Expanded bed adsorption for purification of alcohol dehydrogenase using a dye-iminodiacetic acid matrix

Expanded bed adsorption (EBA) was successfully applied for the purification of alcohol dehydrogenase (ADH) from unclarified bakers' yeast homogenate using a new dye-iminodiacetic acid (IDA) matrix carrying immobilized metal ions. The existence of cells and cell debris do not have a significant effect on the adsorption of ADH on the matrix. The presence of imidazole in adsorption buffer was found to be an important factor in reducing the level of the adsorbed contaminant proteins. The optimal imidazole concentration was 5 mM. The dynamic binding capacity of the dye-IDA matrix in EBA was found to be 569 U/ml matrix. A chromatography of one-step elution with imidazole was developed, in which ADH was successfully adsorbed in the presence of 5 mM imidazole; subsequently, the column was washed with 5 mM imidazole containing 1 M NaCl and eluted with 150 mM imidazole containing 1.5 M NaCl. The purification factor and ADH recovery were 8.8 and 93.5%, respectively.     

Experimental Investigation of Gas/Matte/Spinel Equilibria in the Cu-Fe-O-S System at 1473 K (1200 °C) and <Emphasis Type="Italic">P</Emphasis>(SO<Subscript>2</Subscript>) = 0.25 atm

The Cu-Fe-O-S system is the key system for the characterisation of the phase chemistry in high-temperature copper making processes. An experimental study was undertaken to investigate the gas/matte/spinel equilibria in the Cu-Fe-O-S system at 1473 K (1200 °C), P(SO₂) = 0.25 atm, and a range of oxygen partial pressures. The experimental methodology involved high temperature equilibration using a primary phase substrate technique in controlled gas atmospheres (CO/CO₂/SO₂/Ar), rapid quenching of the equilibrated phases, followed by direct measurement of phase compositions using electron probe x-ray microanalysis. Particular attention was given to the analysis of reactions during equilibration and confirmation of the achievement of equilibrium in the present study. The new data provide important information for understanding of the gas/matte/spinel interactions at high temperature and provide an essential foundation for the development of the multicomponent thermodynamic database for copper-containing systems.     

A new species of Platygaster (Hymenoptera: Platygastridae) reared from Orseolia javanica (Diptera: Cecidomyiidae) on cogon grass,Imperata cylindrica (Poaceae)

Platygaster orseoliae sp. n. is described from West Java, Indonesia, reared from Orseolia javanica on cogon grass, Imperata cylindrica, with information on the parasitism rate of P. orseoliae and of other parasitoid wasp species reared from O. javanica in connection with the present study. The affinities of P. orseoliae are discussed, and the rearing method is briefly described.     

Feasibility-Guided Constraint-Handling Techniques for Engineering Optimization Problems

The particle swarm optimization (PSO) algorithm is an established nature-inspired population-based meta-heuristic that replicates the synchronizing movements of birds and fish. PSO is essentially an unconstrained algorithm and requires constraint handling techniques (CHTs) to solve constrained optimization problems (COPs). For this purpose, we integrate two CHTs, the superiority of feasibility (SF) and the violation constraint-handling (VCH), with a PSO. These CHTs distinguish feasible solutions from infeasible ones. Moreover, in SF, the selection of infeasible solutions is based on their degree of constraint violations, whereas in VCH, the number of constraint violations by an infeasible solution is of more importance. Therefore, a PSO is adapted for constrained optimization, yielding two constrained variants, denoted SF-PSO and VCH-PSO. Both SF-PSO and VCH-PSO are evaluated with respect to five engineering problems: the Himmelblau’s nonlinear optimization, the welded beam design, the spring design, the pressure vessel design, and the three-bar truss design. The simulation results show that both algorithms are consistent in terms of their solutions to these problems, including their different available versions. Comparison of the SF-PSO and the VCH-PSO with other existing algorithms on the tested problems shows that the proposed algorithms have lower computational cost in terms of the number of function evaluations used. We also report our disagreement with some unjust comparisons made by other researchers regarding the tested problems and their different variants.     

