scholarly journals Analytical Criterion for the Strength of Bonded-Dispersed Gels During Pipeline Transportation

2021 ◽  
Vol 24 (2) ◽  
pp. 9-15
Author(s):  
Bogdan Sheludchenko ◽  
Iryna Slusarenko ◽  
Oleh Pluzhnikov ◽  
Vladyslav Shubenko ◽  
Victor Biletsky ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Transport Systems ◽  
Design Parameters ◽  
Design Calculation ◽  
Pipeline Transport ◽  
Wide Range ◽  
Pipeline Systems ◽  
The Creation ◽  
Further Development ◽  
Product Pipeline

Modern pipeline systems, both main and industrial, allow transporting a wide range of liquid and gaseous substances, including a variety of solid bulk materials, minerals, building materials and mixtures. However, the development of pipeline transport systems today is hindered by the lack of theoretical developments in the implementation of practical engineering projects for the creation of both main and industrial product pipelines for various purposes. Therefore, the further development of the theory of flows of various substances in pipelines and the creation of universal methods for engineering calculations of design parameters of pipeline systems based on this theory are priority tasks for the further development of product pipeline transport. The studies were carried out in accordance with the condition of stochastic transformation of the coagulation-thixotropic structure of the gel flow into sol. Such a stochastic transformation of the coagulation-thixotropic structure can be observed both when reaching the mode that determines the turbulent motion of a viscous colloidal solution, and somewhat earlier – at the stages of the laminar flow regime of the solution. Based on the formal phenomenological analysis, it has been determined that during the transition of the laminar mode of motion of the Newton fluid flow in a cylindrical tube to the turbulent mode, the transported structured gel flow is guaranteed to collapse into a colloidal sol. Based on the example of a typical design calculation of a technological (production) pipeline for the transportation of motor oils of the SAE-10 and SAE-40 grades, the optimal conditional internal diameters of the product pipeline were determined. The compliance of the design structural parameters of the pipelines with the corresponding physical and mechanical properties of the transported liquids was established. The proposed methods of engineering calculations of design parameters for technical objects of pipeline transport should expand and supplement the regulatory documentation for the preparation of projects for the construction of both main product pipelines and technological “interoperable” production pipelines

Design Optimization of a Novel Tripedal Locomotion Robot Through Simulation and Experiments for a Single Step Dynamic Gait

2007 ◽  
Author(s):  
Jeremy R. Heaston ◽  
Dennis W. Hong
Keyword(s):  
Sagittal Plane ◽  
Single Step ◽  
The Body ◽  
Design Parameters ◽  
Walking Robot ◽  
Wide Range ◽  
Mass Properties ◽  
Future Work ◽  
Dynamic Gait ◽  
Further Development

This paper presents the concept and design of a unique three-legged walking robot, and results from the simulation and experiments of a single step tripedal gait. The STriDER (Self-excited Tripedal Dynamic Experimental Robot) incorporates aspects of passive dynamic walking into a stable tripedal platform and is capable of changing directions. To initiate a step, the legs are oriented to push the center of gravity outside of the stance polygon, and as the body of the robot falls forward, the swing leg naturally swings in between the two stance legs and catches the fall. Once all three legs are in contact with the ground, the robot regains its stability and the posture of the robot is then reset in preparation for the next step. The changing of the direction is done by a unique way of changing the sequence of which of the three legs is the swing leg. To guide the design of the robot, a dynamic model was developed and a simulation of a single step tripedal gait was performed to allow for tuning of several design parameters, including the mass properties and link dimensions. By considering the two stance legs as a single effective link connected to the ground, the robot can be modeled as a planar four-link pendulum in the sagittal plane. Further development of the simulation also allowed for optimization of the design parameters to create an ideal gait for the robot. A self-excited method of actuation, which seeks to drive a stable system toward instability, was used to control the robot. This method of actuation was found to be robust across a wide range of design parameters and relatively insensitive to controller gains. The design of the first prototype and result from the experiments are presented with a discussion of future work.

scholarly journals Creating the knowledge base and data banks to justify the strength reliability of the pipeline transport system for oil and petroleum products

