Mitigation of ammonia-induced SCC in a cupronickel alloy by additions of MgCl<Subscript>2</Subscript>

The work presented in Part 1 of this article showed that additions of magnesium chloride (MgCl₂) to ammonia solutions reduced the tendency of ammonia-induced stress-corrosion cracking (SCC) initiation in a Cu-5%Ni alloy. The present work was undertaken to study the SCC behavior of the test alloy exposed to ammonia in the presence of varying concentrations of MgCl₂. The exposure to MgCl₂ additions reduced the severity of the ammonia-induced SCC.     

Copyright protection using KELM-PSO based multi-spectral image watermarking in DCT domain with local texture information based selection

Multimedia Tools and Applications - Since many years, researchers have been developing techniques for copyright protection. This paper presents a novel approach for copyright protection of...     

An efficient hybrid DWT-fuzzy filter in DCT domain based illumination normalization for face recognition

Multimedia Tools and Applications - This paper presents an efficient hybrid DWT-DCT based illumination normalization technique for face recognition. In a face image, illumination usually changes...     

Steady state conduction through 2D irregular bodies by smoothed particle hydrodynamics

This paper uses a Lagrangian formulation namely smoothed particle hydrodynamics (SPH) technique for the prediction of conduction heat transfer in irregular geometries. Suitable schemes for the placement of particles inside irregular computational domain have been described. Organization and locations for virtual particles are also discussed for both Dirichlet and Neumann boundary conditions. Three different problems having typical geometries that pose numerical complications in grid based technique, are tackled by SPH efficiently. Conduction shape factor (CSF) for all the problems calculated through SPH shows a good agreement with published results or analytical solutions. Further, the temperature profiles computed by SPH depict close matches with those obtained through numerical software Fluent. The present exercise opens up the possibility of using SPH in varied geometries using different schemes of particle positioning and their judicial combinations.     

Tunneling properties of electromagnetic wave in slab su-perconducting material

When the electromagnetic wave propagates through a slab superconducting material in microwave ranges,tunneling properties of the electromagnetic wave at critical temperature are investigated theoretically.The transmittance and the reflectance of the slab superconducting material vary with the thickness of material as well as the refractive index of substrates.The high transmittance is found for thin superconductor at low wavelength region.However,optical properties are strongly dependent upon temperature and incidence wavelength.The electromagnetic wave is totally transmitted without loss for incidence wavelength(l = 5000 nm) due to the zero refractive index and infinite penetration depth of the superconductor at the critical temperature.     

Modification of narrow‐spectrum peptidomimetic polyurethanes with fatty acid chains confers broad‐spectrum antibacterial activity

Each year, thousands of patients die from antimicrobial‐resistant bacterial infections that fail to respond to conventional antibiotic treatment. Antimicrobial polymers are a promising new method of combating antibiotic‐resistant bacterial infections. We have previously reported the synthesis of a series of narrow‐spectrum peptidomimetic antimicrobial polyurethanes that are effective against Gram‐negative bacteria, such as Escherichia coli; however, these polymers are not effective against Gram‐positive bacteria, such as Staphylococcus aureus. With the aim of understanding the correlation between chemical structure and antibacterial activity, we have subsequently developed three structural variants of these antimicrobial polyurethanes using post‐polymerization modification with decanoic acid and oleic acid. Our results show that such modifications converted the narrow‐spectrum antibacterial activity of these polymers into broad‐spectrum activity against Gram‐positive species such as S. aureus, however, also increasing their toxicity to mammalian cells. Mechanistic studies of bacterial membrane disruption illustrate the differences in antibacterial action between the various polymers. The results demonstrate the challenge of balancing antimicrobial activity and mammalian cell compatibility in the design of antimicrobial polymer compositions. © 2019 Society of Chemical Industry     

A curvelet-based multi-sensor image denoising for KLT-based image fusion

Multimedia Tools and Applications - The transform-based multi-sensor image denoising methods are inefficient in restoring fine details and texture information of noisy images. The fixed and...     

Microstructural analysis of fusion and heat affected zones in electron beam welded ALLVAC 718PLUS™ superalloy

The fusion zone and heat affected zone (HAZ) microstructures of electron beam welded superalloy 718PLUS™ (718 Plus) that has been newly developed by ATI ALLVAC were examined. The microsegregation pattern during solidification of the fusion zone indicated that while Fe, Co, W, and Cr segregated to the core of the gamma dendrites, Nb, Ti, and Al were extensively rejected into the interdendritic liquid. Electron diffraction and X-ray microanalysis using transmission electron microscopy (TEM) of the fusion zone showed that the major secondary phases that formed from the interdendritic liquid were gamma/MC type carbide eutectic and gamma/Laves eutectic constituents. HAZ microstructure showed partially melted zone immediately adjacent to the fusion zone and intergranular microfissuring associated with resolidified products which suggested that HAZ cracking in this alloy occurred by liquation cracking. Microstructural examination of the HAZ using analytical scanning electron microscope showed resolidified gamma/Laves eutectic on the cracked and backfilled grain boundaries. Fine resolidified MC type carbide particles were also observed in the HAZ. Causes of grain boundary liquation were identified and the solidification of intergranular liquid in the HAZ was discussed.     

Cost efficiency benchmarking of urban water supply utilities: The case of an Indian state

In most developing countries like India, benchmarking of water supply utilities is rarely carried out as these services are not run on professional lines to ensure profitability, even as social goals of making provision for all, including the poor, take priority over profitability. When performances of these services are not measured, efforts to improve these services remain directionless and arbitrary. Urban water supplies in India, therefore, suffer a self‐inflicted fate, wherein city municipalities remain mired in mundane issues, leading to large dissatisfaction and inefficiencies. This paper attempts to evolve a framework for evaluating cost efficiencies of water supply services and applies stochastic frontier analysis to 18 urban centres in India through six models. The results indicate large relative inefficiencies and a scope of savings of 24.5% of average current operating and maintenance costs even with existing levels of resource inputs. The results are discussed from a regulatory and policy‐making perspective.