Modelling of tribological responses of composites using integrated ANN-GA technique

2020 ◽  
pp. 002199832096052
Author(s):  
Santanu Sardar ◽  
Swati Dey ◽  
Debdulal Das
Keyword(s):  
Optimization Technique ◽  
Matrix Composites ◽  
Large Numbers ◽  
Wide Range ◽  
Input Parameters ◽  
Input Variables ◽  
Velocity Input ◽  
Abrasive Size

In the present article, artificial neural networks (ANNs) and genetic algorithm (GA) methodology were integrated to model tribological characteristics of stir-cast Al-Zn-Mg-Cu matrix composites under two-body abrasion considering large numbers of experimentally generated results. Tribo-responses of wear rate (Wrt), coefficient of friction (COF) and roughness of abraded surface (RAS) were evaluated under wide range of intrinsic ( i.e., particle quantity) and extrinsic ( i.e., abrasive size, load, distance and velocity) input parameters. Characteristics of Wrt, COF and RAS are often mutually contradictory in nature and so, multi-objective optimization technique becomes imperative for selection and design of machine components. Accordingly, those were optimized through Pareto solutions. Sensitivity of different factors was analyzed on each of the tribo-performances and validated via experimental evidences. Amongst the input variables, particle quantity and abrasive size dominated significantly over other variables except load which imparted modest influences. The role of various input parameters was explained through determination of different micromechanisms via exhaustive post wear characterizations, microstructural and surface topography attributes. Lowest values of Wrt and COF with a modest value of RAS were identified at 15 ± 2 wt.% particle quantity.

Willows in the environment

1992 ◽  
Vol 98 ◽  
pp. 215-224 ◽  
Author(s):  
Alastair H. C. Sommerville
Keyword(s):  
Plant Communities ◽  
Ecological Role ◽  
Large Numbers ◽  
Wide Range

SynopsisThe ecological role of native willows is described in terms of the diverse structure of the species involved, the wide range of plant communities they form and the large numbers of invertebrates associated with them. The conservation importance of the genusSalixis discussed along with comments on the necessary management to retain willow habitats.

The Role of Multivariant Analysis on the Interpretation of FTIR and Raman Spectra

2020 ◽  
pp. 104-129 ◽  
Author(s):  
Sefa Celik ◽  
Ali Tugrul Albayrak ◽  
Sevim Akyuz ◽  
Aysen E. Ozel
Keyword(s):  
Biological Systems ◽  
Principal Component ◽  
Biological Macromolecules ◽  
Spectroscopic Techniques ◽  
Linear Discriminant ◽  
Wide Range ◽  
Vibrational Bands ◽  
Multivariant Analysis

FTIR and Raman spectroscopy are complementary spectroscopic techniques that play an important role in the analysis of molecular structure and the determination of characteristic vibrational bands. Vibrational spectroscopy has a wide range of applications including mainly in physics and biology. Its applications have gained tremendous speed in the field of biological macromolecules and biological systems, such as tissue, blood, and cells. However, the vibrational spectra obtained from the biological systems contain a large number of data and information that make the interpretation difficult. To facilitate the analysis, multivariant analysis comprising the reduction of the dimension of spectrum data and classification of them by eliminating redundancy data, which are obtained from the spectra and does not have any role, becomes critical. In this chapter, the applications of Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and their combination PCA-LDA, which are widely used among multivariant techniques on biological systems will be disclosed.

Paper 28: The Role of Managerial Practice and Analytical Method in the Reduction of Defect and Failure Losses

1969 ◽  
Vol 184 (2) ◽  
pp. 203-207
Author(s):  
W. T. Truscott
Keyword(s):  
Analytical Method ◽  
Analytical Techniques ◽  
Good Effect ◽  
Technical Competence ◽  
Tolerance Level ◽  
Large Numbers ◽  
Wide Range ◽  
Failure Losses ◽  
Financial Losses

The level of continuing financial losses due to defects and failures is often dependent to a large extent on the tolerance level of management and the degree of technical competence shown in dealing with large numbers of singularly trivial, but collectively significant, faults to good effect. Some practices for the manager and analytical techniques for the engineer which have been successful in reducing such faults on a wide range of industrial product are reviewed.

scholarly journals Optimization of Cutting Conditions in End Milling Process with the Approach of Particle Swarm Optimization

