The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform

David Hayward - One of the best experts on this subject based on the ideXlab platform.

  • permeability of n2 ar he o2 and co2 through biaxially Oriented Polyester films dependence on free volume
    Polymer, 2001
    Co-Authors: E A Mcgonigle, J J Ligga, Richard A Pethrick, Stephe D Jenkins, J H Daly, David Hayward
    Abstract:

    Permeability, diffusion and solubility coefficients are reported for biaxially orientated Polyester films based on poly(ethylene terephthalate) [PET], poly(ethylene naphthalate) [PEN] and copolymers containing PET and PEN moieties. Data for cast amorphous sheets and materials produced with different biaxial draw ratios are compared. The crystallinity of the samples was assessed using differential scanning calorimetry and density measurements. The changes in the void structure at a molecular level were investigated using positron annihilation lifetime spectroscopy (PALS). The variation of the gas diffusion behaviour with the gas used (carbon dioxide, nitrogen, argon, helium and oxygen) reflects the effects of change in morphology on the solubility and diffusivity components of the permeability. The diffusivity of the gas is influenced not only by both the changes in the void size and content at a molecular level, but also by the effects of crystallinity on the percolation behaviour of the gas through the matrix. Changes in the extent of chain alignment also have a profound affect on the solubility of the gas in the matrix. The observed behaviour for the gas permeation can be interpreted as being the result of the complex interplay of changes in the crystalline content, the polymer chain alignment and the void structure of the amorphous phase.

E A Mcgonigle - One of the best experts on this subject based on the ideXlab platform.

  • permeability of n2 ar he o2 and co2 through biaxially Oriented Polyester films dependence on free volume
    Polymer, 2001
    Co-Authors: E A Mcgonigle, J J Ligga, Richard A Pethrick, Stephe D Jenkins, J H Daly, David Hayward
    Abstract:

    Permeability, diffusion and solubility coefficients are reported for biaxially orientated Polyester films based on poly(ethylene terephthalate) [PET], poly(ethylene naphthalate) [PEN] and copolymers containing PET and PEN moieties. Data for cast amorphous sheets and materials produced with different biaxial draw ratios are compared. The crystallinity of the samples was assessed using differential scanning calorimetry and density measurements. The changes in the void structure at a molecular level were investigated using positron annihilation lifetime spectroscopy (PALS). The variation of the gas diffusion behaviour with the gas used (carbon dioxide, nitrogen, argon, helium and oxygen) reflects the effects of change in morphology on the solubility and diffusivity components of the permeability. The diffusivity of the gas is influenced not only by both the changes in the void size and content at a molecular level, but also by the effects of crystallinity on the percolation behaviour of the gas through the matrix. Changes in the extent of chain alignment also have a profound affect on the solubility of the gas in the matrix. The observed behaviour for the gas permeation can be interpreted as being the result of the complex interplay of changes in the crystalline content, the polymer chain alignment and the void structure of the amorphous phase.

Kuvvetli Y. - One of the best experts on this subject based on the ideXlab platform.

  • Predicting the intermingled yarn number of nips and nips stability with neural network models
    National Institute of Science Communication and Information Resources (NISCAIR), 2015
    Co-Authors: Özka İ., Kuvvetli Y., Aykal P.d., Sahi C.
    Abstract:

    This study aims at predicting the effects of selected process parameters on nips stability and number of nips by using different artificial intelligence methods. Partially Oriented Polyester yarn with 283 dtex linear density and different numbers of filaments are intermingled with different speed and pressure levels. The feed forward neural network with multi-hidden layers (ML-FFNN) and general regression neural networks (GRNN) have been selected as artificial intelligence methods. The number of filaments, intermingling speed and pressure values are used as input variables on the artificial neural networks. The effects of number of hidden layers on the ML-FFNN and number of nodes in the hidden layer are investigated. Based on comparative results, the ML-FFNN is found to give better performance (at most 6%) than by GRNN in terms of prediction accuracy on train and test data sets. It can be concluded from this study that the neural networks has great ability to predict intermingling process parameters. © 2015, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved

