Flywheel energy storage system with homopolar electrodynamic magnetic bearing

The goal of this research was to evaluate the potential of homopolar electrodynamic magnetic bearings for flywheel energy storage systems (FESSs). The primary target was a FESS for Low Earth Orbit (LEO) satellites; however, the design can also be easily adapted for Earth-based applications. The main advantage of Homopolar Electrodynamic Bearings compared to more conventional Active Magnetic Bearings (AMB) is simplicity and very low power rating of its electronics, resulting in higher system reliability - a critical factor for space applications. For commercial applications this technologies may also be found very attractive due to a potentially lower cost compared to AMB.Center for Electromechanic

EP-1036: Stereotactic radiotherapy for moving targets with the active breathing control

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Inactivation and Secondary Structure in the D4/S4-5 Region of the SkM1 Sodium Channel

The D4/S4-5 interhelical region plays a role in sodium channel fast inactivation. Examination of S4-5 primary structure in all domains suggests a possible amphipathic helical conformation in which a conserved group of small hydrophobic residues occupies one contiguous surface with a more variable complement of nonpolar and polar residues on the opposite face. We evaluated this potential structure by replacing each residue in D4/S4-5 of the rat SkM1 skeletal muscle sodium channel with substitutions having different side chain properties. Of the 63 mutations analyzed, 44 produced functional channels. P1473 was intolerant of substitutions. Nonpolar substitutions in the conserved hydrophobic region were functionally similar to wild type, while charged mutations in this region before P1473 were nonfunctional. Charged mutations at F1466, M1469, M1470, and A1474, located on the opposite surface of the predicted helix, produced functional channels with pronounced slowing of inactivation, shifted voltage dependence of steady-state inactivation, and increased rate of recovery from inactivation. The substituted-cysteine-accessibility method was used to probe accessibility at each position. Residues L1465, F1466, A1467, M1469, M1470, L1472, A1474, and F1476C were easily accessible for modification by sulfhydryl reagents; L1464, L1468, S1471, and L1475 were not accessible within the time frame of our measurements. Molecular dynamics simulations of residues A1458 to N1477 were then used to explore energetically favorable local structures. Based on mutagenesis, substituted-cysteine-accessibility method, and modeling results, we suggest a secondary structure for the D4/S4-5 region in which the peptide chain is α-helical proximal to P1473, bends at this residue, and may continue beyond this point as a random coil. In this configuration, the entire resultant loop is amphipathic; four residues on one surface could form part of the binding site for the inactivation particle

Curing of epoxy resin DER-331by Hexakis (4-acetamidophenoxy) cyclotriphosphazene and properties of the prepared composition

The method of optical wedge revealed that the optimum temperature for compatibility of hexakis(4-acetamidophenoxy)cyclotriphosphazene (ACP) and DER-331 epoxy resin is in the range of 220–260◦C. The interdiffusion time of components at these temperatures is about 30 min. The TGA and differential scanning calorimetry (DSC) methods revealed the curing temperature of 280◦C for thiscomposition. IRspectroscopyconfirmedthatthereactionbetweentheresinandACPiscompleted within 10 mi

Evidence of neutral transcriptome evolution in plants

The transcriptome of an organism is its set of gene transcripts (mRNAs) at a defined spatial and temporal locus. Because gene expression is affected markedly by environmental and developmental perturbations, it is widely assumed that transcriptome divergence among taxa represents adaptive phenotypic selection. This assumption has been challenged by neutral theories which propose that stochastic processes drive transcriptome evolution. To test for evidence of neutral transcriptome evolution in plants, we quantified 18 494 gene transcripts in nonsenescent leaves of 14 taxa of Brassicaceae using robust cross-species transcriptomics which includes a two-step physical and in silicobased normalization procedure based on DNA similarity among taxa. Transcriptome divergence correlates positively with evolutionary distance between taxa and with variation in gene expression among samples. Results are similar for pseudogenes and chloroplast genes evolving at different rates. Remarkably, variation in transcript abundance among root-cell samples correlates positively with transcriptome divergence among root tissues and among taxa. Because neutral processes affect transcriptome evolution in plants, many differences in gene expression among or within taxa may be nonfunctional, reflecting ancestral plasticity and founder effects. Appropriate null models are required when comparing transcriptomes in space and time

Nucleon-induced fission cross-sections of tantalum and separated tungsten isotopes and "compound nucleus" effect in intermediate energy region

Neutron- and proton-induced fission cross-sections of separated isotopes of tungsten (182W, 183W, 184W, and 186W) and 181Ta relative to 209Bi have been measured in the incident nucleon energy region 50 - 200 MeV using fission chambers based on thin-film breakdown counters (TFBC) using quasi-monoenergetic neutrons from the 7Li(p,n) reaction and at the proton beams of The Svedberg Laboratory (TSL), Uppsala University (Uppsala, Sweden). The results are compared with predictions by the CEM03.01 event generator, as well as with the recent data for nuclei in the lead-bismuth region. The effect of "compound nucleus" in the intermediate energy region is discussed, displaying in exponential dependence of nucleon-induced fission cross-sections on the parameter Z^2/A of the composite system (projectile+target nucleus), and in other characteristics of the fission process for which parameter Z^2/A plays a role similar to the one of the usual liquid-drop parameter Z^2/A of compound nuclei.Comment: 4 pages, 3 figures, 2 tables, only pdf file, to be published in Proc. Int. Conf. on Nucl. Data for Sci. and Technology (ND2007), Nice, France, April 22-27, 200

The western Mediterranean region provided the founder population of domesticated narrow-leafed lupin

Key message: This study revealed that the western Mediterranean provided the founder population for domesticated narrow-leafed lupin and that genetic diversity decreased significantly during narrow-leafed lupin domestication. Abstract: The evolutionary history of plants during domestication profoundly shaped the genome structure and genetic diversity of today’s crops. Advances in next-generation sequencing technologies allow unprecedented opportunities to understand genome evolution in minor crops, which constitute the majority of plant domestications. A diverse set of 231 wild and domesticated narrow-leafed lupin (Lupinus angustifolius L.) accessions were subjected to genotyping-by-sequencing using diversity arrays technology. Phylogenetic, genome-wide divergence and linkage disequilibrium analyses were applied to identify the founder population of domesticated narrow-leafed lupin and the genome-wide effect of domestication on its genome. We found wild western Mediterranean population as the founder of domesticated narrow-leafed lupin. Domestication was associated with an almost threefold reduction in genome diversity in domesticated accessions compared to their wild relatives. Selective sweep analysis identified no significant footprints of selection around domestication loci. A genome-wide association study identified single nucleotide polymorphism markers associated with pod dehiscence. This new understanding of the genomic consequences of narrow-leafed lupin domestication along with molecular marker tools developed here will assist plant breeders more effectively access wild genetic diversity for crop improvement