Spin-transfer switching and low-field precession in exchange-biased spin valve nano-pillars

Using a three-dimensional focused-ion beam lithography process we have fabricated nanopillar devices which show spin transfer torque switching at zero external magnetic fields. Under a small in-plane external bias field, a field-dependent peak in the differential resistance versus current is observed similar to that reported in asymmetrical nanopillar devices. This is interpreted as evidence for the low-field excitation of spin waves which in our case is attributed to a spin-scattering asymmetry enhanced by the IrMn exchange bias layer coupled to a relatively thin CoFe fixed layer.Comment: 11 pages, 4 figures. To appear in APL, April 200

Fuel quality/processing study. Volume 4: On site processing studies

Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded

The Route of Sir John Franklin's Third Arctic Expedition: An Evaluation and Test of an Alternative Hypothesis

An archaeological survey to aid in the determination of the exact route of the last Sir John Franklin expedition following its overwintering at Beechey Island in 1845-46 was conducted in June 1982. The survey was designed to test the hypothesis that the expedition sailed from Beechey Island south to King William Island via McClintock Channel, rather than through Peel Sound and Franklin Strait, as is generally accepted. Surveyed areas included Kilian, Stefansson, and northeast Victoria Islands in northwest McClintock Channel, and Russell and northern Prince of Wales Islands to the northeast of McClintock Channel. Although three cairns associated with Austin's searching expedition of 1850-51 were located, as well as several prehistoric and historic Inuit sites, no structures or materials associated with the Franklin expedition were identified. While inconclusive, the survey essentially completes the examination of coastlines along which the Franklin expedition may have sailed.Key words: Sir John Franklin, route of third arctic expedition, McClintock ChannelEn juin 1982, on a effectué une étude archéologique destinée à permettre de retracer la route empruntée par la dernière expédition de sir John Franklin après le long hivernage de 1845-46 à l'île Beechey. L'étude avait pour but de vérifier l'hypothèse selon laquelle l'expédition avait navigué de l'île Beechey en direction du sud vers l'île du Roi-Guillaume via le chenal McClintock, plutôt qu'à travers le détroit de Peel et celui de Franklin, comme on le pense habituellement. Les régions de l'étude comprenaient les îles Kilian et Stefansson et le nord-est de l'île Victoria dans la partie nord-ouest du chenal McClintock, ainsi que l'île Russell et la partie septentrionale de l'île du Prince-de-Galles au nord-est du chenal McClintock. Bien qu'on ait localisé trois cairns datant de l'expédition de recherche menée par Austin en 1850-51, ainsi que divers sites inuit préhistoriques et historiques, on n'a pu identifier ni structure ni matériaux remontant à l'expédition Franklin. Si l'étude n'a pas abouti à une conclusion définitive, elle a du moins permis de compléter l'examen du rivage côtier le long duquel l'expédition Franklin a pu naviguer.Mots clés: sir John Franklin, route de la troisième expédition arctique, chenal McClintoc

Calibrating Type Ia Supernovae using the Planetary Nebula Luminosity Function I. Initial Results

We report the results of an [O III] lambda 5007 survey for planetary nebulae (PN) in five galaxies that were hosts of well-observed Type Ia supernovae: NGC 524, NGC 1316, NGC 1380, NGC 1448 and NGC 4526. The goals of this survey are to better quantify the zero-point of the maximum magnitude versus decline rate relation for supernovae Type Ia and to validate the insensitivity of Type Ia luminosity to parent stellar population using the host galaxy Hubble type as a surrogate. We detected a total of 45 planetary nebulae candidates in NGC 1316, 44 candidates in NGC 1380, and 94 candidates in NGC 4526. From these data, and the empirical planetary nebula luminosity function (PNLF), we derive distances of 17.9 +0.8/-0.9 Mpc, 16.1 +0.8/-1.1 Mpc, and 13.6 +1.3/-1.2 Mpc respectively. Our derived distance to NGC 4526 has a lower precision due to the likely presence of Virgo intracluster planetary nebulae in the foreground of this galaxy. In NGC 524 and NGC 1448 we detected no planetary nebulae candidates down to the limiting magnitudes of our observations. We present a formalism for setting realistic distance limits in these two cases, and derive robust lower limits of 20.9 Mpc and 15.8 Mpc, respectively. After combining these results with other distances from the PNLF, Cepheid, and Surface Brightness Fluctuations distance indicators, we calibrate the optical and near-infrared relations for supernovae Type Ia and we find that the Hubble constants derived from each of the three methods are broadly consistent, implying that the properties of supernovae Type Ia do not vary drastically as a function of stellar population. We determine a preliminary Hubble constant of H_0 = 77 +/- 3 (random) +/- 5 (systematic) km/s/Mpc for the PNLF, though more nearby galaxies with high-quality observations are clearly needed.Comment: 25 pages, 12 figures. Accepted for publication by the Astrophysical Journal. Figures degraded to comply with limit. Full paper is available at: http://www.as.ysu.edu/~jjfeldme/pnlf_Ia.pd

CBU_1932: A Hypothetical DNA-Binding Protein of the Q Fever Pathogen Coxiella Burnetii

Coxiella burnetii is an obligate intracellular bacterial pathogen that resides within a lysosome-like acidic compartment of the eukaryotic host cell and may cause acute and chronic human infections.  Our recent transcriptome analysis of C. burnetii demonstrated that the CBU_1932 open reading frame displayed an exceptionally high transcript level at 11,481 transcripts per million (TPM), well above average transcript quantity for remaining ORFs in the genome.  Due to it’s high transcript level we hypothesize the corresponding protein may play an important role for Coxiella.  Analysis of the CBU_1932 locus indicates that one of the adjacent ORFs, CBU_1933 is a hypothetical DNA binding protein.  The protein encoded by CBU_1932 ORF consists of 66 amino acid residues with an unusually high percentage (42%) of residues being basic, including 20 lysines.  Using BLAST algorithms we found CBU_1932 had no similarity with currently defined proteins, but has orthologues in other human intracellular pathogens such as Legionella and Chlamydia. Due to the high number of basic residues in CBU_1932, and linkage with a hypothetical DNA binding protein (CBU_1933), we hypothesize that CBU_1932 may also encode a protein involved with binding DNA or other negatively charged substrates.  To address this hypothesis, we are in the process of cloning the 201-base pair CBU_1932 ORF into pMAL-c5x expression plasmid and analyzing the recombinant protein using DNA-binding protocols including electrophoretic mobility-shift assay EMSA.  We are confident that characterization of this high-level transcript/highly basic protein will lead to a better understanding of the unique metabolism of Coxiella and other intracellular pathogens