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This paper provides an in depth discussion on the titanium dioxide photocatalysis for the treatment of pulp and paper industry wastewater. The mechanism behind TiO₂ photocatalysis, various reaction variables and application of TiO₂ photocatalysis for the remediation of pulp and paper mill wastewater are discussed. TiO2 photocatalysis can cause rapid and complete degradation of nearly all electron rich organic compounds. It involves in situ generation of very reactive non-selective oxidizing species i.e. OH- radicals. Some laboratory experiments were performed to study the effect of catalyst dose and reaction time on the photodegradation efficiency. Paper mill wastewater was treated with UV/TiO₂ process at pH 7 in a slurry type of reactor under artificial UV light. The catalyst dose (0.25 to 1.50 g/L) and reaction time (0.50 to 8.0 h) were varied for studying their effect on the degradation efficiency. The degradation efficiency was measured in terms of percent reduction in COD and colour of the wastewater. Up to 0.75 g/L of TiO₂ the degradation efficiency increased but beyond this it decreased. The degradation rate during the first hour of treatment was very fast. After 4 h of treatment the degradation efficiency became more or less constant and there was no significant increase. The optimum results were obtained at a TiO₂ dose of 0.75 g/L and reaction time of 4 h.

Keywords

Pulp & Paper Industry, Titanium Dioxide (TiO₂), Heterogeneous Photocatalysis, Wastewater Treatment, AOP's

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Face Recognition using Symmetric Local Graph Structure

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Authors

Movina R. Ayoob ¹, R. Mathusoothana ¹, S. Kumar ¹

Affiliations
1 Noorul Islam University, kumaracoil, Kanyakumari - 629180, Tamil Nadu, IN

Source

Indian Journal of Science and Technology, Vol 8, No 24 (2015), Pagination:

Abstract

Biometrics is the process of making use of physical, biological and behavioral traits for identification purposes. Biometrics finds applications in wide variety of fields such as security, access control, and military. Among the various kinds of biometrics, face biometrics is one among the fast growing biometrics due to its flexibility in usage and easy availability of equipments. This work is focused on the area of face biometrics, which incorporates the concept of image processing along with it. The proposed work is aimed to determine the recognition accuracy of face recognition technique and compare its accuracy with existing techniques and also addresses the problems related to facial details, illumination and facial expressions in face recognition. This work shows the higher and gradual increase in accuracy of face recognition and enables to implement wide variety of applications in computer vision using standard face databases.

Keywords

Discrete Cosine Transform, Gabor Filter, Local Binary Pattern, Symmetric Local Graph Structure

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