scholarly journals Modelling of butylated hydroxytoluene (BHT) transport in water in PE-HD pipe including chemical reaction of BHT oxidation

2018 ◽  
Vol 44 ◽  
pp. 00118
Author(s):  
Anna Musz-Pomorska ◽  
Beata Kowalska ◽  
Marcin K. Widomski
Keyword(s):  
Input Data ◽  
Calculated Data ◽  
Butylated Hydroxytoluene ◽  
Pipe Material ◽  
Laboratory Measurements ◽  
Different Types ◽  
Laminar And Turbulent Flow ◽  
Modelling Studies ◽  
Acceptable Agreement ◽  
Pipe Materials

This paper presents laboratory and modelling studies of antioxidant butylated hydroxytoluene leaching from a water supply PE-HD pipe for laminar and turbulent flow. The reaction of BHT oxidation to BHT-OH was included in our calculations. Required input data, initial and boundary conditions were based on laboratory measurements performed for a new PE-HD pipe. Laboratory measurements covered tests of BHT content and homogeneity in pipe material as well as measurements of BHT concentration in water flowing inside the pipe loop with different velocities. The BHT content of the PE-HD pipe and its concentration in water were determined by GC-MS method. Modelling calculations of BHT concentration in water for two different types of flow were performed using the commercial CDF software Fluent (Ansys Inc.). Non-homogeneous BHT distribution in pipe material and leaching of the antioxidant to the water were observed during laboratory tests. Numerical prediction of BHT concentration in water showed acceptable agreement between measured and calculated data. Nonetheless, the universality of the developed model is limited by the great diversity of available plastic pipe materials with various contents and technological amendments.

scholarly journals Optimal Artificial Neural Network Type Selection Method for Usage in Smart House Systems

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 47
Author(s):  
Vasyl Teslyuk ◽  
Artem Kazarian ◽  
Natalia Kryvinska ◽  
Ivan Tsmots
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Artificial Neural Network ◽  
Artificial Neural Networks ◽  
Input Data ◽  
Optimization Criterion ◽  
Fuzzy Input ◽  
Different Types ◽  
Smart House ◽  
Artificial Neural

In the process of the “smart” house systems work, there is a need to process fuzzy input data. The models based on the artificial neural networks are used to process fuzzy input data from the sensors. However, each artificial neural network has a certain advantage and, with a different accuracy, allows one to process different types of data and generate control signals. To solve this problem, a method of choosing the optimal type of artificial neural network has been proposed. It is based on solving an optimization problem, where the optimization criterion is an error of a certain type of artificial neural network determined to control the corresponding subsystem of a “smart” house. In the process of learning different types of artificial neural networks, the same historical input data are used. The research presents the dependencies between the types of neural networks, the number of inner layers of the artificial neural network, the number of neurons on each inner layer, the error of the settings parameters calculation of the relative expected results.

Experimental study and modeling of uranium (VI) transport through ferrous olivine rock columns

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
M. Rovira ◽  
F.Z. El Aamrani ◽  
L. Duro ◽  
Ignasi Casas ◽  
Joan de Pablo ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Reactive Transport ◽  
Calculated Data ◽  
Buffering Capacity ◽  
Retardation Factor ◽  
Reactive Transport Modeling ◽  
Redox Active ◽  
Different Types ◽  
Free Media ◽  
Waste Repositories

The Lovasjärvi intrusion (SE-Finland) contents a high percentage of ferrous olivine (> 65%). This material has been suggested as a redox-active backfill-additive in deep nuclear waste repositories, due to the large Fe(II) proportion in its mineral composition. In order to understand the processes involved in the redox buffering capacity of this material the transport of uranium (VI) through olivine columns was studied. The results showed considerable retardation factor for the U(VI), particularly in carbonate-free media. The experimental data were simulated by means of reactive transport modeling. The best agreement between the experimental and calculated data was obtained considering that the interaction of U(VI) with the olivine surface occurred at two different types of sorption sites. One type accounts for the sorption capacity of the olivine mineral, and a second type accounts for the sorption on amorphous Fe(OH)

