative determination of characteristics of object environment from the point of its visual perception. Such approach gives the opportunity to develop and create the further certain recommendations and instructions for correction of the existing environment and for the development of the new one.

Synthesis of Three-Dimensional Models from Drawings Based on Spectral Graph Theory

2015 ◽  
Vol 756 ◽  
pp. 598-603 ◽  
Author(s):  
Aleksey Zakharov ◽  
Arkady Zhiznyakov
Keyword(s):  
Graph Theory ◽  
Three Dimensional ◽  
Spectral Graph Theory ◽  
Boundary Representation ◽  
Three Dimensional Model ◽  
Three Dimensional Objects ◽  
Spectral Graph ◽  
Dimensional Models ◽  
Three Dimensional Models

Task of automatic reconstruction of three-dimensional objects by drawing views presented. The algorithm based on a boundary representation of three-dimensional models. The algorithm consists of the following steps: automatic separation of the drawing per the views, determination of three-dimensional coordinates of vertices, definition and marking of wire model primitives, reconstruction of model faces and model elements. The fundamental concept of the algorithm is to find the structural elements of three-dimensional model with usage of pre-specified patterns. The templates are described by means of matrices. Matching algorithm uses spectral graph theory. Reconstruction results are presented.

scholarly journals Automatic determination of an anatomical coordinate system for a three-dimensional model of the human patella

2013 ◽  
Vol 46 (12) ◽  
pp. 2093-2096 ◽  
Author(s):  
Michael J. Rainbow ◽  
Daniel L. Miranda ◽  
Roy T.H. Cheung ◽  
Joel B. Schwartz ◽  
Joseph J. Crisco ◽  
...  
Keyword(s):  
Coordinate System ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Automatic Determination ◽  
Three Dimensional Model

Conjugate Flow and Heat Transfer Investigation of a Turbo Charger

2005 ◽  
Vol 127 (3) ◽  
pp. 663-669 ◽  
Author(s):  
Dieter Bohn ◽  
Tom Heuer ◽  
Karsten Kusterer
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Inlet Temperature ◽  
Three Dimensional Model ◽  
Flow And Heat Transfer ◽  
Turbine Inlet ◽  
Turbo Charger ◽  
Conjugate Calculation

In this paper a three-dimensional conjugate calculation has been performed for a passenger car turbo charger. The scope of this work is to investigate the heat fluxes in the radial compressor, which can be strongly influenced by the hot turbine. As a result of this, the compressor efficiency may deteriorate. Consequently, the heat fluxes have to be taken into account for the determination of the efficiency. To overcome this problem a complex three-dimensional model has been developed. It contains the compressor, the oil cooled center housing, and the turbine. Twelve operating points have been numerically simulated composed of three different turbine inlet temperatures and four different mass flows. The boundary conditions for the flow and for the outer casing were derived from experimental test data (Bohn et al.). Resulting from these conjugate calculations various one-dimensional calculation specifications have been developed. They describe the heat transfer phenomena inside the compressor with the help of a Nusselt number, which is a function of an artificial Reynolds number and the turbine inlet temperature.

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