2011 ◽  
pp. 120-124
Author(s):  
Vikas Pare ◽  
Geeta Agnihotri ◽  
C.M. Krishna
Keyword(s):  
Surface Roughness ◽  
Particle Swarm Optimization ◽  
Surface Finish ◽  
Metal Cutting ◽  
End Milling ◽  
Optimization Technique ◽  
Particle Swarm ◽  
Swarm Optimization ◽  
Wide Range ◽  
Input Variables

Milling is one of the progressive enhancements of miniaturized technologies which has wide range of application in industries and other related areas. Milling like any metal cutting operation is used with an objective of optimizing surface roughness at micro level and economic performance at macro level. In addition to surface finish, modern manufacturers do not want any compromise on the achievement of high quality, dimensional accuracy, high production rate, minimum wear on the cutting tools, cost saving and increase of the performance of the product with minimum environmental hazards. In order to optimize the surface finish, the empirical relationships between input and output variables should be established in order to predict the output. Optimization of these predictive models helps us to select appropriate input variables for achieving the best output performance. In this paper, four input variables are selected and surface roughness is taken as output variable. Particle swarm optimization technique is used for finding the optimum set of values of input variables and the results are compared with those obtained by GA optimization in the literature.

Determination of Na-K-ATPase activity in single segments of the mammalian nephron

1979 ◽  
Vol 237 (2) ◽  
pp. F105-F113 ◽  
Author(s):  
A. Doucet ◽  
A. I. Katz ◽  
F. Morel
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Inorganic Phosphate ◽  
Rapid Freezing ◽  
Phosphate Release ◽  
Large Numbers ◽  
Hydrolysis Of ◽  
Single Tubules

A micromethod for the determination of Na-K-ATPase in discrete segments of nephrons from rabbit, rat, and mouse kidneys is described. To facilitate tubule microdissection, the kidneys were perfused with collagenase after it had been verified that collagenase had no effect on ATPase activity. Individual tubule segments were dissected under stereomicroscopic observation, exposed to a hypotonic environment followed by rapid freezing, and incubated in 1 microliter assay medium. Enzyme activity was determined by direct measurement of labeled inorganic phosphate release by the hydrolysis of [gamma-32P]ATP and was expressed as a function of tubule length. This method is technically simple enough to permit simultaneous measurement of the enzyme in large numbers of tubules and sufficiently sensitive to determine its activity in each region of the nephron. Correlation of Na-K-ATPase activity in single tubules with functional measurements obtained in the corresponding segment of the nephron with the perfused tubule or micropuncture techniques should help define the role of this enzyme in tubular ion transport.

scholarly journals Effects of Reproductive Hormones on Experimental Vaginal Candidiasis

2000 ◽  
Vol 68 (2) ◽  
pp. 651-657 ◽  
Author(s):  
Paul L. Fidel ◽  
Jessica Cutright ◽  
Chad Steele
Keyword(s):  
Experimental Infection ◽  
Reproductive Hormones ◽  
Vaginal Candidiasis ◽  
Delayed Type Hypersensitivity ◽  
Vaginal Infection ◽  
Childbearing Age ◽  
Vaginal Epithelial Cells ◽  
Large Numbers ◽  
Wide Range

ABSTRACT Vulvovaginal candidiasis (VVC) is an opportunistic mucosal infection caused by Candida albicans that affects large numbers of otherwise healthy women of childbearing age. Acute episodes of VVC often occur during pregnancy and during the luteal phase of the menstrual cycle, when levels of progesterone and estrogen are elevated. Although estrogen-dependent experimental rodent models of C. albicans vaginal infection are used for many applications, the role of reproductive hormones and/or their limits in the acquisition of vaginal candidiasis remain unclear. This study examined the effects of estrogen and progesterone on several aspects of an experimental infection together with relative cell-mediated immune responses. Results showed that while decreasing estrogen concentrations eventually influenced infection-induced vaginal titers of C. albicansand rates of infection in inoculated animals, the experimental infection could not be achieved in mice treated with various concentrations of progesterone alone. Furthermore, progesterone had no effect on (i) the induction and persistence of the infection in the presence of estrogen, (ii) delayed-type hypersensitivity in primary-infected mice, or (iii) the partial protection from a secondary vaginal infection under pseudoestrus conditions. Other results with estrogen showed that a persistent infection could be established with a wide range of C. albicans inocula under supraphysiologic and near-physiologic (at estrus) concentrations of estrogen and that vaginal fungus titers or rates of infection were similar if pseudoestrus was initiated several days before or after inoculation. However, the pseudoestrus state had to be maintained for the infection to persist. Finally, estrogen was found to reduce the ability of vaginal epithelial cells to inhibit the growth of C. albicans. These results suggest that estrogen, but not progesterone, is an important factor in hormone-associated susceptibility to C. albicans vaginitis.