Slow Crack Growth Resistance of Parent and Joint Materials From PE4710 Piping for Safety-Related Nuclear Power Plant Piping

2011 ◽  
Author(s):  
S. Kalyanam ◽  
D.-J. Shim ◽  
P. Krishnaswamy ◽  
Y. Hioe
Keyword(s):  
Crack Growth ◽  
Nuclear Power ◽  
Power Plants ◽  
Slow Crack Growth ◽  
Nuclear Industry ◽  
Pipe Material ◽  
Service Water ◽  
Hdpe Pipe ◽  
Pipe Materials ◽  
Hdpe Pipes

HDPE pipes are considered by the nuclear industry as a potential replacement option to currently employed metallic piping for service-water applications. The pipes operate under high temperatures and pressures. Hence HDPE pipes are being evaluated from perspective of design, operation, and service life requirements before routine installation in nuclear power plants. Various articles of the ASME Code Case N-755 consider the different aspects related to material performance, design, fabrication, and examination of HDPE materials. Amongst them, the material resistance (part of Article 2000) to the slow crack growth (SCG) from flaws/cracks present in HDPE pipe materials is an important concern. Experimental investigations have revealed that there is a marked difference (almost three orders less) in the time to failure when the notch/flaw is in the butt-fusion joint, as opposed to when the notch/flaw is located in the parent HDPE material. As part of ongoing studies, the material resistance to SCG was investigated earlier for unimodal materials. The current study investigated the SCG in parent and butt-fusion joint materials of bimodal HDPE (PE4710) pipe materials acquired from two different manufacturers. The various stages of the specimen deformation and failure during the creep test are characterized. Detailed photographs of the specimen side-surface were used to monitor the specimen damage accumulation and SCG. The SCG was tested using a large specimen (large creep frame) as well as using a smaller size specimen (PENT frame) and the results were compared. Further, the effect of polymer orientation or microstructure in the bimodal HDPE pipe on the SCG was studied using specimens with axial and circumferential notch orientations in the parent pipe material.

Uncertainty in Operational Analysis of Two-Lane Highways

2002 ◽  
Vol 1802 (1) ◽  
pp. 105-114 ◽  
Author(s):  
R. Tapio Luttinen
Keyword(s):  
Input Data ◽  
Travel Speed ◽  
Level Of Service ◽  
Model Parameters ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Operational Analysis ◽  
Percent Time ◽  
Different Types ◽  
Percent Time Spent Following

The Highway Capacity Manual (HCM) 2000 provides methods to estimate performance measures and the level of service for different types of traffic facilities. Because neither the input data nor the model parameters are totally accurate, there is an element of uncertainty in the results. An analytical method was used to estimate the uncertainty in the service measures of two-lane highways. The input data and the model parameters were considered as random variables. The propagation of error through the arithmetic operations in the HCM 2000 methodology was estimated. Finally, the uncertainty in the average travel speed and percent time spent following was analyzed, and four approaches were considered to deal with uncertainty in the level of service.

scholarly journals Successes and Difficulties in Calculating Atomic Oscillator Strengths and Transition Rates

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 77 ◽  
Author(s):  
Alan Hibbert
Keyword(s):  
Interstellar Medium ◽  
Ab Initio ◽  
Atomic Structure ◽  
Plasma Diagnostics ◽  
Calculated Data ◽  
Stellar Atmospheres ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Transition Rates ◽  
Laboratory Measurements

