Effect of Vanadium Microalloying on the HAZ Microstructure and Properties of Low Carbon Steels

Four Steels,C-Mn-0.05V,C-Mn-0.11V,C-Mn-0.03Nb and C-Mn were subjected to heat treatment to simulate the microstructure of a coarse grained heat affected zone (CGHAZ) and an intercritically reheated coarse grained heat affected zone (ICCGHAZ).This involved reheating to 1350°C,rapid cooling (Δt 8/5 =24s) to room temperature and then reheating to either 750°C or 800°C.The toughness of the HAZs was assessed using both Charpy and CTOD tests.Microstructural features were characterised by optical,scanning` and transmission electron microscopy.Fractographic examinations of the Charpy and CTOD specimens were carried out to understand the micromechanism of fracture under different microstructural and test conditions.The CGHAZ toughness was similar for the steels except that Steel C-Mn-0.05V had a slightly lower ITT compared to the others.The toughness deteriorated in the ICCGHAZ for all the steels,again Steel C-Mn-0.05V had a superior toughness compared to the other three steels in both ICCGHAZ conditions.Raising the level of vanadium to 0.11% caused a decrease in ICCGHAZ toughness.Steel C-Mn-Nb exhibited a greater degradation of impact toughness after the intercritical cycles.The presence of M-A constituents was the dominant factor in determining the toughness of the ICCGHAZs.The size and area fraction of the M-A constituents were the smallest in Steel C-Mn-0.05V.Increasing vanadium level to 0.11% resulted in a greater area fraction of the M-A constituents,larger average and maximum sizes of M-A particles,and significantly more fields containing the M-A.The addition of 0.031% Nb produced the largest M-A particles and the greatest area fraction for the steels tested.     

Density measurement of thin-films for micro-electromechanical systems using micro-cantilever structures

The use of micro-cantilever test structures for determining the density of thin film materials is reported. A range of micro-cantilever test structures has been fabricated using silicon, silicon nitride and silicon carbide which are materials that are commonly used in the fabrication of micro-electromechanical systems. The density of each material was determined by combining load-deflection and resonant frequency measurements, and using the Euler-Bernoulli equation for single clamped beams. The density values obtained were 2.35, 3.16 and 3.18 g/cm³ for silicon, silicon carbide and silicon nitride respectively. These values of density for these thin films agree very well with the values quoted in the literature.     

From the viewpoint of a client

Collaboration between choreographers and architects still usually takes the traditional form of the latter designing sets for the former, while research on the relationship between architecture and dance is scant. One of the few examples of a choreographer working with then-current architectural concerns is William Forsythe and the Ballett Frankfurt in the late 1980s, particularly in Enemy in the Figure (1989) and Limb's Theorem (1990). These pieces show a profound understanding of and engagement with architectural issues then being addressed by Daniel Libeskind. Forsythe's interest in Libeskind was not his ‘deconstruction’, as has often been asserted, but in his operations on drawing. Their coincidence of intellectual interests and resulting friendship allows us to see clearly how concerns in architecture were also explored through the medium of ballet. It is a reminder too of a period, postmodernism, when architecture led theoretical discussions.     

Biocatalytically Triggered Co‐Assembly of Two‐Component Core/Shell Nanofibers

For the development of applications and novel uses for peptide nanostructures, robust routes for their surface functionalization, that ideally do not interfere with their self‐assembly properties, are required. Many existing methods rely on covalent functionalization, where building blocks are appended with functional groups, either pre‐ or post‐assembly. A facile supramolecular approach is demonstrated for the formation of functionalized nanofibers by combining the advantages of biocatalytic self‐assembly and surfactant/gelator co‐assembly. This is achieved by enzymatically triggered reconfiguration of free flowing micellar aggregates of pre‐gelators and functional surfactants to form nanofibers that incorporate and display the surfactants’ functionality at the surface. Furthermore, by varying enzyme concentration, the gel stiffness and supramolecular organization of building blocks can be varied.     