2020 ◽  
Vol 4 (1) ◽  
pp. 28-42
Author(s):  
Nikolay A. Makhutov ◽  
◽  
Dmitry A. Neganov ◽  
Keyword(s):  
Knowledge Base ◽  
Transport System ◽  
Damage Tolerance ◽  
Practical Importance ◽  
Petroleum Products ◽  
Knowledge Bases ◽  
Transport Systems ◽  
Pipeline Transport ◽  
Further Development ◽  
Data Banks

The paper outlines the scientific fundamentals for creating and applying the knowledge bases and the data banks in the design, construction and operation of pipeline transport systems. The analysis of knowledge is carried out, the main directions of knowledge base creation and its fundamentals are considered in terms of the pipeline transport of oil and petroleum products. The knowledge bases include both the existing system of scientifically validated proposals to the structure, classification, criteria, constitutive equations for design-and-experimental assessment of strength, stability, stiffness of the load-bearing elements of pipeline transport facilities, and further development of these proposals in terms of analyzing the operation life, reliability, and damage tolerance of the pipeline transport system, analysis of its protection against crisis and emergency situations. Data banks are considered as the initial information basis for the knowledge implementation at all stages of the pipeline transport system life cycle. It is concluded that the creation of the unified system of knowledge base and data banks is of significant scientific and practical importance for the further development of pipeline transport systems with regard to up-to-date requirements for ensuring and improving their strength, service life, reliability, damage tolerance, and safety of construction and operation.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Conclusion

2018 ◽  
Author(s):  
Rachel Crossland
Keyword(s):  
Literature And Science ◽  
Evaluative Criteria ◽  
Specific Potential ◽  
The Creation ◽  
The Moment ◽  
Further Development

The conclusion returns to some of the ideas raised in the Introduction, specifically Gillian Beer’s suggestion that literature and science ‘share the moment’s discourse’. It argues for the relevance of this model to different periods and disciplines, while also suggesting some specific potential areas for further development in relation to the present study, including generalist periodicals. It also considers some of the evaluative criteria that have previously been suggested for studies in the field of literature and science, and raises some questions as to the direction in which that field of research should now move. The study concludes finally by suggesting that literature and science, as well as a range of other disciplines, some of which are included here, do more than share the moment’s discourse—they share in the creation, development, and modification of that discourse because they share the moment itself.

scholarly journals Importance of $${{d}}_{{{xy}}}$$ orbital and electron correlation in iron-based superconductors revealed by phase diagram for 1111-system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsuyoshi Kawashima ◽  
Shigeki Miyasaka ◽  
Hirokazu Tsuji ◽  
Takahiro Yamamoto ◽  
Masahiro Uekubo ◽  
...  
Keyword(s):  
Electron Correlation ◽  
Weak Coupling ◽  
Structural Parameters ◽  
Structural Flexibility ◽  
Superconducting Transition ◽  
Iron Based Superconductors ◽  
Wide Range ◽  
Band Filling ◽  
Iron Based ◽  
Correlation Strength

AbstractThe structural flexibility at three substitution sites in LaFeAsO enabled investigation of the relation between superconductivity and structural parameters over a wide range of crystal compositions. Substitutions of Nd for La, Sb or P for As, and F or H for O were performed. All these substitutions modify the local structural parameters, while the F/H-substitution also changes band filling. It was found that the superconducting transition temperature $$T_{\text{c}}$$ T c is strongly affected by the pnictogen height $$h_{Pn}$$ h Pn from the Fe-plane that controls the electron correlation strength and the size of the $$d_{xy}$$ d xy hole Fermi surface (FS). With increasing $$h_{Pn}$$ h Pn , weak coupling BCS superconductivity switches to the strong coupling non-BCS one where electron correlations and the $$d_{xy}$$ d xy hole FS may be important.

scholarly journals Performance and problems of the housing sphere in Russia

2018 ◽  
Vol 251 ◽  
pp. 06029
Author(s):  
Ekaterina Dmitrieva
Keyword(s):  
Risk Factors ◽  
Risk Prevention ◽  
Effective Management ◽  
Risk Zones ◽  
The Creation ◽  
Further Development

Systematization of risks in the field of housing-and-communal services and recommendations on the neutralization of problem zones were offered. The objective is the diagnostics of the situation in the sphere of housing-and-communal services and the identification of risk zones. The author concludes that the information on risk factors is necessary for the creation of the system of risk prevention, and assumes further development of the measures for the effective management in this sector.

scholarly journals Multi-stable composite twisting structure for morphing applications

