Effect of Grain Boundary Character Distribution on the Impact Toughness of 410NiMo Weld Metal

Grain boundary character distributions in 410NiMo weld metal were studied in the as-welded, first-stage, and second-stage postweld heat treatment (PWHT) conditions, and these were correlated with the Charpy-V impact toughness values of the material. The high impact toughness values in the weld metal in the as-welded and first-stage PWHT conditions compared to that in the second-stage condition are attributed to the higher fraction of low-energy I pound boundaries. A higher volume fraction of retained austenite and coarser martensite after second-stage PWHT accompanied by the formation of the ideal cube component in the 2-hour heat-treated specimen led to a reduction in the toughness value. A subsequent increase in the PWHT duration at 873 K (600 A degrees C) enhanced the formation of {111}aOE (c) 112 >, which impedes the adverse effect of the cubic component, resulting in an increase in the impact toughness. In addition to this, grain refinement during 4-hour PWHT in the second stage also increased the toughness of the weld metal

Antioxidant, Anti-inflammatory and Cytotoxicity of Phaleria macrocarpa (Boerl.) Scheff Fruit

<p>Abstract</p> <p>Background</p> <p><it>Phaleria macrocarpa </it>(Scheff.) Boerl (Thymelaceae) originates from Papua Island, Indonesia and grows in tropical areas. The different parts of the fruit of <it>P. macrocarpa </it>were evaluated for antioxidant, anti-inflammatory, and cytotoxic activities.</p> <p>Methods</p> <p><it>Phaleria macrocarpa </it>fruit were divided into pericarp, mesocarp and seed. All parts of the fruit were reflux extracted with methanol. The antioxidant activity of the extracts were characterized in various <it>in vitro </it>model systems such as FTC, TBA, DPPH radical, reducing power and NO radical. Anti-inflammatory assays were done by using NO production by macrophage RAW 264.7 cell lines induced by LPS/IFN-γ and cytotoxic activities were determined by using several cancer cell lines and one normal cell line</p> <p>Results</p> <p>The results showed that different parts (pericarp, mesocarp, and seed) of <it>Phaleria macrocarpa </it>fruit contain various amount of total phenolic (59.2 ± 0.04, 60.5 ± 0.17, 47.7 ± 1.04 mg gallic acid equivalent/g DW) and flavonoid compounds (161.3 ± 1.58, 131.7 ± 1.66, 35.9 ± 2.47 mg rutin equivalent/g DW). Pericarp and mesocarp showed high antioxidant activities by using DPPH (71.97%, 62.41%), ferric reducing antioxidant power (92.35%, 78.78%) and NO scavenging activity (65.68%, 53.45%). Ferric thiocyanate and thiobarbituric acid tests showed appreciable antioxidant activity in the percentage hydroperoxides inhibitory activity from pericarp and mesocarp in the last day of the assay. Similarly, the pericarp and mesocarp inhibited inducible nitric oxide synthesis with values of 63.4 ± 1.4% and 69.5 ± 1.4% in macrophage RAW 264.7 cell lines induced by LPS/IFN-γ indicating their notable anti-inflammatory potential. Cytotoxic activities against HT-29, MCF-7, HeLa and Chang cell lines were observed in all parts.</p> <p>Conclusions</p> <p>These results indicated the possible application of <it>P. macrocarpa </it>fruit as a source of bioactive compounds, potent as an antioxidant, anti inflammatory and cytotoxic agents.</p

Antioxidant activity of twenty five plants from Colombian biodiversity

The antioxidant activity of the crude n-hexane, dichloromethane, and methanol extracts from 25 species belonging to the Asteraceae, Euphorbiaceae, Rubiaceae, and Solanaceae families collected at natural reserves from the Eje Cafetero Ecorregión Colombia, were evaluated by using the spectrophotometric 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging method. The strongest antioxidant activities were showed by the methanol and dichloromethane extracts from the Euphorbiaceae, Alchornea coelophylla (IC50 41.14 mg/l) and Acalypha platyphilla (IC50 111.99 mg/l), respectively. These two species had stronger DPPH radical scavenging activities than hydroquinone (IC50 151.19 mg/l), the positive control. The potential use of Colombian flora for their antioxidant activities is discussed

Classification on Stiefel and Grassmann manifolds via maximum Likelihood estimation of matrix distributions

© 2016 IEEE. Matrix manifolds such as Stiefel and Grassmann manifolds have been widely used in modern computer vision. This paper is concerned with the problem of classifying such manifold-valued data, based on the maximum likelihood estimation for the parametric probability density functions defined on the manifolds. By using a new way of computing normalisation constants for the matrix Langevin distribution function, defined for the data on Stiefel manifold, and the Fisher-Bingham density function on Grassmann manifold, we proposed a simple way to estimate the parameters in the distribution and demonstrated on real world datasets that the proposed method is efficient and more accurate. Our method uses asymptotic and Taylor series approximations, with good accuracy estimate

MLE-Based Learning on Grassmann Manifolds

© 2016 IEEE. In this paper we focus on Maximum Likelihood Estimation (MLE) technique for classification on Grassmann manifolds using matrix variate Bingham density function. Unlike the conventional techniques for multivariate distributions in the existing literature e.g., Markov chain Monte Carlo (MCMC) sampling methods, non-parametric methods, Expectation Maximisation (EM) iterative methods or exact methods, we demonstrate a new way of parametric modelling for classification that is strictly based on normalising constant. The evaluation of normalising constant is based on the matrix-variate Saddle Point Approximation (SPA). The Maximum Likelihood Estimation (MLE) is directly employed on the proposed manifold based Bingham density function via simple Bayesian classifier. For numerical experiments a 3-class classification example is considered by using real world Caltech 101 and DynTex++ database. We have compared our average classification accuracy rate with the baseline results taken from the existing state of the art techniques, and found that our method outperforms or at least best comparable

GPR signal attenuation through fragmented rock

© 2016 Institute of Materials, Minerals and Mining and The AusIMM. This paper presents results on detecting large rock fragments in rock piles using ground penetrating radar (GPR). The authors are researching sensors to augment the image provided to the remote operator, assisting with detection of oversized fragments beneath the surface. The attenuation of the GPR signal was calculated over the band 0-3 GHz from the signal energy in the frequency domain. The results show that attenuation measurement allowed the samples which included a large fragment to be differentiated from samples only containing smaller rock fragments. By combining velocity analysis with attenuation the rock samples can be further differentiated from samples containing air pockets or irregular surfaces. The combination of attenuation and signal velocity allowed prediction rates to detect the presence of large rock fragments over 93% correctly in laboratory testing