National Institute of Technology, Karnataka

About: National Institute of Technology, Karnataka is a education organization based out in Mangalore, Karnataka, India. It is known for research contribution in the topics: Corrosion & Cloud computing. The organization has 5017 authors who have published 7057 publications receiving 70367 citations.

Bio-inspired, fouling resistant, tannic acid functionalized halloysite nanotube reinforced polysulfone loose nanofiltration hollow fiber membranes for efficient dye and salt separation

Abstract: Superficial functionalization of the hollow fiber membrane with progressive nanomaterials exhibits increased hydrophilicity, outstanding selectivity, and permeability. In the present study, a simple and novel loose nanofiltration (NF) membranes were prepared by the addition of tannic acid functionalized halloysite nanotubes (THNTs) in polysulfone (PSf) membrane matrix via phase inversion method. The successful modification of halloysite (HNTs) was confirmed by FT-IR, zeta potential measurement, TGA, TEM and EDX analysis. The membrane permeation studies were carried out with a sequence of salts (NaCl and Na2SO4) and dyes (reactive black 5 and reactive orange 16). The resulted membranes exhibited increased hydrophilicity, porosity, water uptake, antifouling performance, along with higher dye rejection (>99% for reactive black 5 and >90% of reactive orange 16) and low salt rejection (2.5% of NaCl and 7.5% of Na2SO4) properties. The nanocomposite membrane also exhibited the highest pure water flux of 92 L/m2 h compared to the pristine membrane of 18 L/m2 h made it a worthy candidate for the wastewater purification.

Automated Method for Retinal Artery/Vein Separation via Graph Search Metaheuristic Approach

Abstract: Separation of the vascular tree into arteries and veins is a fundamental prerequisite in the automatic diagnosis of retinal biomarkers associated with systemic and neurodegenerative diseases. In this paper, we present a novel graph search metaheuristic approach for automatic separation of arteries/veins (A/V) from color fundus images. Our method exploits local information to disentangle the complex vascular tree into multiple subtrees, and global information to label these vessel subtrees into arteries and veins. Given a binary vessel map, a graph representation of the vascular network is constructed representing the topological and spatial connectivity of the vascular structures. Based on the anatomical uniqueness at vessel crossing and branching points, the vascular tree is split into multiple subtrees containing arteries and veins. Finally, the identified vessel subtrees are labeled with A/V based on a set of hand-crafted features trained with random forest classifier. The proposed method has been tested on four different publicly available retinal datasets with an average accuracy of 94.7%, 93.2%, 96.8%, and 90.2% across AV-DRIVE, CT-DRIVE, INSPIRE-AVR, and WIDE datasets, respectively. These results demonstrate the superiority of our proposed approach in outperforming the state-of-the-art methods for A/V separation.

A Triband Circularly Polarized Strip and SRR-Loaded Slot Antenna

Abstract: In this communication, a simple and compact multiband circularly polarized (CP) slot antenna loaded with metallic strips and a split-ring resonator (SRR) is proposed. The multiband operation is obtained via exciting the SRR and copper strips by the microstrip-fed square slot antenna. The SRR resonates at 1.83 GHz, while the strips and the slot antenna provide resonances at 2.5 and 3.1 GHz. Resonant modes of loaded SRR and strips combined with the fundamental mode of the slot produce CP waves at the resonance frequencies of the proposed antenna. The proposed antenna allows for independent tuning of different bands via the use of the tilted strips and the SRR. Also, the sense of polarization at the resonance frequencies can be controlled by changing the orientation of the strips and the SRR with respect to the slot. The proposed antenna is fabricated on an FR-4 substrate of dimension $50 \times 50 \times 1.56$ mm3. Antenna performances in terms of 10 dB return loss bandwidth, 3 dB axial ratio bandwidth, gain, and efficiency are validated experimentally and are in a good agreement with the simulated results.