Membrane concentration potentials across heavy metal soap membranes

The alumina mixed copper soap pellets of different fatty acids (C₆−C₁₆) have been prepared. The pellets are used as membranes of electropositive character. The concentration potential studies have been carried out with potassium chloride solutions. Transport number of counterions and selective ionic permeability through these membranes have been calculated. The values of both these parameters increase with increase in the number of C-atoms of the hydrocarbon chain of copper soaps. This seems to be due to lowering in solubility and increase in crosslinking in the membrane material.     

Preparation of cupric palmitate membrane,its characterization and evaluation of thermodynamically effective fixed charge density

Membrane potentials have been measured across, parchment-supported cupric palmitate membrane separating various 1∶1 electrolytes at concentrations C₁ and C₂ such that C₂=10 C₁. Membrane potential data have been used to calculate transference number of ions, permselectivity and also to derive the thermodynamically effective fixed charge density which is an important characteristic governing the membrane phenomena, by utilizing the generally accepted and most widely used theory of Teorell-Meyer and Sievers as well as the recent theories for membrane potential of Kobatake et al. and Nagasawa et al. based on the principles of nonequilibrium thermodynamics. The values of charge densities derived from different theories were almost the same, confirming thereby the validity of the recently developed theories of membrane potential.     

Effect of enzyme inhibition on the performance of packed-bed biological reactor - a theoretical study

The performance characteristic of a packed bed reactor has been analyzed by considering diffusional resistance of the biofilm. Model equations were solved by the method of orthogonal collocation for various classical enzyme inhibition kinetics, including partially non-competitive, partially competitive, partially uncompetitive, partially mixed and fully mixed. For all considered modes of inhibition, an increase in the inlet substrate concentration decreases the steady state conversion in the reactor. However, an increase in the Peclet number has been found to improve the conversion. The effects of various other process variables of physical importance were also investigated parametrically.     

SOLUBILITY STUDIES OF PARAFFIN WAXES IN SELECTED PETROLEUM FRACTIONS AND TOLUENE

Solubility studies of paraffin waxes with melting point range of 43^°C to 57^°C in two undefined petroleum fractions and Toluene have been carried out. An Attempt was made to develop a correlation for predicting the solubility of the waxes in these solvents. The one parameter ideal solubility law expression has been successfully used to represent the experimental data.     

GPU-accelerated registration of hyperspectral images using KAZE features

The Journal of Supercomputing - Image registration is a common task in remote sensing, consisting in aligning different images of the same scene. In the particular case of hyperspectral images, the...     

Extended attribute profiles on GPU applied to hyperspectral image classification

The Journal of Supercomputing - Extended profiles are an important technique for modelling the spatial information of hyperspectral images at different levels of detail. They are used extensively...     

Studies with inorganic precipitate membrane: evolution of thermodynamically effective fixed charge density and test of the most recently developed theory of membrane potential based on the principles of non-equilibrium thermodynamics

Electrical potentials developed across nickel, manganese chromate and cupric iodide membranes using various 1:1 electrolytes are reported. Thermodynamically effective fixed charge density, which is an important parameter governing the membrane phenomena, has been evaluated by the recently developed theory of Nagasawa et al. Most recently developed theories of Toyoshima and Nozaki based on the principles of the irreversible thermodynamics has been examined to predict the bi-ionic potentials developed across the membranes. Theoretical predictions were borne out quite satisfactorily by our experimental results.     

An Effective Approach for High‐Efficiency Photoelectrochemical Solar Cells by Using Bifunctional DNA Molecules Modified Photoanode

This paper firstly reports the effect of deoxyribonucleic acid (DNA) molecules extracted from chickpea and wheat plants on the injection/recombination of photogenerated electrons and sensitizing ability of dye‐sensitized solar cells (DSSCs). These high‐yield DNA molecules are applied as both linker bridging unit as well as thin tunneling barrier (TTB) at titanium dioxide (TiO₂ )/dye interface, to build up high‐efficient DSSCs. With its favorable energy levels, effective linker bridging role, and double helix structure, bifunctional DNA modifier shows an efficient electron injection, suppressed charge recombination, longer electron lifetime, and higher light harvesting efficiency, which leads to higher photovoltaic performance. In particular, a photoconversion efficiency (PCE) of 9.23% is achieved by the binary chickpea and wheat DNA‐modified TiO₂ (CW@TiO₂) photoanode. Furthermore, time‐resolved fluorescence spectroscopy measurements confirm a better electron transfer kinetics for DNA‐modified TiO₂ photoanodes, implying a higher electron transfer rate (k_ET). This work highlights a great contribution for the photoanodes that are linked with DNA molecule, which act as both bridging unit and TTB to control the charge recombination and injection dynamics, and hence, boost the photovoltaic performance in the DSSCs.     

Modelling of simultaneous methanogenesis and denitrification in an upflow packed-bed biofilm reactor

The performance of an upflow packed-bed biofilm reactor was investigated by considering simultaneous methanogenesis and denitrification reactions under step and sinusoidal variations of feed concentration and temperature. For simultaneous step inputs of 20 mg dm⁻³ of NO₃⁻—N and 60 mg dm⁻³ of methanol, the proposed model shows that major conversion of both the substrates takes place in the first half of the reactor. However, when the inlet concentration of methanol is subjected to sinusoidal variation, while that of NO₃⁻—N is maintained stepwise, the exit concentration of both methanol and NO₃⁻—N follow a sinusoidal response. On the other hand, when the inputs are reversed (methanol stepwise and NO₃⁻—N sinusoidal), the response exhibits similar behaviour. For sinusoidal variation of feed temperature the exit concentration profiles of both substrates also follow a sinusoidal pattern. For methanol, the mean steady state conversion under sinusoidal variation is higher than the corresponding steady state concentration when feed temperature is constant at 30°C. The model predictions are in good agreement with the experimental data available in the literature. ©1997 SCI