Effects of cobalt addition on structural,thermal and electrical properties of praseodymium-yttrium co-doped barium cerates

Effects of cobalt addition on structural, thermal and electrical properties of praseodymium-yttrium co-doped barium cerates have been investigated. Relative densities >98 % have been achieved after sintering at 1400 °C or 1500 °C for only 1 h. All studied compounds are stable in ambient air up to the measured 900 °C and, in reducing atmosphere (both wet and dry 5 % H₂-Ar) up to the measured 800 °C. The Co-free sample (BaCe_0.7Y_0.2Pr_0.1O_3-δ) exhibits the highest conductivity of 1.21?×?10^?2 S cm^?1 at 700 °C in air while the corresponding cobalt containing sample (BaCe_0.7Y_0.175Pr_0.1Co_0.025O_3?δ) has a conductivity of 9.85?×?10^?3 S cm^?1 at 700 °C in air. Cobalt addition allows the ability to retain much larger amounts of water to be retained as suggested by the higher conductivities obtained in wet hydrogen compared to the values in dry reducing atmosphere. This latter phenomenon is of special interest as it suggests the possibility of higher ionic conductivities in water-containing atmosphere and would benefit to intermediate- and high-temperature solid oxide fuel cells and/or electrolysers. The thermal expansion coefficients for the Co-free and Co-containing samples were around 12.0?×?10^?6 K^?1 between 25 and 1000 °C.     

Influence of partial substitution of wheat flour with vetch (Lathyrus sativus L) flour on quality characteristics of doughnuts

Partial substitution of wheat flour (Triticum aestivum) with vetch flour (Lathyrus sativus L) at the levels of 5, 10, 15 and 20 g/100 g was carried out to determine its influence on physico-chemical, rheological, nutritional and sensory characteristics of composite flour doughnuts. Commercial wheat variety, Inqlab-91 was found suitable for the preparation of doughnuts. Sensory and objective evaluations (weight, volume and specific volume) of doughnuts were carried out to evaluate the acceptability of doughnuts. Protein, lysine and trypsin inhibitor contents increased significantly (P<0.05) from 12.10 to 13.84 g/100 g, 2.46-3.58 g/100 g protein and 173 to 187 TIU/g on increasing the level of vetch flour from 0 to 15 g/100 g in the doughnuts, respectively. In vitro protein digestibility of doughnuts was also found to increase (71.8-76.3 g/100 g). It was inferred that doughnuts supplemented with vetch flour up to the level of 15 g/100 g were sensorily acceptable.     

Investigation of quality attributes of ice-stored Pacific white shrimp (Litopenaeus vannamei) as affected by sequential minimal ozone treatment

Ozone treatment is among non-thermal technologies with great promise to the seafood industry. Additionally, the demand for high quality minimally processed food products is increasing worldwide. However, no research endeavors has explored the quality attributes of sequential minimal ozone-treated ice stored shrimp. Therefore, the present investigation was undertaken to study the quality attributes of ice-stored Pacific white shrimp subject to minimal ozone treatment sequentially applied at days 1, 3, 5, 8 and 11. Quality indicators measured include aerobic plate count (APC), titratable acidity (TA), metric chroma, hue difference (ΔH), total colour difference (TCD), trimethylamine-nitrogen (TMA-N), total volatile basic-nitrogen (TVB-N), peroxide value (PV), p-anisidine value (AnV) and total oxidation (totox). The results indicated that the TA, metric chroma, ΔH, TCD, APC, TMA-N, TVB-N, PV, AnV and Totox values changed significantly with storage. Also, statistical differences in correlations and temporal rates of TMA-N and TVB-N as well as PV and AnV of sequential minimal ozone-treated ice-stored shrimp were obtained compared to control (P < 0.05). The noticeable reductions in APC, TMA-N, TVB-N and PV showed sequential minimal ozone treatment to resemble an anti-oxidant and thus, could within the respective limits of acceptability promise the safety of shrimp for consumption.