Electroform replication used for multiple x-ray mirror production

Work done to produce x-ray mirrors via electroform replication is reported. Several advances have been made over previous work. We have produced lower grazing incidence angle (30 min) mirrors, obtained quantitative measurements up to higher energies (6.40 keV), produced about four times as many replicas from one mandrel, and obtained angular resolutions better than other work done with replicated metal mirrors.     

Molybdenum Dioxide in Carbon Nanoreactors as a Catalytic Nanosponge for the Efficient Desulfurization of Liquid Fuels

The principle of a “catalytic nanosponge” that combines the catalysis of organosulfur oxidation and sequestration of the products from reaction mixtures is demonstrated. Group VI metal oxide nanoparticles (CrO_x, MoO_x, WO_x) are embedded within hollow graphitized carbon nanofibers (GNFs), which act as nanoscale reaction vessels for oxidation reactions used in the decontamination of fuel. When immersed in a model liquid alkane fuel contaminated with organosulfur compounds (benzothiophene, dibenzothiophene, dimethyldibenzothiophene), it is found that MoO₂@GNF nanoreactors, comprising 30 nm molybdenum dioxide nanoparticles grown within the channel of GNFs, show superior abilities toward oxidative desulfurization (ODS), affording over 98% sulfur removal at only 5.9 mol% catalyst loading. The role of the carbon nanoreactor in MoO₂@GNF is to enhance the activity and stability of catalytic centers over at least 5 cycles. Surprisingly, the nanotube cavity can selectively absorb and remove the ODS products (sulfoxides and sulfones) from several model fuel systems. This effect is related to an adsorptive desulfurization (ADS) mechanism, which in combination with ODS within the same material, yields a “catalytic nanosponge” MoO₂@GNF. This innovative ODS and ADS synergistic functionality negates the need for a solvent extraction step in fuel desulfurization and produces ultralow sulfur fuel.     

An Integrated Assessment of the Impacts of Hydrogen Economy on Transportation, Energy Use, and Air Emissions

This paper presents an analysis of the potential system-wide energy and air emissions implications of hydrogen fuel cell vehicle (H ₂-FCV) penetration into the U.S. light duty vehicle (LDV) fleet. The analysis uses the U.S. EPA MARKet ALlocation (MARKAL) technology database and model to simultaneously consider competition among alternative technologies and fuels, with a focus on the transportation and the electric sectors. Our modeled reference case suggests that economics alone would not yield H₂-FCV penetration by 2030. A parametric sensitivity analysis shows that H₂-FCV can become economically viable through reductions in H ₂-FCV costs, increases in the costs of competing vehicle technologies, and increases in oil prices. Alternative scenarios leading to H₂-FCV penetration are shown to result in very different patterns of total system energy usage depending on the conditions driving H₂-FCV penetration. Overall, the model suggests that total CO₂ emissions changes are complex, but that CO₂ emission levels tend to decrease slightly with H₂-FCV penetration. While carbon capture and sequestration technologies with H ₂ production and renewable technologies for H₂ production have the potential to achieve greater CO₂ reductions, these technologies are not economically competitive within our modeling time frame without additional drivers     

Portal hypertension changes following selective splenorenal shunt surgery. Evaluation by percutaneous transhepatic portal catheterization, venography, and cinefluorography

A series of ergot alkaloids, together with the DA agonists apomorphine and piribedil, were tested for protective effects against audiogenic seizures in an inbred strain of mice (DBA/2) and for induction of circling behaviour in mice with unilateral destruction of one nigrostriatal DA pathway. The order of potency against audiogenic seizures was apomorphine greater than ergocornine greater than bromocryptine greater than ergometrine greater than LSD greater than methysergide greater than piribedil while that observed in the rotating mouse model was apomorphine greater than ergometrine greater than ergocornine greater than bromocryptine greater than piribedil. LSD caused only weak circling behaviour even when administered in high doses (greater than 1 mg/kg). Methysergide was ineffective. Prior administration of the neuroleptic agent haloperidol blocked the effect of DA agonists and of ergot alkaloids in both animal models. The possible action of ergot alkaloids as DA agonists is discussed.     

Validation of a new blood-mimicking fluid for use in Doppler flow test objects

PM28A is a major intrinsic protein of the spinach leaf plasma membrane and the major phosphoprotein. Phosphorylation of PM28A is dependent in vivo on the apoplastic water potential and in vitro on submicromolar concentrations of Ca2+. Here, we demonstrate that PM28A is an aquaporin and that its water channel activity is regulated by phosphorylation. Wild-type and mutant forms of PM28A, in which putative phosphorylation sites had been knocked out, were expressed in Xenopus oocytes, and the resulting increase in osmotic water permeability was measured in the presence or absence of an inhibitor of protein kinases (K252a) or of an inhibitor of protein phosphatases (okadaic acid). The results indicate that the water channel activity of PM28A is regulated by phosphorylation of two serine residues, Ser-115 in the first cytoplasmic loop and Ser-274 in the C-terminal region. Labeling of spinach leaves with 32P-orthophosphate and subsequent sequencing of PM28A-derived peptides demonstrated that Ser-274 is phosphorylated in vivo, whereas phosphorylation of Ser-115, a residue conserved among all plant plasma membrane aquaporins, could not be demonstrated. This identifies Ser-274 of PM28A as the amino acid residue being phosphorylated in vivo in response to increasing apoplastic water potential and dephosphorylated in response to decreasing water potential. Taken together, our results suggest an active role for PM28A in maintaining cellular water balance.     

The impact of nuclear analysis on ITER design and licensing

The complexity of nuclear analysis on the design components of ITER is discussed. These analyses include the determination of several nuclear responses and it is shown that these results are not only relevant to the component under examination but have implications for the design of many other, often remote, systems. The contribution of nuclear analysis to the licensing process is discussed. An example is given of how this complexity means that the there is a large set of complementary analyses required to address the concerns of the licensing authorities. It also means that the nuclear analysis must be co-ordinated to ensure that the results are self-consistent and provide an integrated solution.