Low temperature deformation behaviour of ASTM A-203D nuclear structural steel

The steel A-203D in martensitic, tempered martensitic and ferritic-pearlitic microstructural conditions, was deformed in tension at temperatures between 77 to 300 K and at a strain rate of 6.67×10-5 sec-1. The thermal component of the flow stress and the activation parameters were measured as a function of temperature. It was observed that the microstructure did not affect either the thermal part of the flow stress (σ*) or the activation parameters (V* and ΔH) and that its effect was felt only on the athermal component (σμ) of the flow stress. Further the relations of the activation parameters with stress, strain and temperature were found to be consistent with Dorn-Rajnak theory of Peierls mechanism of plastic deformation. In addition measurements of slow-bend and impact transition were also carried out for ferritic-pearlitic structure. Based on these observations, it is shown that the impact transition temperature of this structure can be emperically correlated with the thermal activation parameters

Precipitation hardening in nickel-copper base alloy monel K 500

The occurrence of a significant amount of age hardening, due to the precipitation of the γ' phase, has been demonstrated in the nickel-copper base alloy MONEL K 500. The micro-structure of the precipitation-hardened and deformed alloy has been examined in peak-aged underaged and overaged conditions. An attempt has been made to compare the observed increments in strength in these three aged conditions to those predicted on the basis of relevant theoretical models

Growth and characterization of heteroepitaxial La-substituted BaSnO3_3 films on SrTiO3_3 (001) and SmScO3_3 (110) substrates

Heteroepitaxial growth of BaSnO$_3$ (BSO) and Ba$_{1-x}$La$_x$SnO$_3$ (x = 7 %) (LBSO) thin films on different perovskite single crystal (SrTiO$_3$ (001) and SmScO$_3$ (110)) substrates has been achieved by Pulsed Laser Deposition (PLD) under optimized deposition conditions. X-ray diffraction measurements indicate that the films on either of these substrates are relaxed due to the large mismatch and present a high degree of crystallinity with narrow rocking curves and smooth surface morphology while analytical quantification by proton induced x-ray emission (PIXE) confirms the stoichiometric La transfer from a polyphasic target, producing films with La contents above the bulk solubility limit. The films show degenerate semiconducting behavior on both substrates, with the observed room temperature resistivities, Hall mobilities and carrier concentrations of 4.4 $m \Omega cm$, 10.11 $cm^2 V^{-1} s^{-1}$, and 1.38 $\cdot 10^{20} cm^{-3}$ on SmScO$_3$ and 7.8 $m \Omega cm$, 5.8 $cm^2 V^{-1} s^{-1}$, and 1.36 $\cdot 10^{20} cm^{-3}$ on SrTiO$_3$ ruling out any extrinsic contribution from the substrate. The superior electrical properties observed on the SmScO3 substrate are attributed to reduction in dislocation density from the lower lattice mismatch.Comment: 11 pages, 3 figures, supplementary informations 2 figure

The CAMELS project: Cosmology and Astrophysics with MachinE Learning Simulations

We present the Cosmology and Astrophysics with MachinE Learning Simulations --CAMELS-- project. CAMELS is a suite of 4,233 cosmological simulations of $(25~h^{-1}{\rm Mpc})^3$ volume each: 2,184 state-of-the-art (magneto-)hydrodynamic simulations run with the AREPO and GIZMO codes, employing the same baryonic subgrid physics as the IllustrisTNG and SIMBA simulations, and 2,049 N-body simulations. The goal of the CAMELS project is to provide theory predictions for different observables as a function of cosmology and astrophysics, and it is the largest suite of cosmological (magneto-)hydrodynamic simulations designed to train machine learning algorithms. CAMELS contains thousands of different cosmological and astrophysical models by way of varying $\Omega_m$, $\sigma_8$, and four parameters controlling stellar and AGN feedback, following the evolution of more than 100 billion particles and fluid elements over a combined volume of $(400~h^{-1}{\rm Mpc})^3$. We describe the simulations in detail and characterize the large range of conditions represented in terms of the matter power spectrum, cosmic star formation rate density, galaxy stellar mass function, halo baryon fractions, and several galaxy scaling relations. We show that the IllustrisTNG and SIMBA suites produce roughly similar distributions of galaxy properties over the full parameter space but significantly different halo baryon fractions and baryonic effects on the matter power spectrum. This emphasizes the need for marginalizing over baryonic effects to extract the maximum amount of information from cosmological surveys. We illustrate the unique potential of CAMELS using several machine learning applications, including non-linear interpolation, parameter estimation, symbolic regression, data generation with Generative Adversarial Networks (GANs), dimensionality reduction, and anomaly detection.Comment: 33 pages, 18 figures, CAMELS webpage at https://www.camel-simulations.or

Studies on the Structure of Never-Dried Cotton: Part III-Effect of Humidity during Drying on Fibre Properties

13-17<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The effect of humidity during drying never-dried cotton on the fibre characteristics and collapse of the fibre structure has been studied. The growth of convolutions as a function of fibre moisture has been investigated. The data on the strength uniformity, dye adsorption, water retention, glycerol retention and alkali centrifuge value of different fibre samples dried at different humidities and temperatures suggest that the fibres dried at 40-65% RH show better properties than nature-dried cotton.</span

