Concept and validation of a fully automated photocatalytic test setup

Photocatalytic activity can be studied by several methods, each with its own strengths and weaknesses. To study photocatalytic activity in an easy, user-friendly, and realistic way, a completely new setup has been built. The setup is modularly constructed around Fourier transform infrared spectroscopy (FTIR) spectroscopy at the heart of it, resulting in great versatility. Complementary software has been written for automatic control of the setup and for processing the generated data. Two pollutants, oil and n-octane, are tested to validate the performance of the setup. These validation experiments confirm the usefulness and added value of the setup in general and of the FTIR detection methodology as well. It becomes clear that a system of online measurements with good repeatability, accuracy, and user-friendliness has been created.     

Incorporation and use of modified nucleotides in aqueous DNA computing

The concept of aqueous computing involves the use of large numbers of initially identical molecules to serve as memory registers in a fluid environment. Here, we test a new approach to aqueous computing where modified nucleotides are used to “write” on double-stranded DNA molecules to establish the logical values of true or false for a set of clauses. We introduce an implementation scenario where binding proteins specific to each modification can be used to selectively isolate DNA fragments with these modified nucleotides. In addition, we present initial results showing successful incorporation and detection of modifications. We have successfully labeled DNA fragments with four modifications, specifically Alexa Fluor-488, BODIPY-FL, biotin, and digoxigenin using polymerase chain reaction. The first two produce fluorescent molecules that can be distinguished by their color. We have confirmed that binding proteins or antibodies to these four modifications are specific and do not detect the other modifications. We have also successfully separated the DNAs labeled with Alexa Fluor and biotin using binding proteins. We present attempts at rebinding these modified molecules to a second binding protein; the equivalent of applying more than one clause to a set of values. We have found some challenges with this approach that likely can be resolved with further work. As there are millions of molecules with corresponding binding proteins, this approach has the potential to yield unlimited computing power as compared with other aqueous computing methods.     

Deformation Characteristics and Recrystallization Response of a 9310 Steel Alloy

The flow behavior and recrystallization response of a 9310 steel alloy deformed in the ferrite temperature range were studied in this work. Samples were compressed under various conditions of strain (0.6, 0.8 and multi-axial), strain rate (10^?4 seconds^?1 to 10^?1 seconds^?1) and temperature [811 K to 1033 K (538 °C to 760 °C)] using a Gleeble thermo-mechanical simulator. Deformation was characterized by both qualitative and quantitative means, using standard microscopy, electron backscatter diffraction (EBSD) analysis and flow stress modeling. The results indicate that deformation is primarily accommodated through dynamic recovery in sub-grain formation. EBSD analysis shows a continuous increase in sub-grain boundary misorientation with increasing strain, ultimately producing recrystallized grains from the sub-grains at high strains. This suggests that a sub-grain rotation recrystallization mechanism predominates in this temperature range. Analyses of the results reveal a decreasing mean dynamically recrystallized grain size with increasing Zener-Hollomon parameter, and an increasing recrystallized fraction with increasing strain.     

Sensitivity analysis of the split-complex valued multilayer perceptron due to the errors of the i.i.d. inputs and weights.

In this paper, we analyze the sensitivity of a split-complex multilayer perceptron (split-CMLP) due to the errors of the inputs and the connection weights between neurons. For simplicity, all the inputs and weights studied here are independent and identically distributed (i.i.d.). To develop an algorithm to estimate the sensitivity of the entire split-CMLP, we compute statistically the sensitivity by using the central limit theorem (CLT). The results show that the sensitivity is affected by the number of the layers and the number of the neurons adopted in each layer. We derive a theoretical estimation of the sensitivity. Several numerical results of the sensitivity for the split-CMLP are presented, and they match the theoretical ones. The agreement between the theoretical results and experimental results verifies the feasibility of the proposed algorithm. Thus, we not only analyze the sensitivity of the split-CMLP due to the errors of the i.i.d. inputs and weights, but also develop an efficient algorithm to estimate the sensitivity.     

Effects of partial substitutions of cerium and aluminum on the hydrogenation properties of La(0.65−x)CexCa1.03Mg1.32Ni(9−y)Aly alloy

Hydrogen in metal hydrides could be one of the promising energy storage mediums to address the intermittent nature of renewable energy. To convert the hydrogen energy to electricity, the storage system has to be coupled with a fuel cells system. Hence, it is important to design a hydrogen storage system that meets the operating requirements for a fuel cell system. In this work, the effects of partial substitution of both cerium and aluminum on the hydrogenation properties of La_(0.65−x)Ce_xCa_1.03Mg_1.32Ni_(9−y)Al_y alloys were investigated simultaneously using factorial design. Both Ce and Al additions greatly improved the reversibility of hydrogen storage capacity. However, the maximum hydrogen storage capacity and absorption kinetics can be reduced by the additions. As Ce and Al gave opposite effects on the absorption and desorption plateaus, they could be used to tune the properties of the alloys to the desired operating conditions for fuel cell applications.     

Nonlinear associations between blood lead in children, age of child, and quantity of soil lead in metropolitan New Orleans

Previous studies identified a curvilinear association between aggregated blood lead (BL) and soil lead (SL) data in New Orleans census tracts. In this study we investigate the relationships between SL (mg/kg), age of child, and BL (μg/dL) of 55,551 children in 280 census tracts in metropolitan New Orleans, 2000 to 2005. Analyses include random effects regression models predicting BL levels of children (μg/dL) and random effects logistic regression models predicting the odds of BL in children exceeding 15, 10, 7, 5, and 3 μg/dL as a function of age and SL exposure. Economic benefits of SL reduction scenarios are estimated. A unit raise in median SL^0.5 significantly increases the BL level in children (b = 0.214 p = < 0.01), and a unit change in Age^0.5 significantly increases child BL (b = 0.401, p = < 0.01). A unit change in Age^0.5 increases the odds of a child BL exceeding 10 μg/dL by a multiplicative factor of 1.23 (95% CI 1.21 to 1.25), and a unit (mg/kg) addition of SL increases the odds of child BL > 10 μg/dL by a factor of 1.13 (95% CI 1.12 to 1.14). Extrapolating from regression results, we find that a shift in SL regulatory standard from 400 to 100 mg/kg provides each child with an economic benefit ranging from $4710 to $12,624 ($US 2000). Children's BL is a curvilinear function of both age and level of exposure to neighborhood SL. Therefore, a change in SL regulatory standard from 400 to 100 mg/kg provides children with substantial economic benefit.