  • Comparison of the neural network model and linear regression model for predicting the intermingled yarn breaking strength and elongation
    'Informa UK Limited', 2014
    Co-Authors: Kuvvetli Y., Duru Baykal P., Erol R.
    Abstract:

    In this study, the effects of selected intermingling process parameters on yarn breaking strength and elongation were predicted using artificial neural network. For this aim, partially Oriented Polyester yarn with 283 dtex linear density and three different numbers of filaments (34, 68, and 100) were used for producing interlaced yarn under different process parameters (speed and pressure). Yarns' elongation and strength values measured with Uster Tensorapid test device and the number of filaments are input variables of the artificial neural networks. Feed forward neural network (FFNN) is used as the network structure. All FFNN computations were performed by MATLAB software package. The comparison results show that the FFNN has a better prediction performance than linear regression. © 2014 © 2013 The Textile Institute

Hendra Suryadharma - One of the best experts on this subject based on the ideXlab platform.

  • Perilaku Geser Tanah yang Distabilisasi dengan Abu Ampas Tebu-Semen dan Inklusi Serat Polyester
    Universitas Diponegoro, 2017
    Co-Authors: John Tri Hatmoko, Hendra Suryadharma
    Abstract:

    Bagasse ash is a fine residue collected from the burning of bagasse in sugar factory, and it behaves as pozzolanic materials. In addition, engineering behaviour of bagasse ash can be improved by addition of cement containing high calcium. Recently, research about cement stabilized soil is continuously in progress. In this paper, a set of experiment programs were done to investigate the randomly Oriented Polyester fibre  inclusion in bagasse ash-cement stabilized soil.  Bagasse ash was mixed with clay in different proportions. To get the optimum curing period,  it was done light compaction test of soil with 8% cement cured with 7, 14, 21, 28 and 36 days curing period,  that was found on 28 days. The next experiment was compaction test on soil + 8% cement + 3,6,9 and 12% bagasse ash to obtain optimum bagasse ash proportion. The result indicated that optimum bagasse ash content was 9%. To ensure this result, unconfined compression test was done on the same sample. Finally, light compaction, unconfined compression and direct shear tests were done on : soil + 8% cement + 9% bagasse ash +  Polyester fibre with 28 days curing period. The results showed that maximum dry density and optimum moisture content was not influenced by fibre inclusion, whereas the increase of shear strength of stabilized soil with fibre inclusion  was mainly due to improvement of internal friction angle. In unconfined compression test, the unconfined compression strength of stabilized soil was significantly improved by fibre inclusion

Suryadharma Y. Hendra - One of the best experts on this subject based on the ideXlab platform.

  • Perilaku Geser Tanah yang Distabilisasi dengan Abu Ampas Tebu Semen dan Inklusi Serat Polyester
    Universitas Diponegoro, 2017
    Co-Authors: Hatmoko, Joh Tri, Suryadharma Y. Hendra
    Abstract:

    A set of experiment programs were done to investigate the randomly Oriented Polyester fibre inclusion in bagasse ash-cement stabilized soil. Bagasse ash was mixed with clay in different proportions. To get the optimum curing period, it was done light compaction test of soil with 8% cement cured with 7, 14, 21, 28 and 36 days curing period, that was found on 28 days. The next experiment was compaction test on soil + 8% cement + 3, 6, 9 and 12% bagasse ash to obtain optimum bagasse ash proportion. The result indicated that optimum bagasse ash content was 9%. To ensure this result, unconfined compression test was done on the same sample. Finally, light compaction, unconfined compression and direct shear tests were done on: soil +8% cement + 9% bagasse ash + Polyester fibre with 28 days curing period. The results showed that maximum dry density and optimum moisture content was not influenced by fibre inclusion, whereas the increase of shear strength of stabilized soil with fibre inclusion was mainly due to improvement of internal friction angle. In unconfined compression test, the unconfined compression strength of stabilized soil was significantly improved by fibre inclusion