scholarly journals Scientific Rationale for the Movable Pipeline Technology for Transporting CNG by Sea

2020 ◽  
Vol 28 (3) ◽  
pp. 168-177
Author(s):  
Oleh Mandryk ◽  
Volodymyr Artym ◽  
Mariana Shtohry ◽  
Valerii Zaytsev
Keyword(s):  
Mathematical Model ◽  
Natural Gas ◽  
Frame Structure ◽  
Steel Tubes ◽  
Module Design ◽  
Layer Composite ◽  
Economic Parameters ◽  
The Mathematical Model ◽  
Standard Steel ◽  
Made In

AbstractA new efficient CNG module design for the transportation of natural gas by sea is proposed and substantiated. A mathematical model for determining the technical and economic parameters of a movable pipeline module, which is designed for transporting natural gas in a compressed state and consists of a frame structure, the dimensions of which correspond to the 40-foot marine container size and a pipe coil is described. To facilitate construction, it is proposed that a large portion of the coil be made in the form of a two-layer composite construction. The inner layer consists of standard steel tubes or adapters, and the outer layer is fiberglass wound on them. On the basis of the mathematical model an algorithm and a program were compiled, which allowed to determine the technical and economic parameters of the movable pipeline module. The results obtained for the Caspian region are analyzed.

Effect of bias in hematofluorometer measurements of protoporphyrin in screening programs for lead poisoning.

1985 ◽  
Vol 31 (3) ◽  
pp. 386-390 ◽  
Author(s):  
D G Mitchell ◽  
D Doran
Keyword(s):  
Mathematical Model ◽  
Acetic Acid ◽  
Lead Poisoning ◽  
Whole Blood ◽  
Extraction Method ◽  
Blood Lead ◽  
Cutoff Value ◽  
Screening Programs ◽  
The Mathematical Model ◽  
Made In

Abstract Values for erythrocyte protoporphyrin (EP), measured in our laboratory after extraction with ethyl acetate-acetic acid, were compared with hematofluorometer measurements made in 21 other laboratories. We found that: (a) for samples of patients' blood, hematofluorometer results were 11 to 28% lower than the extraction-based values, depending on the concentration of EP and the mathematical model used; (b) hematofluorometers had mean errors of 0 to 3% for federal proficiency-testing samples; (c) there were no performance differences between fresh and shipped blood for the six laboratories that were analyzing both; (d) a hematofluorometer with a 20% low bias at an EP concentration of 500 micrograms per liter of whole blood (by the extraction method) will not detect about a third of the children whose EP concentration exceeds that cutoff value; and (e) at this same cutoff value for EP, the extraction tests detects about 45% of children whose blood lead exceeds 300 micrograms/L, whereas a 20% low-bias hematofluorometer detects only about 37%.

Fatigue Testing and Analysis of a Deep Water Steel Tube Umbilical

2008 ◽  
Author(s):  
Alan Dobson ◽  
Dave Fogg
Keyword(s):  
Mathematical Model ◽  
Fatigue Testing ◽  
Steel Tube ◽  
Steel Tubes ◽  
Stick Slip ◽  
Stress Variation ◽  
Slip Mechanism ◽  
Deep Waters ◽  
Bending Loads ◽  
The Mathematical Model

Rapid analysis of dynamic umbilical structures during the design phase requires a robust mathematical model of the component stresses due to static and alternating loads. The following discusses the validation of a model, through full scale testing, used to assess the stresses and strains present within steel tubes, in umbilical structures typically used in dynamic service in deep waters, such as found in the Gulf of Mexico and offshore West Coast of Africa. The validation focuses upon the complexity of the mathematical model and the influence of tension magnitude the stick-slip mechanism and the stress variation around the circumference of the tubes when under the influence of bending loads.

Modeling Carbon Monoxide Direct Oxidation in Solid Oxide Fuel Cells

2009 ◽  
Vol 6 (2) ◽  
Author(s):  
Luca Andreassi ◽  
Claudia Toro ◽  
Stefano Ubertini
Keyword(s):  
Mathematical Model ◽  
Carbon Monoxide ◽  
Solid Oxide Fuel Cells ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Direct Oxidation ◽  
Fuel Cell Performance ◽  
The Mathematical Model ◽  
Oxidation Of Carbon Monoxide ◽  
Made In

In the present study, the results of the numerical implementation of a mathematical model of a planar anode-supported SOFC are reported. In particular, model results are validated and discussed when the fuel is a mixture of hydrogen and carbon monoxide, focusing on the importance of simulating direct oxidation of carbon monoxide. The mathematical model is solved in a 3D environment and the key issue is the validation comparing with experimental data, which is made in different operating conditions to establish the reliability of the presented model. The results show the importance of simulating direct oxidation of carbon monoxide and its effect on the fuel cell performance.