A Review on Composite Papers of Graphene Oxide,Carbon Nanotube,Polymer/GO,and Polymer/CNT: Processing Strategies,Properties, and Relevance

In this review, particular importance is given to the fabrication and properties of carbon nanotube and graphene oxide-based paper-like materials (buckypapers). Different strategies for the reduction and functionalization of graphene oxide were also discussed. The chemistry of buckypapers is conversed with special emphasis on structure and essential characteristics of buckypaper. Various techniques for buckypaper processing have been critically reviewed including significance of each method. Moreover, importance of polymer/graphene oxide and polymer/carbon nanotube composite papers has been highlighted. Due to outstanding physical, thermal, and electrical properties, polymer-based buckypapers are potentially important as nanofilters, fuel cell components, and miniaturization of electrical connections.     

Dielectric,ferroelectric and piezoelectric properties of (1-x)(Bi0.5Na0.5)0.935Ba0.065Ti -x(LiSbO3) solid solutions

Compositions in the solid solution series (1-x)(Bi_0.5Na_0.5)_0.935Ba_0.065Ti–x(LiSbO₃), (BNBT-LS) (x = 0, 0.01, 0.02, 0.03, 0.04) have been fabricated via solid state reaction route. Room temperature x-ray diffraction traces of all samples were found to reveal coexistence of the two structures; rhombohedral and tetragonal. The micrographs recorded from the Field Emission Scanning Electron Microscope, provided an overall dense and single phase microstructure for the systems. The dielectric anomalies corresponding to the maximum relative dielectric constant, ε_r, persistently broadened and shifted to low temperatures as a function of increase in LiSbO₃ (LS) content. The ferroelectric $\mathrm{P}?\mathrm{E}$ loops became steadily narrow with similar LS modification showing a continual decline in remnant polarization $({\mathrm{P}}_{\mathrm{r}})$ and coercive field $({\mathrm{E}}_{\mathrm{c}})$. These phenomena clearly indicated the onset of a growing relaxor-like behavior. The maximum normalized unipolar strain $\left({\mathrm{S}}_{\max }/{\mathrm{E}}_{\max }={\mathrm{d}}_{33}^{*}=400\mathrm{pm}/\mathrm{V}\right)$ under the field 50 kV/cm was recorded for the system with x = 0.02.     

Application of Response Surface Methodology for the Optimization of β-Carotene-Loaded Nanostructured Lipid Carrier from Mixtures of Palm Stearin and Palm Olein

The main purpose of this study was to optimize a β-carotene-loaded nanostructured lipid carrier (βC-NLC) using the lipid matrix of palm stearin and palm olein and Tween 80 as a surfactant. The NLC was prepared by using the high shear homogenization method. Box–Behnken Design (BBD) response surface methodology (RSM) was applied to optimize the process and formulation. A three-factor experimental model was used to optimize the combination of palm stearin ratio (A, %w/w), lipid:surfactant ratio (B, %w/w), and (lipid+surfactant):water ratio (C, %w/w). The formulations were evaluated for their responses on particle size (Y1), polydispersity index (Y2), zeta potential (Y3), and encapsulation efficiency (Y4). Subsequently, Fourier-transform infrared spectroscopy (FTIR), thermal (DT-TGA), x-ray diffraction (XRD), transmission electron microscopy (TEM), and in vitro release (Franz diffusion cell) analyses were utilized to observe the resulting optimum formulation. The optimum formulation was obtained at a combination of A (5.5:4.5), B (1:4.9), and C (24:76) %w/w. This resulted in βC-NLC having a particle size of 166 nm, polydispersity index of 0.35, zeta potential of −26.9 mV, and an encapsulation efficiency of 91.2%. No strong interaction between different NLC components was observed based on FTIR, DT-TGA, and XRD profiles. Round-shaped NLC particles were observed under TEM. Franz diffusion cell observation resulted in diffusion profile of β-carotene of 110.6 μg cm⁻² with a flux of 1.06 (μg cm⁻² hour⁻¹). This indicates that palm stearin and palm olein can be prospectively developed as βC-NLC.     

Enzymatic glycerolysis–interesterification of palm stearin–olein blend for synthesis structured lipid containing high mono- and diacylglycerol

Food Science and Biotechnology - The objective of this research was to evaluate enzymatic glycerolysis–interesterification to synthesize structured lipids (SLs) containing high...