Accelerated Short-Term Techniques to Evaluate Corrosion in TiC Reinforced AA6063 Composites

AA6063-TiC composites have several weight percentages up to 9 wt. % were fabricated by using stir casting route method. The effects of the weight percentage of TiC particles on the microstructures and corrosion behavior of AA6063-TiC composites were studied. The results revealed that the AA6063-TiC composites exhibited higher density than the AA6063 matrix. The accelerated corrosion tests of AA6063-TiC composites in 3.5 wt. % NaCl aqueous solution at room temperature, the AA6063-TiC composites have better corrosion resistance than the AA6063 matrix. Increasing the weight percentage of the TiC particles to reduces the corrosion rate of the AA6063-TiC composites. In this process corrosion rate of 0.4402 mm/year for AA6063 matrix, 0.3891 mm/year for 3 wt. % , 0.3568 mm/year for 6 wt. % and 0.3062 mm/year for 9 wt. % of TiC particles respectively. The poor corrosion resistance of the composites can be attributed to the galvanic effects between the AA6063 matrix and TiC reinforcement

Road Network Mix-zones for Anonymous Location Based Services

Abstract-We present MobiMix, a road network based mix-zone framework to protect location privacy of mobile users traveling on road networks. An alternative and complementary approach to spatial cloaking based location privacy protection is to break the continuity of location exposure by introducing techniques, such as mix-zones, where no applications can trace user movements. However, existing mixzone proposals fail to provide effective mix-zone construction and placement algorithms that are resilient to timing and transition attacks. In MobiMix, mix-zones are constructed and placed by carefully taking into consideration of multiple factors, such as the geometry of the zones, the statistical behavior of the user population, the spatial constraints on movement patterns of the users, and the temporal and spatial resolution of the location exposure. In this demonstration, we first introduce a visualization of the location privacy risks of mobile users traveling on road networks and show how mixzone based anonymization breaks the continuity of location exposure to protect user location privacy. We demonstrate a suite of road network mix-zone construction and placement methods that provide higher level of resilience to timing and transition attacks on road networks. We show the effectiveness of the MobiMix approach through detailed visualization using traces produced by GTMobiSim on different scales of geographic maps

Monitoring of Multi-Aspect Drought Severity and Socio-Economic Status in the Semi-Arid Regions of Eastern Tamil Nadu, India

A framework was set up to monitor drought in the semi-arid regions of eastern Tamil Nadu, southern India, for the period of 2014–2018 CE with the application of the standardized precipitation index (SPI), the scaled drought-condition index (SDCI), and the standardized water-level index (SWI). The results emphasized that this region had a negative precipitation anomaly and vegetative stress, both of which triggered meteorological and agricultural droughts and caused significant losses in the farming sector. The distributions of extreme and high-level hydrological droughts were at their maximum in 2017 CE. The multi-drought severity index (MDSI), implemented to assess the combined impact and highlighting the gradient of affected areas, illustrated that the eastern region (i.e., Jayankondam block) was the most extremely affected, followed by the northern and southern regions (i.e., T.Palur and Andimadam), which were moderately affected by droughts. The extremely affected eastern region has less of an ability to overcome droughts due to its socio-economic vulnerability, with its greater population and household density leading to the over-exploitation of potential resources. Therefore, the focus of this study is on the monitoring of drought severity in micro-administrative units to suggest an appropriate management plan. Hence, the extreme-drought- prone block (Jayankondam) should be given high priority in monitoring and implementing long-term management practices for its conservation and resilience against the effects of severe droughts

Improving the corrosion resistance and bioactivity of magnesium by a carbonate conversion-polycaprolactone duplex coating approach

Decreasing the rate of degradation of Mg has been the focus of developing various types of coatings for Mg. Though polycaprolactone (PCL) coating is capable of providing short-term improvement in corrosion resistance for Mg, the porous nature of the PCL coating and the inside out corrosion of Mg have led to cracking and delamination of the PCL coating. Poor adhesion of the PCL coating on Mg is another limitation. To overcome these limitations, the present study aims to explore magnesium carbonate coating as a pre-treatment. The study proposes a duplex coating approach, which involves deposition of magnesium carbonate by a chemical conversion method as the first layer over which a PCL coating is formed by the dip coating method. The morphological features, nature of functional groups, phase content, adhesive strength, etc., of the magnesium carbonate and duplex coating were evaluated by using scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction measurement and tensile testing, respectively. The corrosion behaviour of the magnesium carbonate and duplex coating in Hanks' solution was evaluated by using potentiodynamic polarization, electrochemical impedance spectroscopy and immersion tests. The bioactivity of the magnesium carbonate and duplex coating was evaluated by immersing them in simulated body fluid. The extent of apatite growth served as a measure of their bioactivity. The study reveals that MgCO3 coating served as an excellent base for the deposition of the PCL layer and the duplex coating offered a good corrosion resistance in Hanks' solution and exhibited better bioactivity in simulated body fluid. The study concludes that the magnesium carbonate-PCL duplex coating is a viable approach to reduce the rate of corrosion of magnesium and to improve its bioactivity

Biopolymer and Synthetic Polymer-Based Nanocomposites in Wound Dressing Applications: A Review

Biopolymers are materials obtained from a natural origin, such as plants, animals, microorganisms, or other living beings; they are flexible, elastic, or fibrous materials. Polysaccharides and proteins are some of the natural polymers that are widely used in wound dressing applications. In this review paper, we will provide an overview of biopolymers and synthetic polymer-based nanocomposites, which have promising applications in the biomedical research field, such as wound dressings, wound healing, tissue engineering, drug delivery, and medical implants. Since these polymers have intrinsic biocompatibility, low immunogenicity, non-toxicity, and biodegradable properties, they can be used for various clinical applications. The significant advancements in materials research, drug development, nanotechnology, and biotechnology have laid the foundation for changing the biopolymeric structural and functional properties. The properties of biopolymer and synthetic polymers were modified by blending them with nanoparticles, so that these materials can be used as a wound dressing application. Recent wound care issues, such as tissue repairs, scarless healing, and lost tissue integrity, can be treated with blended polymers. Currently, researchers are focusing on metal/metal oxide nanomaterials such as zinc oxide (ZnO), cerium oxide (CeO2), silver (Ag), titanium oxide (TiO2), iron oxide (Fe2O3), and other materials (graphene and carbon nanotubes (CNT)). These materials have good antimicrobial properties, as well as action as antibacterial agents. Due to the highly antimicrobial properties of the metal/metal oxide materials, they can be used for wound dressing applications

A mini review on immune role of chemokines and its receptors in snakehead murrel Channa striatus

Chemokines are ubiquitous cytokine molecules involved in migration of cells during inflammation and normal physiological processes. Though the study on chemokines in mammalian species like humans have been extensively studied, characterization of chemokines in teleost fishes is still in the early stage. The present review provides an overview of chemokines and its receptors in a teleost fish, Channa striatus. C. striatus is an air breathing freshwater carnivore, which has enormous economic importance. This species is affected by an oomycete fungus, Aphanomyces invadans and a Gram negative bacteria Aeromonas hydrophila is known to cause secondary infection. These pathogens impose immune changes in the host organism, which in turn mounts several immune responses. Of these, the role of cytokines in the immune response is immense, due to their involvement in several activities of inflammation such as cell trafficking to the site of inflammation and antigen presentation. Given that importance, chemokines in fishes do have significant role in the immunological and other physiological functions of the organism, hence there is a need to understand the characteristics, activities and performace of these small molecules in details