2012 ◽  
Vol 468 (2141) ◽  
pp. 1230-1251 ◽  
Author(s):  
X. Lachenal ◽  
P. M. Weaver ◽  
S. Daynes
Keyword(s):  
Analytical Model ◽  
Material Properties ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Engineering Structures ◽  
The Past ◽  
Wide Range ◽  
Morphing Structure ◽  
Low Mass ◽  
Unstable States

Conventional shape-changing engineering structures use discrete parts articulated around a number of linkages. Each part carries the loads, and the articulations provide the degrees of freedom of the system, leading to heavy and complex mechanisms. Consequently, there has been increased interest in morphing structures over the past decade owing to their potential to combine the conflicting requirements of strength, flexibility and low mass. This article presents a novel type of morphing structure capable of large deformations, simply consisting of two pre-stressed flanges joined to introduce two stable configurations. The bistability is analysed through a simple analytical model, predicting the positions of the stable and unstable states for different design parameters and material properties. Good correlation is found between experimental results, finite-element modelling and predictions from the analytical model for one particular example. A wide range of design parameters and material properties is also analytically investigated, yielding a remarkable structure with zero stiffness along the twisting axis.

scholarly journals Use of simulation model for measurement of MilkRun system performance

2019 ◽  
Vol 9 (1) ◽  
pp. 600-605 ◽  
Author(s):  
Gabriel Fedorko ◽  
Martin Vasil ◽  
Michaela Bartosova
Keyword(s):  
Simulation Model ◽  
Production Systems ◽  
Operational Performance ◽  
Transport Systems ◽  
Indirect Methods ◽  
Operational Characteristics ◽  
Wide Range ◽  
Effective Operation ◽  
And Performance ◽  
Plant Simulation

AbstractIntra-plant transport systems within their operation directly impact on the performance of production systems. For their effective operation, it is, therefore, necessary to realize evaluation of operational performance and effectivity. For the realization of this type of evaluation, in addition to a wide range of sensors that can be difficult for installation and operation, we can also use indirect methods that are equally able to provide reliable operational characteristics. Indirect analytical methods are presented above all by the approach which is based on the use of simulation methods. The method of computer simulation provides a wide range of options for the evaluation of efficiency and performance. The paper describes the use of a simulation model created in the program Tecnomatix Plant Simulation for analyzing the supply of production workplaces within the MilkRun system.

Closed-Form Correlation of Buildings Energy Use With Key Design Parameters Calibrated Using a Genetic Algorithm

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Raed I. Bourisli ◽  
Adnan A. AlAnzi
Keyword(s):  
Genetic Algorithm ◽  
Closed Form ◽  
Energy Use ◽  
Building Design ◽  
Office Buildings ◽  
Design Parameters ◽  
Wide Range ◽  
Variable Function ◽  
Real Coded Genetic Algorithm ◽  
The Difference

This work aims at developing a closed-form correlation between key building design variables and its energy use. The results can be utilized during the initial design stages to assess the different building shapes and designs according to their expected energy use. Prototypical, 20-floor office buildings were used. The relative compactness, footprint area, projection factor, and window-to-wall ratio were changed and the resulting buildings performances were simulated. In total, 729 different office buildings were developed and simulated in order to provide the training cases for optimizing the correlation’s coefficients. Simulations were done using the VisualDOE TM software with a Typical Meteorological Year data file, Kuwait City, Kuwait. A real-coded genetic algorithm (GA) was used to optimize the coefficients of a proposed function that relates the energy use of a building to its four key parameters. The figure of merit was the difference in the ratio of the annual energy use of a building normalized by that of a reference building. The objective was to minimize the difference between the simulated results and the four-variable function trying to predict them. Results show that the real-coded GA was able to come up with a function that estimates the thermal performance of a proposed design with an accuracy of around 96%, based on the number of buildings tested. The goodness of fit, roughly represented by R2, ranged from 0.950 to 0.994. In terms of the effects of the various parameters, the area was found to have the smallest role among the design parameters. It was also found that the accuracy of the function suffers the most when high window-to-wall ratios are combined with low projection factors. In such cases, the energy use develops a potential optimum compactness. The proposed function (and methodology) will be a great tool for designers to inexpensively explore a wide range of alternatives and assess them in terms of their energy use efficiency. It will also be of great use to municipality officials and building codes authors.

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