There is an on-going need for accurate oscillator strengths to be used in astrophysical applications, particularly in plasma diagnostics and in the modelling of stellar atmospheres and the interstellar medium. There are several databases in regular use which contain some of the required data, although often insufficiently complete, and sometimes not sufficiently accurate. In addition, several atomic structure packages are available through the literature, or from their individual authors, which would allow further calculations to be undertaken. Laboratory measurements provide an important check on the accuracy of calculated data, and the combined efforts of theorists and experimentalists have succeeded in providing data of an accuracy sufficient for some astrophysical applications. However, the insufficiency or inadequacy of atomic data is a continuing problem. We discuss in the context of appropriate examples some of the principal steps which researchers have taken to calculate accurate oscillator strengths, including both ab initio results and also various extrapolation processes which attempt to improve such results. We also present some examples of the main causes of difficulty in such calculations, particularly for complex (many-electron) ions, and indicate ways in which the difficulties might be overcome.

scholarly journals Calibrating Partial Factors – Methodology, Input Data and Case Study of Steel Structures

2019 ◽  
Author(s):  
Vitali Nadolski ◽  
Árpád Rózsás ◽  
Miroslav Sýkora
Keyword(s):  
Input Data ◽  
Structural Reliability ◽  
Construction Materials ◽  
Steel Structures ◽  
Structural Performance ◽  
Limit States ◽  
Different Types ◽  
Load Effects ◽  
Previous Design

Partial factors are commonly based on expert judgements and on calibration to previous design formats. This inevitably results in unbalanced structural reliability for different types of construction materials, loads and limit states. Probabilistic calibration makes it possible to account for plentiful requirements on structural performance, environmental conditions, production and execution quality etc. In the light of ongoing revisions of Eurocodes and the development of National Annexes, the study overviews the methodology of probabilistic calibration, provides input data for models of basic variables and illustrates the application by a case study. It appears that the partial factors recommended in the current standards provide for a lower reliability level than that indicated in EN 1990. Different values should be considered for the partial factors for imposed, wind and snow loads, appreciating the distinct nature of uncertainties in their load effects.

Computer Aided Design of Classic External Geneva Mechanism

2014 ◽  
Vol 1036 ◽  
pp. 662-667
Author(s):  
Iulian Stǎnǎşel ◽  
Florin Blaga ◽  
Traian Buidoş
Keyword(s):  
Computer Program ◽  
Computer Aided Design ◽  
Input Data ◽  
3D Model ◽  
Calculated Data ◽  
Computer Aided ◽  
Precise Movement ◽  
Measurement Devices ◽  
Aided Design ◽  
Intermittent Motion

Geneva mechanism is used as a mechanism for transforming rotary motion into intermittent motion and is able to achieve a precise movement and its lock, which makes it usable in many areas, particularly in timer devices, measurement devices, feed mechanisms, positioning mechanisms, pick-up and transport machinery, textile machinery etc. The studied literature showed that, although it has long been known, this mechanism is still interesting for contemporary researchers. The present paper proposes a method of synthesis and a computer-aided kinematic and dynamic analysis for this mechanism. Based on input data, it was developed a computer program that computes the dimensions of components of Geneva mechanism and determines velocity acceleration and displacement of Geneva wheel. The dimensional calculated data were also used to obtain 3D model of the mechanism.

Design of Hybrid Hydrostatic/Hydrodynamic Journal Bearings for Optimum Self-Compensation Under Misaligning External Loads

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
L. F. Martinez Esparza ◽  
J. G. Cervantes de Gortari ◽  
E. J. Chicurel Uziel
Keyword(s):  
Calculated Data ◽  
Journal Bearings ◽  
Radial Clearance ◽  
Lubrication Equation ◽  
Exact Function ◽  
Laminar And Turbulent Flow ◽  
Bearing Design ◽  
Integral Differential Equations ◽  
The Mathematical Model ◽  
External Loads

