Laboratory Study of Hydraulic Conductivity for Coarse Aggregate Bases

1996 ◽  
Vol 1519 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Brian W. Randolph ◽  
Jiangeng Cai ◽  
Andrew G. Heydinger ◽  
Jiwan D. Gupta
Keyword(s):  
Hydraulic Conductivity ◽  
Large Scale ◽  
Base Material ◽  
Testing Procedure ◽  
Test Methods ◽  
Standard Test ◽  
Coarse Grained ◽  
Test Results ◽  
Wide Range ◽  
Pavement Structures

Inadequate drainage of pavement structures has been identified as a primary cause of pavement distress. Hydraulic conductivity is the most important factor controlling drainage capability. Coarse grained materials have high values of hydraulic conductivity. ASTM and AASHTO standard test methods are limited for coarse materials used in pavement bases and subbases because of their high permeability and large particle sizes and the horizontal flow in the field conditions. A large scale horizontal permeameter and a testing procedure were developed and the range of hydraulic conductivities of six base and subbase specifications made up of three material types provided by the Ohio Department of Transportation were evaluated. A horizontal permeameter (305 × 305 × 457 mm) and a testing procedure were developed to reduce errors produced by sidewall leakage, partial saturation, measurement of small head differences, and interpretation of turbulent flow as laminar flow. Fifty-four samples were tested, including various gradations of nonstabilized, portland cement stabilized, and asphalt stabilized bases made of limestone, gravel, or slag materials. The results obtained were analyzed and compared with previous research, empirical relations, and field test results of similar base and subbase materials. The comparisons and analyses indicate that the permeameter and the procedure produce representative results. Test results indicate a wide range of hydraulic conductivities for gradations at each extreme of a specification. Effective porosities were also found to be as low as 6 percent for the fine gradation of a common limestone base material.

scholarly journals Predictive modelling of soils’ hydraulic conductivity using artificial neural network and multiple linear regression

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Charles Gbenga Williams ◽  
Oluwapelumi O. Ojuri
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Hydraulic Conductivity ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Coarse Grained ◽  
Soil Types ◽  
Wide Range ◽  
Artificial Neural ◽  
Input Variables

AbstractAs a result of heterogeneity nature of soils and variation in its hydraulic conductivity over several orders of magnitude for various soil types from fine-grained to coarse-grained soils, predictive methods to estimate hydraulic conductivity of soils from properties considered more easily obtainable have now been given an appropriate consideration. This study evaluates the performance of artificial neural network (ANN) being one of the popular computational intelligence techniques in predicting hydraulic conductivity of wide range of soil types and compared with the traditional multiple linear regression (MLR). ANN and MLR models were developed using six input variables. Results revealed that only three input variables were statistically significant in MLR model development. Performance evaluations of the developed models using determination coefficient and mean square error show that the prediction capability of ANN is far better than MLR. In addition, comparative study with available existing models shows that the developed ANN and MLR in this study performed relatively better.

scholarly journals Experimental Investigation of Wave-Induced Ship Hydroelastic Vibrations by Large-Scale Model Measurement in Coastal Waves

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jialong Jiao ◽  
Huilong Ren ◽  
Shuzheng Sun ◽  
Christiaan Adika Adenya
Keyword(s):  
Large Scale ◽  
Testing Procedure ◽  
Scale Model ◽  
Sea Waves ◽  
Load Pressure ◽  
Large Scale Model ◽  
Wide Range ◽  
Hydroelastic Vibrations ◽  
Wave Induced ◽  
Model Measurement

Ship hydroelastic vibration is an issue involving mutual interactions among inertial, hydrodynamic, and elastic forces. The conventional laboratory tests for wave-induced hydroelastic vibrations of ships are performed in tank conditions. An alternative approach to the conventional laboratory basin measurement, proposed in this paper, is to perform tests by large-scale model measurement in real sea waves. In order to perform this kind of novel experimental measurement, a large-scale free running model and the experiment scheme are proposed and introduced. The proposed testing methodology is quite general and applicable to a wide range of ship hydrodynamic experimental research. The testing procedure is presented by illustrating a 5-hour voyage trial of the large-scale model carried out at Huludao harbor of China in August 2015. Hammer tests were performed to identify the natural frequencies of the ship model at the beginning of the tests. Then a series of tests under different sailing conditions were carried out to investigate the vibrational characteristics of the model. As a postvoyage analysis, load, pressure, acceleration, and motion responses of the model are studied with respect to different time durations based on the measured data.

scholarly journals Classification of protein–protein association rates based on biophysical informatics

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kalyani Dhusia ◽  
Yinghao Wu
Keyword(s):  
Large Scale ◽  
Cross Validation ◽  
Protein Complexes ◽  
Dynamic Properties ◽  
Conformational Dynamics ◽  
Classification Model ◽  
Coarse Grained ◽  
Modeling Framework ◽  
Validation Data ◽  
Wide Range

