982 research outputs found

    Single sided single pass submerged arc welding of austenitic stainless steel

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    The weld metal produced from a series of high productivity welds of 316LN austenitic stainless steel plate was examined to evaluate the effects of the use of a higher heat input process (> 2.5kJ/mm).This high heat input process was aimed at maximising single sided weld metal penetration in a single pass using simple square edge preparations and minimising time consuming handling operations. The evaluation was undertaken by correlating the local microstructure with the local toughness and microhardness of the cap, middle and root of the weld. It was established that the intermetallic phases / carbides present did not appear to have a significantly adverse effect on either corrosion or toughness. The phases observed and confirmed by the use of SAED were predominantly chi (χ) with some sigma( σ). No identifications were made of M23C6 which was observed in other studies of 316LN welds. A series of impact tests with variations in the notch positions showed that the thickness of the delta ferrite had an effect on the weld metal toughness. As a result of this work it was established that similar volume fractions of delta ferrite did not necessarily produce similar levels of weld metal toughness, but ferrite thickness did appear to have a contributory effect. Welding of 316LN stainless steel with a single sided single pass submerged arc welding process was satisfactorily undertaken up to 20mm plate thickness without preheat or post weld heat treatment. The ability to achieve this resulted in significant economic savings within the process for ship panel production combined with satisfactory weld metal properties

    Pnc1 piggy-back import into peroxisomes relies on Gpd1 homodimerisation.

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    Peroxisomes are eukaryotic organelles that posttranslationally import proteins via one of two conserved peroxisomal targeting signal (PTS1 or 2) mediated pathways. Oligomeric proteins can be imported via these pathways but evidence is accumulating that at least some PTS1-containing monomers enter peroxisomes before they assemble into oligomers. Some proteins lacking a PTS are imported by piggy-backing onto PTS-containing proteins. One of these proteins is the nicotinamidase Pnc1, that is co-imported with the PTS2-containing enzyme Glycerol-3-phosphate dehydrogenase 1, Gpd1. Here we show that Pnc1 co-import requires Gpd1 to form homodimers. A mutation that interferes with Gpd1 homodimerisation does not prevent Gpd1 import but prevents Pnc1 co-import. A suppressor mutation that restores Gpd1 homodimerisation also restores Pnc1 co-import. In line with this, Pnc1 interacts with Gpd1 in vivo only when Gpd1 can form dimers. Redirection of Gpd1 from the PTS2 import pathway to the PTS1 import pathway supports Gpd1 monomer import but not Gpd1 homodimer import and Pnc1 co-import. Our results support a model whereby Gpd1 may be imported as a monomer or a dimer but only the Gpd1 dimer facilitates co-transport of Pnc1 into peroxisomes

    A Study in Depth of f0(1370)

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    Claims have been made that f0(1370) does not exist. The five primary sets of data requiring its existence are refitted. Major dispersive effects due to the opening of the 4pi threshold are included for the first time; the sigma -> 4pi amplitude plays a strong role. Crystal Barrel data on pbar-p -> 3pizero at rest require f0(1370) signals of at least 32 and 33 standard deviations in 1S0 and 3P1 annihilation respectively. Furthermore, they agree within 5 MeV for mass and width. Data on pbar-p -> eta-eta-pizero agree and require at least a 19 standard deviation contribution. This alone is sufficient to demonstrate the existence of f0(1370). BES II data for J/Psi -> phi-pi-pi contain a visible f0(1370) signal > 8 standard devations. In all cases, a resonant phase variation is required. The possibility of a second pole in the sigma amplitude due to the opening of the 4pi channel is excluded. Cern-Munich data for pi-pi elastic scattering are fitted well with the inclusion of some mixing between sigma, f0(1370) and f0(1500). The pi-pi widths for f2(1565), rho3(1690), rho3(1990) and f4(2040) are determined.Comment: 25 pages, 22 figures. Typos corrected in Eqs 2 and 7. Introduction rewritten. Conclusions unchange

    Five-loop renormalization-group expansions for the three-dimensional n-vector cubic model and critical exponents for impure Ising systems

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    The renormalization-group (RG) functions for the three-dimensional n-vector cubic model are calculated in the five-loop approximation. High-precision numerical estimates for the asymptotic critical exponents of the three-dimensional impure Ising systems are extracted from the five-loop RG series by means of the Pade-Borel-Leroy resummation under n = 0. These exponents are found to be: \gamma = 1.325 +/- 0.003, \eta = 0.025 +/- 0.01, \nu = 0.671 +/- 0.005, \alpha = - 0.0125 +/- 0.008, \beta = 0.344 +/- 0.006. For the correction-to-scaling exponent, the less accurate estimate \omega = 0.32 +/- 0.06 is obtained.Comment: 11 pages, LaTeX, no figures, published versio

    Equidistribution of expanding translates of curves and Dirichlet's theorem on Diophantine approximation

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    We show that for almost all points on any analytic curve on R^{k} which is not contained in a proper affine subspace, the Dirichlet's theorem on simultaneous approximation, as well as its dual result for simultaneous approximation of linear forms, cannot be improved. The result is obtained by proving asymptotic equidistribution of evolution of a curve on a strongly unstable leaf under certain partially hyperbolic flow on the space of unimodular lattices in R^{k+1}. The proof involves ergodic properties of unipotent flows on homogeneous spaces.Comment: 26 page

    Antimicrobial Potential of Plastic Films Incorporated with Sage Extract on Chicken Meat

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    The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in prolonging the storage of chicken breast meat without affecting their quality

    Casimir scaling of SU(3) static potentials

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    Potentials between static colour sources in eight different representations are computed in four dimensional SU(3) gauge theory. The simulations have been performed with the Wilson action on anisotropic lattices where the renormalised anisotropies have been determined non-perturbatively. After an extrapolation to the continuum limit we are able to exclude any violations of the Casimir scaling hypothesis that exceed 5% for source separations of up to 1 fm.Comment: 12 pages, 10 figures, RevTeX, v2: 1 reference added, more explanation about advantages of anisotrop

    Epigenome-wide association of PTSD from heterogeneous cohorts with a common multi-site analysis pipeline

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    Compelling evidence suggests that epigenetic mechanisms such as DNA methylation play a role in stress regulation and in the etiologic basis of stress related disorders such as Post traumatic Stress Disorder (PTSD). Here we describe the purpose and methods of an international consortium that was developed to study the role of epigenetics in PTSD. Inspired by the approach used in the Psychiatric Genomics Consortium, we brought together investigators representing seven cohorts with a collective sample size of N = 1147 that included detailed information on trauma exposure, PTSD symptoms, and genome-wide DNA methylation data. The objective of this consortium is to increase the analytical sample size by pooling data and combining expertise so that DNA methylation patterns associated with PTSD can be identified. Several quality control and analytical pipelines were evaluated for their control of genomic inflation and technical artifacts with a joint analysis procedure established to derive comparable data over the cohorts for meta-analysis. We propose methods to deal with ancestry population stratification and type I error inflation and discuss the advantages and disadvantages of applying robust error estimates. To evaluate our pipeline, we report results from an epigenome-wide association study (EWAS) of age, which is a well-characterized phenotype with known epigenetic associations. Overall, while EWAS are highly complex and subject to similar challenges as genome-wide association studies (GWAS), we demonstrate that an epigenetic meta-analysis with a relatively modest sample size can be well-powered to identify epigenetic associations. Our pipeline can be used as a framework for consortium efforts for EWAS
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