Journal of Engineering Research

Understanding of particle motion through water and the particle sedimentation as well as distribution mechanism in an open channel flow is of considerable engineering importance. In an effort to test the extent to which fundamental fluid mechanics can provide a prediction of particle concentration profile and the fluid velocity profile, a study on a simple inclined rectangular channel has been carried out using glass bead and ilmenite mixtures at various particle concentrations and flow rates. Great care was taken to devise a flow splitter at the end of the channel that permitted accurate measurement of the fluid flow profile and collection of slurry samples, allowing evaluation of the particle species concentration profiles for model validation purpose. The resulting predictions of particle separation are shown to be a strong function of the settling velocities of the particles used and the resulting predictions of particle separation are remarkably good, which ultimately validates the modelling methodology.

Protection of medical image content is more significant in telemedicine. Digital lossless watermarking becomes the auspicious technique to secure the medical content in medical images. To enhance the security, this paper suggests secure hash algorithm , rivest- shamir- adlemen algorithm, novel algorithms additive hash function and advanced classical cipher for replacing the existing algorithm and the production of digital signature to achieve high confidentiality and authentication. An image is compressed using joint photographic experts group JPEG 2000 discrete wavelet transforms for region of interest and joint photographic experts group JPEG for region of non interest. The medical image content electronics patient record and digital signature is embedded in region of non interest of compressed image, using lossless watermarking technique. Watermarking technique increases the integrity and authenticity, when medical images are shared through open network. The peak signal to noise ratio value is up to 72dBs for all types of digital imaging and communications in medicine images. Increase in authentication can be achieved when the medical expert access secured medical images from the web servers using Kerberos technique.

The paper proposes an efficient watermarking scheme by incorporating singular value decomposition (SVD), discrete cosine transform (DCT) and homogeneity information in the carrier image. The algorithm decomposes the carrier and watermark images into non-overlapping blocks and analyzes the homogeneity of pixels in them to identify the possible blocks of carrier image where the suitable watermark block can be attached so that the watermarking process maintain better visual image fidelity in the watermarked image. The algorithm avoids the decomposed high frequency carrier image blocks while attaching watermark blocks to reduce the visual distortion in the watermarked images. Experimental results show that the proposed algorithm produces good quality watermarked images and are less immune to potential attacks.