An analytical index for evaluating manufacturing cost and performance of low-pressure hollow fibre membrane systems

Water and waste-water treatment through the use of the membrane filtration technology is one of the processes utilized currently to meet the growing demand for water. While new technologies can harness water from various non-traditional sources such as oceans, there remains the possibility of making drinking water more expensive through the use of costly water treatment equipment. To prevent this and ensuing catastrophes in the world, the water industry needs a strategy that keeps the price of water and price of products aiding the treatment of water controlled in to the future.     

Viscous Potential Flow Analysis of Kelvin–Helmholtz Instability of a Cylindrical Flow with Heat and Mass Transfer

A linear analysis of Kelvin–Helmholtz instability of a cylindrical interface has been carried out when there is heat and mass transfer across the interface, using viscous potential flow theory. Both fluids are considered as incompressible, viscous, and thermally conducting with different kinematic viscosities. Both axisymmetric as well as asymmetric disturbances are considered. Stability criterion is given by a critical value of relative velocity and stability is discussed theoretically as well as numerically. Various graphs with respect to physical parameters such as wave number, viscosity ratio, heat transfer coefficients, Reynolds number, etc., have been drawn and the effect of various parameters have been described. A comparison with the linear stability analysis of inviscid fluids (Lee [10]) has been made and it is observed that viscosity has a stabilizing effect on the stability of the system. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 43(6): 489–503, 2014; Published online 3 October 2013 in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21092     

POSS-based luminescent hybrid material for enhanced photo-emitting properties

In this present work, we have developed a novel POSS type monomer ligand “2,6-pyridinediamine-bis-(propanylheptaisobutyl POSS)” (PDC-POSS) and utilized in the preparation of potential luminescent hybrid complex Eu-PDC-POSS with an inner transition metal ion Eu³⁺. The solubility and photo-emitting properties of new Eu-PDC-POSS hybrid material were studied. The precursor PDC-POSS was synthesized by treating (3-aminopropyl)heptaisobutyl POSS with PDC (2,6-pyridinedicarboxylic acid chloride), and then coordinated with Eu³⁺ using europium nitrate to afford Eu-PDC-POSS hybrid material. The europium-doped hybrid material was characterized using fourier transform infrared spectroscopy, and scanning electron microscopy along with energy dispersive X-ray analysis. The photo emitting properties were studied using a fluorescence spectrophotometer in which, the results showed enhancement in red emission peak at 618 nm for Eu-PDC-POSS, when compared to that of a known solgel-based material Eu-PDC-solgel.     

Effect of composition on steady state and transient photoconductivity in isocoordinated In<Subscript>x</Subscript>Sb<Subscript>30−x</Subscript>Se<Subscript>70</Subscript> (0 ≤ x ≤ 25) chalcogenide films

The study of steady state and transient photocurrent measurement provide important information about carrier generation and recombination phenomena in various semiconducting systems for photo-sensor device applications. In the present work, the composition dependent analysis of photocurrents was studied for thermally evaporated Se-rich In_xSb_30?xSe₇₀ films of average thickness 800 nm. The indirect optical gap has been calculated from the transmission and reflection data and the variation of molecular units was studied from the Raman spectroscopy. The initial rise of photocurrent sharply to approach a steady state value during illumination and fast decay to a constant persistent current after stopping the illumination has been observed. The intensity dependence of photocurrent obeys the power law I_Ph?=?F^γ, where the value of exponent tells about the recombination process. The decay of photocurrent has been fitted with stretched exponential function for different compositions and at different light intensities. These results are important for the development of low cost photo absorbers for solar cell applications and visible region responsive photo sensor devices.     

Design of a cancelable biometric template protection scheme for fingerprints based on cryptographic hash functions

Multimedia Tools and Applications - Enforcing security and privacy guarantees for biometric users via protecting their unique and personalized attributes is an important area of research. There are...     

Metol as Corrosion Inhibitor for zinc

The inhibition behavior of metol (N-methyl-p-aminophenol sulphate) on zinc in different corrosive solutions at room temperature was investigated by various techniques such as weight loss, polarization and linear polarization methods. The percentage inhibition efficiencies were evaluated at different concentrations of the inhibitors. The corrosion rate, inhibition efficiency and surface coverage were dependent on metol concentration. The electrochemical data indicated a basic modification of zinc surface resulting in a decrease in the corrosion rate. Corrosion inhibition was explained by considering an interaction between metal surface and the inhibitor. SEM images and FT-IR profiles confirmed the formation of passive film on the metal surface.     

Poly(ethylene glycol) grafted polystyrene dendrimer resins: Novel class of supports for solid phase peptide synthesis

Poly(propyleneglycol)dimethacrylate cross-linked support using monomers Styrene and 4-chloromethyl styrene (PS-PPGDMA-VBC resin) was prepared by suspension polymerization method. Dendritic templates were synthesized from Schiff base and trimesic acid molecules and assembled independently on PS-PPGDMA-VBC support to the second generation. N,N-bischloro ethyl amine dendrimer was generated from Schiff base units and introduced to the chloromethyl groups uniquely through secondary amine. It was followed by acidolytic cleavage, diazotization and thionyl chloride reactions leading to first generation dendrimer. O-benzyl ether dendrimer was created using 1,3,5-tris(hydroxyl methyl)benzene unit which was produced by the LiAlH₄ reduction of carbonyl groups of trimesic acid molecule. The hydroxyl methyl groups formed were converted to chloro methyl groups by adding thionyl chloride that leads to first generation dendrimer. Similar synthetic routes were followed to produce second generation dendrimers too. Poly(ethylene glycol), M_n ≈ 1500) has been grafted to chlorine termini of both dendrimers and used to check various physical and chemical properties of different peptide synthetic conditions. Reactions were qualitatively analyzed by FTIR, ¹³C NMR, SEM and quantitatively analyzed by UV measurements and CHN analysis. Classically difficult ACP sequence was synthesized on both PEGylated dendrimer supports and compared to Tenta Gel. Biologically significant disulfide bonded endothelin class of peptides were also synthesized using novel supports using various literature reported methods.     

A hybrid Taguchi-artificial neural network approach to predict surface roughness during electric discharge machining of titanium alloys

In the present study, electric discharge machining process was used for machining of titanium alloys. Eight process parameters were varied during the process. Experimental results showed that current and pulse-on-time significantly affected the performance characteristics. Artificial neural network coupled with Taguchi approach was applied for optimization and prediction of surface roughness. The experimental results and the predicted results showed good agreement. SEM was used to investigate the surface integrity. Analysis for migration of different chemical elements and formation of compounds on the surface was performed using EDS and XRD pattern. The results showed that high discharge energy caused surface defects such as cracks, craters, thick recast layer, micro pores, pin holes, residual stresses and debris. Also, migration of chemical elements both from electrode and dielectric media were observed during EDS analysis. Presence of carbon was seen on the machined surface. XRD results showed formation of titanium carbide compound which precipitated on the machined surface.