Abstract Background Proteins form various complexes to carry out their versatile functions in cells. The dynamic properties of protein complex formation are mainly characterized by the association rates which measures how fast these complexes can be formed. It was experimentally observed that the association rates span an extremely wide range with over ten orders of magnitudes. Identification of association rates within this spectrum for specific protein complexes is therefore essential for us to understand their functional roles. Results To tackle this problem, we integrate physics-based coarse-grained simulations into a neural-network-based classification model to estimate the range of association rates for protein complexes in a large-scale benchmark set. The cross-validation results show that, when an optimal threshold was selected, we can reach the best performance with specificity, precision, sensitivity and overall accuracy all higher than 70%. The quality of our cross-validation data has also been testified by further statistical analysis. Additionally, given an independent testing set, we can successfully predict the group of association rates for eight protein complexes out of ten. Finally, the analysis of failed cases suggests the future implementation of conformational dynamics into simulation can further improve model. Conclusions In summary, this study demonstrated that a new modeling framework that combines biophysical simulations with bioinformatics approaches is able to identify protein–protein interactions with low association rates from those with higher association rates. This method thereby can serve as a useful addition to a collection of existing experimental approaches that measure biomolecular recognition.

Progress on Environmentally Compliant Aluminum Ceramic Compressor Coatings

2004 ◽  
Author(s):  
Mark F. Mosser
Keyword(s):  
Ceramic Coatings ◽  
Test Methods ◽  
Standard Test ◽  
Toxic Substances ◽  
Test Results ◽  
Coating Materials ◽  
Environmental Laws ◽  
Environmental Test ◽  
Aluminum Paint ◽  
Steel Substrates

During the last decade there has been an increasing emphasis on compliance to ever stricter environmental laws as well as compliance to regulations that have been designed to protect workers from exposure to toxic or otherwise harmful substances or processes. This world-wide emphasis has forced a continuing review of materials and processes used in the manufacture and protection of compressor materials from corrosion. Turbine compressors have been coated with silicone aluminum paint, diffused nickel cadmium and aluminum pigmented ceramic coatings that contain hexavalent chromium. These three processes utilize various chemicals including toxic substances, carcinogens and volatile organic compounds (VOC). All three of the coating processes need to be either made compliant or eliminated from use. This paper will review efforts that have been made to develop compliant aluminum ceramic compressor coating materials as applied to various steel and stainless steel substrates. In all cases the new materials that have been developed are free of toxic or carcinogenic materials. Test results will be compared to specification requirements for chrome containing compressor coatings in the area of physical properties including surface finish, thickness and adhesion. Additionally, environmental test data will be presented based on standard test methods that compare new compliant coatings with conventional chrome containing materials. Finally, process steps and conditions will be described for these new coatings.

Mechanical Behaviour of a Forged Ferritic Steel Shell Containing Numerous Hydrogen Flakes

2018 ◽  
Author(s):  
C. Jacquemoud ◽  
I. Delvallée-Nunio
Keyword(s):  
Steam Generator ◽  
Large Scale ◽  
Base Material ◽  
Scientific Basis ◽  
Pressure Vessels ◽  
Steel Shell ◽  
Test Results ◽  
Transition Range ◽  
Fem Simulations ◽  
Fatigue Precrack

Following the flaw indications found in summer 2012 in two Belgian Reactors Pressure Vessels (RPV), WENRA recommended [1] the nuclear safety authorities in Europe to verify the material quality and integrity of the RPV in a 2-step approach: 1) a comprehensive review of the manufacturing and inspection records of the forgings of the RPV, 2) an additional UT examination of the base material of the vessels if needed. In this context, and to consolidate scientific basis on this issue, IRSN, the French technical safety organization, conducted, with CEA support, a test program aiming at studying the consequences of hydrogen flakes in large forgings of primary equipment (RPV, steam generator, pressurizer). Framatome provided the material to be investigated, namely two blocks of a steam generator vessel shell in 18MND5 steel: a block without flake — the reference block — and a block including a high density of hydrogen flakes. This shell — so called VB395 — was rejected because of an incident which occurred during the degassing heat treatment. Fracture toughness has been evaluated from 85 tests in the ductile range and the ductile-to-brittle transition range of the material. The test results on usual 0.5T-CT specimens were compared to those on specimens containing a hydrogen flake replacing the fatigue precrack. The latter were interpreted using 3D elastic-plastic X-FEM simulations allowing the modelling of the irregular flake geometry. Furthermore, large scale bending specimens with multiple flakes have been tested at −100°C. These tests were interpreted thanks to 3D X-FEM simulations allowing the analysis of the hydrogen flake interaction in terms of KJ.

scholarly journals Evaluation of JATSdecoder as an automated text extraction tool for statistical results in scientific reports

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ingmar Böschen
Keyword(s):  
R Package ◽  
Psychological Research ◽  
Standard Test ◽  
Test Results ◽  
Data Set ◽  
Detection Rates ◽  
Textual Representations ◽  
Wide Range ◽  
Input Format ◽  
Statistical Results