scholarly journals Crop Establishment SIMulator: A Qualitative Aggregative Model to Predict the Role of Phytobiomes on Field Crop Establishment

2020 ◽  
Vol 4 (4) ◽  
pp. 327-339 ◽  
Author(s):  
Jay Ram Lamichhane ◽  
Ming Pei You ◽  
Martin J. Barbetti ◽  
Jean-Noël Aubertot
Keyword(s):  
Generic Model ◽  
Field Crop ◽  
State Variables ◽  
Modeling Framework ◽  
Crop Establishment ◽  
Ex Post ◽  
Wide Range ◽  
Input Variables

The definition of phytobiomes can be transposed to any agroecosystem and applies to any phase of crop cycles. Here, we study the crop establishment phase using a generic modeling framework to assess the potential role of phytobiomes on field crop establishment. We first developed a generic model called Crop Establishment SIMulator (CESIM) that takes into account cropping practices, seed and seedling characteristics, seedbed components (physical chemical and biological), and weather, as well as their interactions. All these variables were integrated in a qualitative aggregative hierarchical network to predict the quality of field crop establishment. CESIM has 38 basic (input variables) and 20 aggregated (19 state variables and 1 output variable) attributes for a total of 58 attributes. The prediction quality of the model was evaluated for a dataset of 231 field observations across four states of Australia and experimental results obtained in the last 40 years. Accuracy of predictions of the final attribute (i.e., crop establishment) was 91% and explained 29% of variability of the dataset, as described by the quadratic weighted Cohen’s κ. CESIM represents a unique and original generic model capable of taking into account a large number of variables and their interactions to predict the quality of field crop establishment. This model is flexible, transparent, and user friendly and, therefore, is suitable both for academic and nonacademic users. CESIM can be used across a wide range of situations to perform not only the ex-ante assessment of potential establishment quality of a given crop but also ex-post assessment.

Universities as Incubators without Walls

2002 ◽  
Vol 3 (4) ◽  
pp. 245-256 ◽  
Author(s):  
Andy Lockett ◽  
Ajay Vohora ◽  
Mike Wright
Keyword(s):  
High Technology ◽  
Case Material ◽  
Business Incubators ◽  
Access To Resources ◽  
Business Services ◽  
Large Numbers ◽  
Start Up ◽  
Wide Range ◽  
The University

Interest in the role of business incubators in the development of high-technology start-up companies has increased dramatically in recent years. This interest has led to the creation of large numbers of ‘formal’ incubators, offering a wide range of business services to facilitate the development of the companies located within their walls. The authors argue that this may lead to a neglect of the role universities play in incubating high-technology start-up companies. In this paper the following question is considered: what kind of role can and should universities play in the process without being ‘formal’ incubators? In answering this question the role of the university in providing access to resources is examined. Based on a new survey and case material, the authors' contention is that universities are now performing many of the functions of an incubator. However, they differ from many ‘formal’ incubators in that they do not have clearly defined walls.

Electron Microscopy of Metal-Matrix Composites

1970 ◽  
Vol 28 ◽  
pp. 404-405
Author(s):  
A. Lawley ◽  
M. R. Pinnel ◽  
A. Pattnaik
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Critical Evaluation ◽  
Elastic Behavior ◽  
Matrix Composites ◽  
Directionally Solidified ◽  
Fracture Characteristics ◽  
Broad Program

As part of a broad program on composite materials, the role of the interface on the micromechanics of deformation of metal-matrix composites is being studied. The approach is to correlate elastic behavior, micro and macroyielding, flow, and fracture behavior with associated structural detail (dislocation substructure, fracture characteristics) and stress-state. This provides an understanding of the mode of deformation from an atomistic viewpoint; a critical evaluation can then be made of existing models of composite behavior based on continuum mechanics. This paper covers the electron microscopy (transmission, fractography, scanning microscopy) of two distinct forms of composite material: conventional fiber-reinforced (aluminum-stainless steel) and directionally solidified eutectic alloys (aluminum-copper). In the former, the interface is in the form of a compound and/or solid solution whereas in directionally solidified alloys, the interface consists of a precise crystallographic boundary between the two constituents of the eutectic.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

Sign in / Sign up

Export Citation Format

Share Document