31 research outputs found
A Study of Factors Affecting Liberalization Policies of Jute Industries in Visakhapatnam District
The researcher had made an attempt to evaluate the most influential factor for Work environment, Grievance handling system and Participation management with the impact of liberalization polices on industrial relations by taking twenty two parameter for the jute industry of the sample districts of Visakhapatnam The researcher has personally collected the opinions of the respondents through the structured questionnaire. The collected data are analyzed through KMO test, Factor Analysis, Bivariate Correlation Matrix Reliability test. The Analysis shows that the employees are considering three parameters out of twelve of work environment, two out of five for grievance handling system and also two out of five parameters from participative management.
DOI: 10.17762/ijritcc2321-8169.150518
Level set based eXtended finite element modelling of the response of fibrous networks under hygroscopic swelling
Materials like paper, consisting of a network of natural fibres, exposed to
variations in moisture, undergo changes in geometrical and mechanical
properties. This behaviour is particularly important for understanding the
hygro-mechanical response of sheets of paper in applications like digital
printing. A two-dimensional microstructural model of a fibrous network is
therefore developed to upscale the hygro-expansion of individual fibres,
through their interaction, to the resulting overall expansion of the network.
The fibres are modelled with rectangular shapes and are assumed to be perfectly
bonded where they overlap. For realistic networks the number of bonds is large
and the network is geometrically so complex that discretizing it by
conventional, geometry-conforming, finite elements is cumbersome. The
combination of a level-set and XFEM formalism enables the use of regular,
structured grids in order to model the complex microstructural geometry. In
this approach, the fibres are described implicitly by a level-set function. In
order to represent the fibre boundaries in the fibrous network, an XFEM
discretization is used together with a Heaviside enrichment function. Numerical
results demonstrate that the proposed approach successfully captures the
hygro-expansive properties of the network with fewer degrees of freedom
compared to classical FEM, preserving desired accuracy.Comment: 27 pages, 22 figures, 4 tables, J. Appl. Mech. June 19, 202
Unified model for quasar absorption line systems
We propose a three component model consisting of minihalos and galactic halos
with embedded thin discs for absorbers producing all the observed classes of
intervening quasar absorption line systems. We show that this model, based on
CDM cosmology, can explain most of the observed statistical distributions of
various types of absorption systems. Use of the Schechter luminosity function
for absorbers, on the other hand, is consistent with the observations only if
the number of galaxies was larger in the past and reduced with time due to
mergers. A strong chemical evolution in the halos of galaxies is indicated by
the observed properties of CIV lines. We discuss our results in the light of
the recent observations of the absorption line systems.Comment: 8 pages and 7 figures. Accepted for publication in Astronomy and
Astrophysic
Hydrochemical diversity of semi-natural water system on the background of environmental conditions
Phase selection and fault section identification in thyristor controlled series compensated line using discrete wavelet transform
Discrete wavelet transform is used to analyze faulty signals for a transmission system employing a thyristor controlled series capacitor at the midpoint of a line. Different frequency components of current signals are considered to select the phase(s) involved with a fault. To identify the fault section the new approach utilizes the difference in high frequency components of the current signals. For both phase selection and section identification tasks new energy and standard deviation-based indices are also calculated for the transmission system
Modeling the effect of creep in paper fibres under the influence of external loading and changes in moisture
Paper is a material exhibiting a complex microstructure that is composed of a network of fibres at the micro-level. When subjected to external loading or variations in moisture conditions over different time scales, changes in strain that are non-linear with respect to time are observed at the sheet level (macro-scale). In order to investigate this time-dependent behaviour of paper, a creep power law model is implemented within a finite element approach at the level of single fibres. This rate-dependent model is found to capture experimental results available in literature for single fibres with a good agreement (both quantitatively and qualitatively). Based on the identified model at the level of single fibres, the time-dependent hygro-mechanical response is upscaled towards the network scale. To this end, random model networks of ribbon shaped fibres are generated and their response is simulated. The network-scale response, emerging from the rate-dependent fibre model, demonstrates the ability to predict the response of networks subjected to relaxation at a constant moisture level. The developed numerical model predicts lower values of overall stress response in single fibres as compared to networks. Also, stress relaxation predicted by the rate-dependent model in the cross-direction of the networks is in agreement with the experimental observations by Johanson and Kubát (1967). Therefore, one of the remarkable findings of the present work is that the developed rate-dependent model is robust enough to capture the sheet scale response also qualitatively. Based on the study of these computational results, a better understanding is achieved regarding the influence of mechanical and rate-dependent properties of single fibres on the hygro-expansion of complete fibre networks, and in particular of paper sheets
Micro-mechanical modeling of irreversible hygroscopic strain in paper sheets exposed to moisture cycles
Paper is a complex material consisting of a network of cellulose fibres at the micro-level. During manufacturing, the network is dried under restraint conditions due to tension in the paper web in machine direction. This gives rise to internal strains that are stored in the produced sheet. Upon exposure to a moisture cycle, these strains may be released. This results in permanent shrinkage that may cause instabilities such as curl or waviness of the sheet. The prime objective of this paper is to model this irreversible shrinkage and to link its magnitude to the properties of the fibres and of the network. For this purpose, randomly generated fibrous networks of different coverages (i.e. ratio of the area occupied by fibres and that of the sheet) are modeled by means of a periodic representative volume element (RVE). Within such RVEs, a finite element method combined with a kinematic hardening plasticity model at the scale of the fibres is used to capture the irreversible response. The computational results obtained demonstrate that the magnitude of the irreversible strains increases with coverage until a certain coverage and beyond that coverage decreases in magnitude. This phenomenon is explained by considering the area fraction of free-standing fibre segments relative to bonded fibre segments in the network. A structure–property dependency of irreversible strains at the sheet-level on the micro-structural parameters of the network is thereby established