AbstractThe extraction of statistical results in scientific reports is beneficial for checking studies on plausibility and reliability. The R package JATSdecoder supports the application of text mining approaches to scientific reports. Its function get.stats() extracts all reported statistical results from text and recomputes p values for most standard test results. The output can be reduced to results with checkable or computable p values only. In this article, get.stats()’s ability to extract, recompute and check statistical results is compared to that of statcheck, which is an already established tool. A manually coded data set, containing the number of statistically significant results in 49 articles, serves as an initial indicator for get.stats()’s and statcheck’s differing detection rates for statistical results. Further 13,531 PDF files by 10 mayor psychological journals, 18,744 XML documents by Frontiers of Psychology and 23,730 articles related to psychological research and published by PLoS One are scanned for statistical results with both algorithms. get.stats() almost replicates the manually extracted number of significant results in 49 PDF articles. get.stats() outperforms the statcheck functions in identifying statistical results in every included journal and input format. Furthermore, the raw results extracted by get.stats() increase statcheck’s detection rate. JATSdecoder’s function get.stats() is a highly general and reliable tool to extract statistical results from text. It copes with a wide range of textual representations of statistical standard results and recomputes p values for two- and one-sided tests. It facilitates manual and automated checks on consistency and completeness of the reported results within a manuscript.

An Elastoplastic Model for Coarse Grained Soils Obeying Lade's Dilatancy Rule

2013 ◽  
Vol 850-851 ◽  
pp. 381-386
Author(s):  
Jin Wang ◽  
Jiao Na Li ◽  
Sheng Zhu
Keyword(s):  
Potential Function ◽  
Yield Surface ◽  
Large Scale ◽  
Coarse Grained ◽  
Triaxial Tests ◽  
Surface Model ◽  
Test Results ◽  
Elastoplastic Model ◽  
Plastic Potential ◽  
Plastic Potential Function

This paper discussed the mechanism of dilatancy in coarse grained soils. Large-scale triaxial tests were also conducted to study the dilatancy law of coarse grained soils. Based on the results of the previous studies, it is found that plastic potential function proposed by Lade can fit the test results well. Lades dilatancy rule was then applied to a practical two-yield-surface model. Elastoplastic formula of the two-yield-surface model was also deduced in detail. The new model was verified with several groups of different materials. Results showed that this model could predict the behaviors of coarse grained soils well.

The Comparison of Methods of Testing Enameled Wire to Mechanical Stress

2015 ◽  
Vol 792 ◽  
pp. 33-37
Author(s):  
Andrey Leonov ◽  
Adelya Supueva
Keyword(s):  
Mechanical Strength ◽  
Mechanical Stress ◽  
Test Methods ◽  
Standard Test ◽  
Mechanical Resistance ◽  
Insulation Resistance ◽  
Comparison Of Methods ◽  
Test Results ◽  
Mechanical Loads

This work presents the test results of the enameled winding wires, characterizing an insulation mechanical strength. The standard and original test methods were used. It should be noted that the existing standard test methods do not estimate enamel insulation resistance to the mechanical loads authentically. Note that the estimation of wire mechanical resistance can be done by the determination of the number of defects in the enamel insulation. The results of tests for wires with various types of insulation are presented.

scholarly journals Martini Coarse-Grained Model of Hyaluronic Acid for the Structural Change of Its Gel in the Presence of Monovalent and Divalent Salts

2020 ◽  
Vol 21 (13) ◽  
pp. 4602 ◽  
Author(s):  
Raj Kumar ◽  
Young Kyu Lee ◽  
Yong Seok Jho
Keyword(s):  
Hyaluronic Acid ◽  
Large Scale ◽  
Structural Changes ◽  
Coarse Grained ◽  
Radius Of Gyration ◽  
Main Role ◽  
Structural Formation ◽  
Wide Range ◽  
Distinct Property ◽  
End Distance

Hyaluronic acid (HA) has a wide range of biomedical applications including the formation of hydrogels, microspheres, sponges, and films. The modeling of HA to understand its behavior and interaction with other biomolecules at the atomic level is of considerable interest. The atomistic representation of long HA polymers for the study of the macroscopic structural formation and its interactions with other polyelectrolytes is computationally demanding. To overcome this limitation, we developed a coarse grained (CG) model for HA adapting the Martini scheme. A very good agreement was observed between the CG model and all-atom simulations for both local (bonded interactions) and global properties (end-to-end distance, a radius of gyration, RMSD). Our CG model successfully demonstrated the formation of HA gel and its structural changes at high salt concentrations. We found that the main role of CaCl2 is screening the electrostatic repulsion between chains. HA gel did not collapse even at high CaCl2 concentrations, and the osmotic pressure decreased, which agrees well with the experimental results. This is a distinct property of HA from other proteins or polynucleic acids which ensures the validity of our CG model. Our HA CG model is compatible with other CG biomolecular models developed under the Martini scheme, which allows for large-scale simulations of various HA-based complex systems.

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