A method to design hybrid hydrostatic/hydrodynamic journal bearings, with the criterion of optimized self-compensation under misaligning loads, is presented. An analysis considering laminar and turbulent flow of a Newtonian incompressible lubricant between the bearing and a misaligned shaft, with restricted lubricant supply to each recess, is discussed. The mathematical model considers the modified steady-state Reynolds lubrication equation, an exact function for the local bearing radial clearance with a misaligned shaft, the continuity integral–differential equations at the recess limits, and boundary conditions at the cavitation zone and outer limits. The finite-difference method was used, and a modular computer program was developed. The procedure follows a univariate search to determine the optimum size and position of recesses and therefore obtain the design with the maximum reactive moment under misaligning loads. A validation of the model was obtained comparing the results with experimental and calculated data from the literature. Results for a 4 + 4 LBP hybrid bearing design are presented.

scholarly journals Effects of pipe materials on biofouling under controlled hydrodynamic conditions

2015 ◽  
Vol 6 (1) ◽  
pp. 167-174 ◽  
Author(s):  
S. Gamri ◽  
A. Soric ◽  
S. Tomas ◽  
B. Molle ◽  
N. Roche
Keyword(s):  
Growth Control ◽  
Surface Characteristics ◽  
Primary Role ◽  
Pipe Material ◽  
Hydrodynamic Conditions ◽  
Biofilm Growth ◽  
Pipe Surface ◽  
Biofilm Detachment ◽  
Pvc Pipe ◽  
Pipe Materials

Experiments were carried out to investigate pipe material impacts on biofouling, at high effluent concentration levels and under controlled hydrodynamic conditions. Two velocities (0.4 and 0.8 m s−1) were used to monitor biofilm growth on polyethylene (PE) and polyvinylchloride (PVC) pipe walls, respectively. These conditions were established based on wastewater irrigation practices. A decrease in biomass is observed after 49 days of experiments for both velocities and may be related to biofilm detachment. Biofilm growth is greater at 0.8 m s−1. For both velocities, PVC is less sensitive to biofilm growth than PE. Pipe straightness plays a primary role in biofilm growth control. This effect is more significant than pipe surface characteristics (roughness, hydrophobic/hydrophilic properties).

Mathematical Modelling of Sayano-Shushenskaya Dam Displacement Process after 2009 Accident

2018 ◽  
Vol 39 ◽  
pp. 47-59
Author(s):  
V.S. Khoroshilov
Keyword(s):  
Mathematical Models ◽  
Input Data ◽  
Prognostic Models ◽  
Recurrent Equation ◽  
Conditional Moment ◽  
Transport Delay ◽  
Dynamic Type ◽  
Different Types ◽  
Autoregression Model ◽  
Quantitative Definition

The research presented in the article is of cutting-edge importance because it proves the necessity to develop prognostic mathematical models with the view to studying the behavior of high-head dams for identifying the regularities of their deformations development process and thus providing quantitative definition for the set criteria values of the diagnostic indices to ensure safe operation of such structures. The paper focuses on the peculiarities of building prognostic mathematical models of the dynamic type on the basis of recurrent equations of the 1stand 2ndorders of different types depending on the order of the mathematical model, number of the principal acting factors and discreteness of the input data, with decorrelation of the input actions and sequence of transport delay introduction. It is shown that the properties of the recurrent equation solution in the form of two first conditional moment generating functions of the displacement process of the observed points in the structure delineate a prognostic model which allows predicting the displacements of the observed points. The paper describes the sequence of estimation stages during the creation of prognostic mathematical models in respect to the character of the predictive problem for various time periods of the structure operation. Different combinations of input actions and discreteness of input data, as well as their decorrelation, have been used. We also applied transport delay in order to correctly consider the inertial delay of the dam under different loads. To account for the residual part of the inertial delay, which is affected by random and unaccounted for factors, we used the autoregression model of the process development regularity. To determine the order of the autoregression model, we calculated asymptotically unbiased ratings of the correlation function for the residual error as a difference between the actual and predicted displacements. Methodological specifics of constructing prognostic models have been established in the context of the factors above. Prognostic mathematical models of different types have been developed for the selected period of the dam operation and the results of prediction have been discussed.

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