247 research outputs found
Modeling and simulation of film blowing process
Film blowing process is a flexible mass production technology used for manufacturing
thin polymeric films. Its flexibility in using an existing die to produce films
of different width and thickness, just by controlling process conditions such as, extrudate
velocity, excess pressure, and line speed, makes it an attractive process with
less capital investment. Controlling the process conditions to obtain a stable bubble,
however, is not a trivial task. It is a costly trial and error procedure, which could
result is a large wastage of material and other resources. Hence, it is necessary to
develop methods to simulate the process and design it using numerical experiments.
This important need of the industry defines the objective of this work. In this dissertation,
a transient, axisymmetric, nonisothermal, viscoelastic model is developed
to simulate the process, and it is solved using finite element method. Material behavior
of polymer melt is described using a modified Phan-Thien-Tanner model in
the liquid??like region, and anisotropic Kelvin??Voight model in the solid zone, and
the transition is modeled using a simple mixture theory. Crystallization kinetics is
described using a modified Avrami model with factors to account for the influence
of temperature and strain. Results obtained are compared with available experimental
results and the model is used to explore stability issues and the role of different
parameters. Software developed using this model comes with a GUI based pre- and
post-processor, and it can be easily adapted to use other constitutive models
Modeling and simulation of film blowing process
Film blowing process is a flexible mass production technology used for manufacturing
thin polymeric films. Its flexibility in using an existing die to produce films
of different width and thickness, just by controlling process conditions such as, extrudate
velocity, excess pressure, and line speed, makes it an attractive process with
less capital investment. Controlling the process conditions to obtain a stable bubble,
however, is not a trivial task. It is a costly trial and error procedure, which could
result is a large wastage of material and other resources. Hence, it is necessary to
develop methods to simulate the process and design it using numerical experiments.
This important need of the industry defines the objective of this work. In this dissertation,
a transient, axisymmetric, nonisothermal, viscoelastic model is developed
to simulate the process, and it is solved using finite element method. Material behavior
of polymer melt is described using a modified Phan-Thien-Tanner model in
the liquid??like region, and anisotropic Kelvin??Voight model in the solid zone, and
the transition is modeled using a simple mixture theory. Crystallization kinetics is
described using a modified Avrami model with factors to account for the influence
of temperature and strain. Results obtained are compared with available experimental
results and the model is used to explore stability issues and the role of different
parameters. Software developed using this model comes with a GUI based pre- and
post-processor, and it can be easily adapted to use other constitutive models
Wireless strain sensing system for assessing condition of civil infrastructure facilities
Bežični senzori i senzorske mreže postaju zamjena za tradicionalne sustave za praćenje ponašanja konstrukcija. Njihova je prednost u nižoj cijeni ugradnje jer nema potrebe za polaganjem dugih kabela između senzora i sustava za prikupljanje podataka. U radu se opisuju istraživanja provedena u svrhu ocjenjivanja učinkovitosti bežičnih senzora za mjerenje relativnih deformacija. Dan je primjer primjene bežičnog senzorskog sustava pri mjerenju ponašanja konstrukcije željezničkog mosta te je napravljena usporedba s primjenom klasičnih sustava.Wireless sensors and sensor networks are emerging as substitutes for traditional structural monitoring systems. Their benefit lies in a lower cost of installation because extensive wiring is no longer required between sensors and the data acquisition system. Studies carried out to evaluate performance of wireless strain measurement units are described in this paper. An example is given of a wireless system used for measuring behaviour of a railway bridge, and comparison with traditional systems is made
Spectrum and quench-induced dynamics of spin-orbit coupled quantum droplets
We investigate the ground state and dynamics of one-dimensional spin-orbit
coupled (SOC) quantum droplets within the extended Gross-Pitaevskii approach.
As the SOC wavenumber increases, stripe droplet patterns emerge, with a
flat-top background, for larger particle numbers. The surface energy decays
following a power-law with respect to the interactions. At small SOC
wavenumbers, a transition from Gaussian to flat-top droplets occurs for either
a larger number of atoms or reduced intercomponent attraction. The excitation
spectrum shows that droplets for relatively small SOC wavenumbers are stable,
otherwise stripe droplets feature instabilities as a function of the particle
number or the interactions. We also witness rich droplet dynamical features
using velocity imprinting and abrupt changes in the intercomponent interaction
or the SOC parameters. Characteristic responses include breathing oscillations,
expansion, symmetric and asymmetric droplet fragmentation, admixtures of single
and stripe droplet branches, and erratic spatial distributions suggesting the
triggering of relevant instabilities. Our results reveal the controlled
dynamical generation and stability properties of stripe droplets that should be
detectable in current cold-atom experiments.Comment: 18pages, 13figure
COMPARATIVE DOCKING STUDIES ON THE EFFECT OF COMMERCIAL DRUGS ON DIPEPTIDYL PEPTIDASE-4 (DPP-4)
Objective: The aim of our study was to validate the accuracy of computational tools in drug discovery and molecular interaction studies by studying the inhibitory activity of various commercial drugs on DPP-4.Methods: In order to validate the accuracy of computational tools, 50 commercially available drugs were docked with DPP-4, a major target for type 2 diabetes treatment. Studies were performed using Discovery studio 3.5.Results: The analysis showed that out of the fifty selected drugs, 33 drugs passed the Lipinski's rule and commercially prescribed drugs namely Sulfonylurea, Pregabalin and Metaformin were found to have maximum interaction with the target.Conclusion: These major drugs which yielded the best results were found to be used in the treatment of diabetes which reconfirms the efficacy of these drugs, druggability of the target as well as the accuracy of the tool used
Development of CMAS Resistant Thermal Barrier Coatings: Challenges and Implications
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Intelligent Financial Fraud Detection Practices: An Investigation
Financial fraud is an issue with far reaching consequences in the finance
industry, government, corporate sectors, and for ordinary consumers. Increasing
dependence on new technologies such as cloud and mobile computing in recent
years has compounded the problem. Traditional methods of detection involve
extensive use of auditing, where a trained individual manually observes reports
or transactions in an attempt to discover fraudulent behaviour. This method is
not only time consuming, expensive and inaccurate, but in the age of big data
it is also impractical. Not surprisingly, financial institutions have turned to
automated processes using statistical and computational methods. This paper
presents a comprehensive investigation on financial fraud detection practices
using such data mining methods, with a particular focus on computational
intelligence-based techniques. Classification of the practices based on key
aspects such as detection algorithm used, fraud type investigated, and success
rate have been covered. Issues and challenges associated with the current
practices and potential future direction of research have also been identified.Comment: Proceedings of the 10th International Conference on Security and
Privacy in Communication Networks (SecureComm 2014
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