A Mathematical Model for the Tooth Geometry of Circular-Cut Spiral Bevel Gears

1991 ◽  
Vol 113 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Z. H. Fong ◽  
Chung-Biau Tsay
Keyword(s):  
Mathematical Model ◽  
Cnc Machining ◽  
Tooth Contact Analysis ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Finite Element Stress Analysis ◽  
Tool Setting ◽  
Spiral Bevel ◽  
The Mathematical Model ◽  
Made In

A complete tooth geometry of the circular-cut spiral bevel gears has been mathematically modeled. The mathematical model has been divided into several independent modules, each representing an individual kinematic relation or tool-setting, with examples included. A comparison with the spiraloid model has also been made in this paper. The mathematical model can be applied to simulate and calculate the tooth profiles for the Duplex Method, Helical Duplex Method, Formate Method, and Modified Roll Method for circular-cut spiral bevel gears. It can also be applied to the computer numerical controlled (CNC) machining, computer-aided finite element stress analysis, and tooth contact analysis (TCA) for the spiral bevel gear.

New Method for Static Analysis of Frame Structures Considered Floor Deformation

2014 ◽  
Vol 501-504 ◽  
pp. 518-522
Author(s):  
Hua Zhang ◽  
Li Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Solution ◽  
State Space ◽  
Static Analysis ◽  
Frame Structure ◽  
Frame Structures ◽  
Internal Forces ◽  
State Method ◽  
The Mathematical Model ◽  
Computation Work

The piecewise continuum technique was used for the frame structure and a series-parallel system was taken for the mathematical model for the structure in which the deformation of floor slab had to be considered, and its state space equations were derived. Then the numerical solution of deformations and internal forces were obtained by using of state method. It is shown that the method of this paper has the advantages of less computation work and high precision.

scholarly journals Analysis of the Liquid Natural Gas Energy Storage basing on the mathematical model

2019 ◽  
Vol 159 ◽  
pp. 231-236 ◽  
Author(s):  
Aleksandra Mikołajczak ◽  
Piotr Krawczyk ◽  
Michalina Kurkus-Gruszecka ◽  
Krzysztof Badyda
Keyword(s):  
Mathematical Model ◽  
Energy Storage ◽  
Natural Gas ◽  
Liquid Natural Gas ◽  
The Mathematical Model

Position Control System of a Trunk in an Upward Airflow

2014 ◽  
Vol 657 ◽  
pp. 699-703
Author(s):  
Petru Gabriel Puiu ◽  
Daniel Drilea ◽  
Dragoş Iulian Nedelcu ◽  
Dragoș Andrioaia
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Physical Model ◽  
Position Control ◽  
Flow Simulations ◽  
Paper Work ◽  
Solid Works ◽  
The Mathematical Model ◽  
Position Control System ◽  
Made In

This paper work presents some aspects of modeling the behavior an object in an upward airflow with possible applications in pneumatic elevators. In the premises known from the literature, was formulated the physical model of corp behavior at air flow varying. In the first stage of the work, was completed in Solid Works the physical model and the functioning simulation in Flow Simulations. The imput data was provided in solving the mathematical model in Matcad 13. To achieve the control system was chose an open sources software solution with SCADA interface made in Pro wiew.

The Optimal Form of Shallow Shells of Revolution with a Small Flexible Stiffness

2014 ◽  
Vol 988 ◽  
pp. 367-370
Author(s):  
Leonid U. Stupishin ◽  
Sergey Emelyanov ◽  
Maksim U. Pereverzev ◽  
Maria L. Moshkevich
Keyword(s):  
Mathematical Model ◽  
Maximum Principle ◽  
Optimal Design ◽  
Shells Of Revolution ◽  
Shallow Shells ◽  
Optimal Form ◽  
The Maximum Principle ◽  
The Mathematical Model ◽  
Made In

An important aspect of the theory of optimal design of shells is a question technology of determination of optimal forms of shells with numerical methods, based on the variation definitions. The distribution of effort in sloping shell of revolution optimal form, uniformly loaded with despens intensity is analyzed. The mathematical model of shell optimal form is based on the maximum principle of L.S. Pontryagin. The solution of the objective is numerically made in MathCad. The relations of the distribution of the longitudinal forces and moments along the radius of the shell is shown.

A New Mathematical Model of the Force in Pneumatic Tire-Snow Chain Systems

2006 ◽  
Author(s):  
Juan C. Botero ◽  
Massimiliano Gobbi ◽  
Giampiero Mastinu
Keyword(s):  
Mathematical Model ◽  
Theoretical Model ◽  
Traction Force ◽  
Experimental Tests ◽  
Safety Device ◽  
Transmitted Force ◽  
Basic Concepts ◽  
External Forces ◽  
The Mathematical Model ◽  
Made In

In this paper a new theoretical model to estimate the transmitted force in a snow-chain safety device is presented. Starting with a detailed analysis of the significant external forces acting on the system, the mathematical model is developed using some basic concepts of the contact mechanics theory. A MATLAB® code was developed in order to perform numerical simulations and experimental tests were carried out to validate the model. The results obtained show that for certain conditions of the driving surface and the tire's tread the force transmitted along the chain can be several times the longitudinal traction force applied to the tire itself. The importance of the interaction between the blocks on the tire and the chain segments is discussed. Some conclusions and recommendations are made in order to improve the design process of this kind of devices.

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