Coating of finished flax particle boards with insoluble gelatin

Coating of finished flax particle boards with gelatin only, did not improve the resistance of boards to hot water. Coating with gelatin rendered insoluble, however, using hexamine and high temperature produced an insoluble gelatin film on the flax particles, which improved water resistance of the coated boards. Particle boards coated with 5% gelatin and a high concentration of hexamine (10%), improved water resistance to about 50% higher than that of uncoated samples. Higher amounts of gelatin (7.5 and 10%) gave a smaller improvement. The changes in thickness and density of the coated samples were also investigated.     

Enhanced growth rate and lipid production of freshwater microalgae by adopting two‐stage cultivation system under diverse light and nutrients conditions

This study aims to investigate the growth behaviour and lipid production of Chlorella vulgaris (a microalga) by manipulating the effect of light and nutrients. In our presumptive two‐staged growth model, C. vulgaris was first grown under low levels of light and nutrients in stage 1 and then in stage 2 under several combinations of light and nutrients, Nt?/Lt? minimum nutrients and minimum light as control; Nt+/Lt+ maximum light and maximum nutrients; Nt+/Lt? maximum nutrients and minimum light, and Nt?/Lt+ minimum nutrients and maximum light. Doubling time reduced from 46.8 ± 02 hours in control (Nt?/Lt?) to 36.1 ± 04 in Nt?/Lt+ and 37.7 ± 0.9 in Nt+/Lt? and further down to 25.2 ± 03 h in Nt+/Lt+. The highest lipid contents were found in Nt?/Lt+ (9.5 ± 0.14%) followed by Nt+/Lt+ (8.6 ± 0.2%), Nt+/Lt? (6.4 ± 0.12%) and Nt?/Lt? (6.1 ± 0.22%), respectively. The maximum biomass (909 mg/L) was found in Nt+/Lt+ likely suggesting that limited growth in control was attributed to the limitation of nutrients and light. Incremental addition of light and nutrients is suggested for enhanced growth rate, biomass and lipid production.     

Multi-criteria evaluation of hydrogen and natural gas fuelled power plant technologies

This paper evaluates nine types of electrical energy generation options with regard to seven criteria. The options use natural gas or hydrogen as a fuel. The Analytic Hierarchy Process was used to perform the evaluation, which allows decision-making when single or multiple criteria are considered.The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine.The criteria used for the evaluation are CO₂ emissions, NO_X emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost.A total of 19 scenarios were studied. In 15 of these scenarios, the hydrogen turbine ranked first and proved to be the most preferred electricity production technology. However since the hydrogen combustion turbine is still under research, the most preferred power generation technology which is available nowadays proved to be the natural gas combined cycle which ranked first in five scenarios and second in eight. The last in ranking electricity production technology proved to be the natural gas fuelled phosphoric acid fuel cell, which ranked in the last position in 13 scenarios.     

Hydrogen production by thermo-catalytic conversion of methane over lanthanum strontium cobalt ferrite (LSCF) and αAl2O3 supported Ni catalysts

This study investigates hydrogen production by thermo-catalytic steam methane reforming over lanthanum strontium cobalt ferrite supported Nickel (Ni/LSCF) and commercial Ni/$\alpha$Al₂O₃ catalysts. The Ni/LSCF catalyst was synthesized using wet impregnation method and characterized by XRD, TEM, SEM, EDX, N₂-physisorption analysis, and H₂-TPR. The characterization analyses show that Ni/LSCF and Ni/$\alpha$Al₂O₃ possess the required physicochemical properties to catalyze the steam methane reforming reaction. The activity of the Ni/LSCF catalyst in steam methane reforming at 750 °C, 800 °C, and 850 °C resulted in CH₄ conversions of 73.46%, 78.67%, and 87.56%, respectively. In addition, hydrogen (H₂) yields of 64.34%, 72.57%, and 82.56% were obtained from the steam methane reforming at 750 °C, 800 °C, and 850 °C, respectively over the Ni/LSCF catalyst. The Ni/LSCF catalyst was found to have higher activities in term of CH₄ conversion and H₂ yield compare to the commercial Ni/$\alpha$Al₂O₃. However, the stability test conducted at 480 min time on stream (TOS) revealed that the commercial Ni-αAl₂O₃ was more stable in the steam methane reforming than the Ni/LSCF catalyst. The characterization of the used catalysts by TEM, XRD and TGA shows evidence of carbon deposition mostly on the used Ni/LSCF catalyst.     

Heat inactivation of Listeria monocytogenes and Salmonella enterica serovar Typhi in a typical bologna matrix during an industrial cooking-cooling cycle

The heat resistance of Salmonella enterica serovar Typhi PF-724 and Listeria monocytogenes 2812 was determined in a commercial bologna batter. The heat inactivation of the two bacterial species was also studied in a semiautomatic pilot smokehouse under cooking conditions that reproduced an industrial bologna process. S. enterica serovar Typhi PF-724 was less heat resistant than L. monocytogenes 2812. The D-values (times required to reduce the population by 1 logarithmic cycle) for S. enterica serovar Typhi PF-724 ranged from 10.11 to 0.04 min for temperatures of 50 to 70 degrees C, while for L. monocytogenes 2812, the D-values were 2.5-, 4.9-, 3.8-, 3.3-, and 2-fold higher at 50, 55, 60, 65, and 70 degrees C, respectively, than for S. enterica serovar Typhi PF-724. However, the z-value (temperature required to reduce log D by 1 logarithmic cycle) for S. enterica serovar Typhi PF-724 (5.72 degrees C) was not significantly different from the z-value for L. monocytogenes 2812 (7.04 degrees C), indicating that a given increase in temperature would have a similar effect on the decimal reduction time for both bacterial species in that meat emulsion. Our data on experimentally inoculated batter also showed that processing bologna at a cooking-cooling cycle commonly used in the industry resulted in a minimum 5-log reduction for both S. enterica serovar Typhi PF-724 and L. monocytogenes 2812.     

Radial mask for imaging systems that exhibit high resolution and extended depths of field

A novel algorithm for the design of an imaging system that exhibits high resolution as well as extended depth of field is presented. This novel approach searches for an optimal pupil mask that minimizes the value of the mean-square error when performed over the intensity rather than in the field distribution of the acquired image. The captured images in such system do not require any postprocessing, and thus utilization of such a system is simplified. Simulations as well as experimental results are provided.     

Performance of imaging systems analyzed with two-dimensional target

We have recently shown [Appl. Opt.51, 2739 (2012)] that performance analysis of optical imaging systems based on results obtained with classic one-dimensional (1D) resolution targets (such as the U.S. Air Force resolution target) are significantly different than those obtained with a newly proposed two-dimensional (2D) target. We hereby provide experimental evidence and show how the new 2D template can be used to correctly characterize optical imaging systems in terms of resolution and contrast. In particular, we apply the consequences of these observations to the optimal design of some 2D barcode structures.