High performance polyaniline containing coating system for wet surfaces

Application of paint coatings on wet surfaces is rather difficult due to poor adhesion of coatings. For painting of wet surfaces, moisture curable coating systems based on epoxy resin and ketimine are found to be useful. Hence a study has been made on the corrosion protection ability of coating on wet surfaces using epoxy resin, ketimine and polyaniline. Paints with 20–30% PVC were prepared and applied over the wet steel surface and the corrosion protection performance of the coating was found out by salt spray and electrochemical impedance spectroscopic techniques. Coating with 20% PVC is found to offer very high protection since the impedance values are remained at greater than 10⁹ Ω cm² after immersion and salt spray tests.     

Orientation effect on sign and magnitude of excess thermodynamic functions of non electrolyte solutions at different temperatures (303.15 K, 308.15 K,and 313.15K)

Experimental values of the density and viscosity have been measured for binary mixtures of N-ethylaniline with isomeric butanols (1-butanol, 2-butanol, 2-methyl-1-propanol and 2-methyl-2-propanol) at 303.15, 308.15 and 313.15 K over the entire mole fraction range. These data, the excess molar volumes, and deviation viscosity for the binary systems at the above-mentioned temperatures were calculated and fitted to Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. The excess molar volumes, deviation viscosity and excess Gibbs energy of activation of viscous flow have been analyzed in terms of acid-base interactions, hydrogen bond, and dipole-dipole interaction between unlike molecules. The results obtained for dynamic viscosity of binary mixtures were used to test the semi-empirical relations of Grunberg-Nissan, Katti-Chaudhri, and Hind et al. equations.     

Topological refinement procedures for triangular finite element meshes

This paper presents a topological approach to improve the quality of unstructured triangular finite element meshes. Topological improvement procedures are presented both for elements that are interior to the mesh and for elements connected to the boundary. Optimal ordering of the topology improvement operations and their efficient implementation is also discussed. Several example meshes are included to demonstrate the effectiveness of the approach in improving element quality in a finite element mesh.     

Benign Approach of Plant-Derived Inhibitor: Assessing Their Anticorrosive Activity on Mild Steel in Acidic Media

Journal of Failure Analysis and Prevention - The dissolution behavior of mild steel in 2 M H2SO4 with various concentrations of Borassus Flabellifer Seed Food (BFSF), Musa Paradisiaca Dry...     

Design of all-optical AND,OR, and XOR logic gates using photonic crystals for switching applications

Photonic Network Communications - We propose a photonic crystal-based all-optical AND, OR, and XOR logic gates using square lattice silicon rods with air background. The design of proposed logic...     

Analysis of occupation time of vehicles at urban unsignalized intersections in non-lane-based mixed traffic conditions

In India, traffic flow on roads is highly mixed in nature with wide variations in the static and dynamic characteristics of vehicles. At unsignalized intersections, vehicles generally do not follow lane discipline and ignore the rules of priority. Drivers generally become more aggressive and tend to cross the uncontrolled intersections without considering the conflicting traffic. All these conditions cause a very complex traffic situation at unsignalized intersections which have a great impact on the capacity and performance of traffic intersections. A new method called additive conflict flow (ACF) method is suitable to determine the capacity of unsignalized intersections in non-lane-based mixed traffic conditions as prevailing in India. Occupation time is the key parameter for ACF method, which is defined as the time spent by a vehicle in the conflict area at the intersection. Data for this study were collected at two three-legged unsignalized intersections (one is uncontrolled and other one is semicontrolled) in Mangalore city, India using video-graphic technique during peak periods on three consecutive week days. The occupation time of vehicles at these intersections were studied and compared. The data on conflicting traffic volume and occupation time by each subject vehicle at the conflict area were extracted from the videos using image processing software. The subject vehicles were divided into three categories: two wheelers, cars, and auto-rickshaws. Mathematical relationships were developed to relate the occupation time of different categories of vehicles with the conflicting flow of vehicles for various movements at both the intersections. It was found that occupation time increases with the increasing conflicting traffic and observed to be higher at the uncontrolled intersection compared to the semicontrolled intersection. The segregated turning movements and the presence of mini roundabout at the semicontrolled intersection reduces the conflicts of vehicular movements, which ultimately reduces the occupation time. The proposed methodology will be useful to determine the occupation time for various movements at unsignalized intersections. The models developed in the study can be used by practitioners and traffic engineers to estimate the capacity of unsignalized intersections in non-lane-based discipline and mixed traffic conditions.

     

Corrosion protective performance studies of coating systems in soda ash chemical industry

Organic coatings are widely used to protect steel structures. The performance of the coating system depends upon the atmospheric conditions prevailing in the chemical industry. Before selecting a protective system, the corrosivity of the atmosphere has to be determined. A study has been made for selecting a good protective system for a soda ash chemical industry where chemicals such as soda ash, sodium chloride and hydrochloric acid are produced by using sea water as a raw material. Under these conditions, after collecting the corrosivity rate at various places of industrial areas, coated steel panels with various paint combinations were exposed in different sites for a period of 2 years. The performance of the coatings was monitored by EIS studies besides visual inspection. The corrosion protection performance of the various coating systems of zinc rich primer with different types of under coats and top coats has been studied and the results are reported.     

The Graham-Knowlton Problem Revisited

In the late 60s Graham and Knowlton introduced the WIP (wire identification problem) that affected electricians: match the wires in the ceiling to those in the basement while making the fewest trips. We revisit this problem and study its variants and generalizations; we provide a combinatorial characterization of the solution(s) in terms of an associated hypergraph and obtain nearly tight bounds on the minimum number of trips.