Comparison Between Granular Starch Hydrolyzing Enzyme and Conventional Enzymes for Ethanol Production from Maize Starch with Different Amylose: Amylopectin Ratios

The effect of enzyme treatments (granular starch hydrolyzing and conventional enzymes) and different amylose: amylopectin ratios of maize starch on ethanol production was evaluated. For starch treatments, amylose: amylopectin ratios were prepared by mixing commercially available Hylon VII (70% amylose and 30% amylopectin) and Amioca (˜100% amylopectin) starches. For maize treatments, waxy, high amylose and regular dent hybrids were used to represent varying amylose: amylopectin ratios. All hydrolyses followed by fermentations were conducted at 15% solids content. Differences were observed in ethanol yields among granular starch hydrolyzing and conventional enzymes. Differences also were observed in ethanol yields between different amylose: amylopectin ratios for pure starch and maize samples. For starch samples, final ethanol concentrations varied from 2.2 to 9.1% (v/v) for fermentation with granular starch hydrolyzing enzyme and from 6.7 to 9.3% (v/v) for conventional enzymes. Higher ethanol concentrations were observed for Amioca starch for both enzymes. For maize samples, final ethanol concentrations were highest for waxy maize for both granular starch hydrolyzing (8.2%, v/v) and conventional (8.2%, v/v) enzymes. Lowest ethanol concentrations were observed for high‐amylose maize samples for granular starch hydrolyzing (6.3%, v/v) and conventional (5.2%, v/v) enzymes.     

Use of adsorption using granular activated carbon (GAC) for the enhancement of removal of chromium from synthetic wastewater by electrocoagulation

The present work deals with removal of hexavalent chromium from synthetic effluents in a batch stirred electrocoagulation cell with iron-aluminium electrode pair coupled with adsorption using granular activated carbon (GAC). Several working parameters such as pH, current density, adsorbent concentration and operating time were studied in an attempt to achieve higher removal capacity. Results obtained with synthetic wastewater revealed that most effective removal capacities of chromium (VI) could be achieved when the initial pH was near 8. The removal of chromium (VI) during electrocoagulation, is due to the combined effect of chemical precipitation, coprecipitation, sweep coagulation and adsorption. In addition, increasing current density in a range of 6.7-26.7mA/cm2 and operating time from 20 to 100min enhanced the treatment rate to reduce metal ion concentration below admissible legal levels. The addition of GAC as adsorbent resulted in remarkable increase in the removal rate of chromium at lower current densities and operating time, than the conventional electrocoagulation process. The method was found to be highly efficient and relatively fast compared to existing conventional techniques.     

Magnetic properties of nano-crystalline Li0.35Cd0.3Fe2.35O4 ferrite prepared by modified citrate precursor method

Single phase nano-crystalline lithium cadmium ferrite Li_0.35Cd_0.3Fe_2.35O₄ is synthesized by a modified citrate gel precursor technique in different pH media. The modified citrate precursor technique reduces the formation of the impurity phase α-Fe₂O₃ in the inverse spinel phase of lithium ferrite. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the average crystallite size. As-prepared sample shows the paramagnetic behaviour of M–H curve measured by vibrating sample magnetometer (VSM). The coercivity (H_c) and magnetization (M) both increase with decrease in temperature from 300 K to 80 K. Temperature dependent magnetic properties below the Curie point are defined by the Bloch's law and Neel relaxation relations. The effect of annealing on magnetic properties at different temperature is studied.     

Conductivity reduction due to emulsification during surfactant enhanced-aquifer remediation. 2. Formation of emulsion in situ

Permeability reduction due to surfactant emulsification can impact the effectiveness of surfactant-enhanced aquifer remediation (SEAR). The objective of this study was to examine the process of in situ emulsification in systems composed of tetrachloroethylene (PCE) and solutions of two nonionic surfactants selected for their ability to enhance solubility. The injection of the surfactant solutions into columns packed with sand-sized silica particles containing residual saturations of PCE resulted in the formation of an emulsion with an average droplet diameter of 0.1-0.2 microm, about an order of magnitude smaller than that of the ex situ formed emulsion. The measurements of hydraulic conductivity showed an initial decrease, followed by a gradual increase, with a final steady-state reduction of about 35% after the injection of 7-8 pore volumes of surfactant solution, of which about 8% could be attributed to the deposition of the emulsion. To describe the observed trends, the modified emulsion transport model from Part 1 was modified to include the processes of the formation of the emulsion and the reduction of the PCE residual. The good comparison between the simulations and the experimental data suggests that the model correctly reflects the multiple processes controlling the hydraulic conductivity of the packed columns during surfactant solution injection.     

On the development of computer bases path planning strategies for Robotic Spray Glazing

The use of off-line programming is an important step in the implementation of effective CAD-CAM integration. This paper first outlines the tasks involved in the CAD-based off-line programming of spray glazing robots. Different interactive path specification methods and glaze spraying strategies are presented.     

MODELING OF TURBULENT, NEUTRALLY BUOYANT DROPLET SUSPENSIONS IN LIQUIDS

The mixing of neutrally buoyant, immiscible droplets in suspension in a turbulent liquid is being studied. In a statistically homogeneous field, it is anticipated that the droplets will affect the turbulent eddies, and that the turbulence will cause the droplets to break-up and coalesce. A cascade model is constructed by extension of the Desnyansky and Novikov equation, accounting for the wavenumber dependence of the fluctuating energy, for the intermittency factor of the turbulence and for the droplet population. In the absence of breakage and coalescence, interactions between eddies and droplets are assumed to be of collision type, so that the exchange of energy and the modifications to the eddy and droplet populations can be described. The resulting equations are solved for a fixed droplet population, showing the effect of droplet size on the turbulent energy spectrum. Continuation of the work is discussed, including droplet breakage and coalescence, as well as the introduction of non-homogeneous distributions.