Structure-property correlation of Zr-base alloys

Zirconium alloys, because of their unique combination of high strength, good corrosion resistance in water and low capture cross-section for thermal neutrons, have become attractive for use as structural materials in the nuclear industry. Presently, Zircaloy-2 and Zircaloy-4 find wide application as fuel and pressure tube materials for water cooled power reactors. In order to understand how the various alloying elements of Zircaloy, namely Sn, Fe, Cr and Ni, affect the mechanical properties, a programme has been initiated to evolve a correlation between chemistry, microstructure and mechanical properties of Zr-alloy containing various amounts of Sn, Fe and Cr. In the present investigation, mechanical properties of Zr-alloys with various addition of Sn, Fe and Cr have been determined at 300 K and 573 K in various metallurgical conditions such as recrystallised annealed, β-quenched, tempered and α-annealed conditions. The study revealed that the reduced tin content dit not affect the mechanical properties as the reduced tin leads to formation of fine precipitates. The mechanical properties were also not altered drastically with the low level of iron and chromium concentrations studied. Cold work and α-annealing after β-quenching resulted in the growth and redistribution of second phase particles. Metallographie studies showed that particle distribution was not uniform. A TEM investigation of the alloys has also been undertaken to study the details of microstructure developed during various heat-treated conditions. It has been found that the β-quenched samples exhibit the most uniform microstructure consisting of acicular alpha phase with lath boundary enriched by solute element and fine intermetallic particle formation. The observed microstructural features together with the mechanical properties data have been compared with the available mechanical properties cum microstructure of Zircaloy

Dynamic strain-ageing of A203D nuclear structural steel

The present investigation deals with the dynamic strain-ageing behaviour of a nuclear structural steel, designated ASTM A203 grade D, in tempered martensitic and ferritic-pearlitic microstructural conditions. The serrated stress-strain curves, characteristic of this phenomenon have been observed in the temperature range 100-200&#176;C, with nominal strain rates varying from 1.33 &#215; 10-5 to 6.66 &#215; 10-4/s. It has been noted that dynamic strain-ageing causes a sharp rise in ultimate strength and work-hardening rate, a marked decrease in ductility and a negative strain-rate sensitivity of the flow stress. In this temperature range, the yield stress also increases with increasing temperature but the rise in ultimate stress is much greater than the rise in yield stress. The temperature and strain-rate dependence of the onset of serrations yields an activation energy of 63 kj/mol (15 kcal/mol), which suggests that the process is controlled by interstitial diffusion, probably of nitrogen, in ferrite. It appears that microstructure does not have any strong influence on the changes in mechanical properties of this steel during dynamic strain-ageing

Quantitation of X-Y homologous genes in patients with schizophrenia by multiplex polymerase chain reaction.

OBJECTIVES: The genetic basis of schizophrenia is obscure. In an XX male patient with schizophrenia we previously showed that one X;Y translocation breakpoint was in pseudoautosomal region 1 (PAR1) with the effect that the proximal segment of PAR1 from the PAR1 boundary to acetylserotonin N-methyl transferase (ASMT) distally was triplicated in this patient. This study determined whether dosage imbalances of X-Y homologous regions in general are associated with schizophrenia. METHODS: A multiplex semi-quantitative polymerase chain reaction assay was developed to quantify MIC2 gene as a representative of PAR1 and compare it with the SYBL1 gene which maps in pseudoautosomal region 2 (PAR2) and protocadherin XY (PCDHXY), located at Xq21.3. Each of these three loci was co-amplified with the autosomal gene MSX2 using Cy5-labelled primers and the products separated by electrophoresis in polyacrylamide gels. Results were expressed as ratios of peak area of the target gene to MSX2 which served as an internal dosage control. RESULTS: Using genomes with sex chromosome aneuploidies, the method was found sensitive enough to detect a two-fold difference in gene copy number. We confirmed the MIC2 triplication in the XX male patient but found no significant difference in gene dosage of MIC2, PCDHXY and SYBL1 in a panel of 17 patients with schizophrenia compared to controls. CONCLUSIONS: No evidence was obtained for gene dosage imbalances in MIC2, PCDHXY and SYBL1 in patients with schizophrenia

Antihyperglycemic Activity of Various Fractions of Cassia auriculata Linn. in Alloxan Diabetic Rats

Present work describes the potent antidiabetic fraction from flowers of Cassia auriculata Linn. Hydromethanolic extract along with its ethyl acetate and n-butanol fractions were evaluated for antidiabetic activity in alloxan-induced diabetes in rats. The n-butanol fraction exhibited significant reduction (p<0.001) in blood glucose levels and was also found effective in restoring the blood lipids and proteins to normal level. The activity was found comparable with standard drug phenformin. The hydromethanolic extract and its fractions were subjected to preliminary qualitative chemical investigations which indicated the presence of phenolic compounds, carbohydrates, tannins, steroids and amino acids