Nano- and microvoid formation in ultrafine-grained martensitic Fe-Ni-Mn steel after severe cold rolling

Severe cold-rolling was applied on solution annealed Fe-Ni-Mn steel with fully lath martensite structure to obtain ultrafine-grained structure. Field emission scanning electron microscopy and high resolution transmission electron microscopy (HRTEM) were employed to investigate the microstructural evolution after severe cold-rolling. HRTEM images showed the typical deformed structure consisting of lamellar dislocation cell blocks. HRTEM study also revealed strain-induced reverse martensitic transformation (activated during grain refinement). It was assumed that severe plastic deformation route and related deformation mode were responsible for microstructural evolutions. X-ray diffraction (XRD) diagram revealed 7% (volume fraction) reverted austenite after final deformation pass. Moreover, HRTEM images revealed nano-void nucleation at the interface of severely deformed martensite and reverted austenite presumably due to high strain energy of misfit and molar volume difference between the austenite and the martensite. It seems that the coalescence of nano-voids could lead to the formation of microvoids in the microstructure.     

A Synergic Blend of Newly Isolated <Emphasis Type="Italic">Pseudomonas mandelii</Emphasis> KJLPB5 and [hmim]Br for Chemoselective 2° Aryl Alcohol Oxidation in H<Subscript>2</Subscript>O<Subscript>2</Subscript>: Synthesis of Aryl Ketone or Aldehydes via Sequential Dehydration-Oxidative C=C Cleavage

Abstract  

Pseudomonas mandelii KJLPB5 is reported for the oxidation of aryl alcohols in ionic liquid [hmim]Br (1-hexyl-3-methyl imidazolium bromide) with H₂O₂. With a slight alteration of reaction conditions, the developed protocol leads either to (i) chemoselective oxidation of 2° aryl alcohols over 1° and aliphatic counterparts or (ii) direct one pot-two step sequential conversion of 2° aryl alcohols into corresponding one or two carbons shorter aryl aldehydes through oxidative cleavage pathway, thus providing a new facet to metal-free oxidations. The key operational parameters such as substrate concentration, incubation temperature, incubation time, ionic liquid type and ionic liquid concentration are also optimized.     

A Review on the Development of XRD in Ferrite Nanoparticles

Journal of Superconductivity and Novel Magnetism - In the present study, an overview of the aspects of X-ray diffraction (XRD) in ferrite has been explored. Ferrite nanoparticles have a wide range...     

Design and energy dissipation analysis of simple QCA multiplexer for nanocomputing

The Journal of Supercomputing - The multiplexer is an integral design component of the conventional CMOS technology and modern QCA nanotechnology. It is also an elementary building block of...     

Enhanced Droplet Erosion Resistance of Laser Treated Nano Structured TWAS and Plasma Ion Nitro-Carburized Coatings for High Rating Steam Turbine Components

This article deals with surface modification of twin wire arc sprayed (TWAS) and plasma ion nitro-carburized X10CrNiMoV1222 steel using high power diode laser (HPDL) to overcome water droplet erosion occurring in low pressure steam turbine (LPST) bypass valves and LPST moving blades used in high rating conventional, critical, and super critical thermal power plants. The materials commonly used for high rating steam turbines blading are X10CrNiMoV1222 steel and Ti6Al4V titanium alloy. The HPDL surface treatment on TWAS coated X10CrNiMoV1222 steel as well as on plasma ion nitro-carburized steel has improved water droplet resistance manifolds. This may be due to combination of increased hardness and toughness as well as the formation of fine grained structure due to rapid heating and cooling rates associated with the laser surface treatment. The water droplet erosion test results along with their damage mechanism are reported in this article.     

Changes in free nucleotides, nucleosides and bases during preparation of pre-cooked dehdyrated minced meats

Changes in free nucleotides, nucleosides and bases during preparation of pre-cooked dehydrated minced meats from goat and sheep are reported. Major changes took place during cooking stage only; the changes during dehydration were relatively minor. Addition of EDTA at 500 ppm level significantly reduced the rate of dephosphorylation during curing process. Concentration of free nucleotides and related compounds were very low in commercially prepared accelerated freeze dried meat chunks.     

Efficient synthesis of hydroxystyrenes via biocatalytic decarboxylation/deacetylation of substituted cinnamic acids by newly isolated Pantoea agglomerans strains

BACKGROUND: Decarboxylation of substituted cinnamic acids is a predominantly followed pathway for obtaining hydroxystyrenes—one of the most extensively explored bioactive compounds in the food and flavor industry (e.g. FEMA GRAS approved 4‐vinylguaiacol). For this, mild and green strategies providing good yields with high product selectivity are needed. RESULTS: Two newly isolated bacterial strains, i.e. Pantoea agglomerans KJLPB4 and P. agglomerans KJPB2, are reported for mild and effective decarboxylation of substituted cinnamic acids into corresponding hydroxystyrenes. Key operational parameters for the process, such as incubation temperature, incubation time, substrate concentration and effect of co‐solvent, were optimized using ferulic acid as a model substrate. With strain KJLPB4, 1.51 g L^?1 4‐vinyl guaiacol (98% yield) was selectively obtained from 2 g L^?1 ferulic acid at 28 °C after 48 h incubation. However, KJPB2 provided vanillic acid in 85% yield after 72 h following the oxidative decarboxylation pathway. In addition, KJLPB4 was effectively exploited for the deacetylation of acetylated α‐phenylcinnamic acids, providing corresponding compounds in 65–95% yields. CONCLUSION: Two newly isolated microbial strains are reported for the mild and selective decarboxylation of substituted cinnamic acids into hydroxystyrenes. Preparative‐scale synthesis of vinyl guaiacol and utilization of renewable feedstock (ferulic acid extracted from maize bran) have been demonstrated to enhance the practical utility of the process. Copyright © 2011 Society of Chemical Industry