Microtexture Analysis and Modeling of Ambient Fatigue and Creep-Fatigue Damages in Ti-6Al-4V Alloy

In the present investigation, microtexture analysis using electron back-scattered diffraction technique has been performed to study fatigue- and creep-fatigue damages and associated deformation structures in Ti-6Al-4V alloy. Special emphasis has been given to low-angle grain boundary configuration and its possible application as a damage indicator. Damage is mostly present in the form of voids as investigated through scanning electron microscopy. Stored deformation energies have been evaluated for the strain-controlled fatigue-, the stress-controlled fatigue-, and the creep-fatigue-tested samples. Stored deformation energies have also been analyzed vis-à-vis total damage energies to quantify the contribution of damages to various samples. A relation between the stored deformation energy and the applied strain amplitude has been proposed in this study.     

Metabolisable energy values for growing chicks of some feedstuffs from Sri Lanka

Seven chick bioassays were conducted with 600 one-week-old White Leghorn cockerels to determine the zero nitrogen-corrected metabolisable energy (ME_n) values of twenty-three Sri Lankan-produced feedstuffs. The ME_n values (MJ kg^?1 dry matter) of the feedstuffs were: maize 14.28, sorghum 14.42, broken rice 12.35, rough rice 9.21, rice bran grade I 14.28, rice bran grade II 9.30, wheat feed flour 9.31, wheat bran 7.66, undetoxified cassava root meal 13.38, detoxified cassava root meal 15.92, coconut oil meal 7.46, sesame oil meal 11.48, rubber seed meal 11.25, kapok seed meal 8.75, urd bean 12.68, cassava leaf meal 7.82, local fish meal 11.97, skim milk powder 10.41, meat and bone meal 8.02, sugar filter-press mud 8.85, cocoa husk meal 7.46, Mango seed kernel meal 10.84, and tea refuse 6.02. The difference between the ME_n values of undetoxified and detoxified cassava root meal indicate that hydrocyanic acid interferes with energy utilisation in poultry.     

Microvoids in organic coatings

Organic coatings in which air bubbles (of micron size) are introduced for producing opacity due to light scattering are called microvoid coatings. A historical account of the development of this type of coatings, various formulation techniques and their assessment, properties of microvoid coatings and their uses are reviewed. Some of the properties which have advantages over the conventional organic coatings, such as hiding power, open and closed cellular void structure and density of microvoid coatings are highlighted and the uses of microvoid coatings in fields other than surface coatings are also described.     

Progress of Research in Cashew Industry

Cashewnut shell liquid and its distillation products cardanol and CNSL-residue have become very important raw materials because of their versatile uses in surface coatings, plastics, rubber, synthetic chemicals and drugs, synthetic wood and other fields. The multisided applications of CNSL are due to the presence of the phenolic group in its structure, combined with an unsaturated long side chain. Research work is being conducted in various countries on this naturally occurring raw material since the middle of the 19th century. An attempt is made herein to review the progress of research work conducted till to-day on these products.     

A Simple Technique to Improve the Firmness of Cooked Potato Tissue

Potato tissue samples with varying cell turgor pressures were prepared by soaking in mannitol solutions (0 to 0·5 M ). Increased concentration of mannitol in the soaking solutions decreased the cell turgor pressure in potato tissues providing samples with varying degrees of turgidity or plasmolysis. Firmness changes in potato tissues of differing turgor pressure during cooking were examined using a Zwick universal testing machine and also by chewing tests. A modified device attached to a Zwick machine facilitated complete immersion of a potato disc in circulating boiling water, providing rapid and reproducible heat transfer in the tissue during firmness measurements. Tissue firmness expressed as the force required to cause 10% strain in the sample varied in potato discs treated with differing mannitol solutions. Potato discs soaked in 0 to 0·3 M mannitol solutions were more turgid at 20°C than other samples and showed higher tissue firmness. However, when discs of potato were heated in the range of 20–90°C, samples treated with 0·4 and 0·5 M mannitol solutions showed some increase in tissue firmness while all other samples exhibited a rapid decline. Bite-force measurements on potato discs also indicated a rapid loss of tissue firmness in turgid samples. Potato tissues when cooked after soaking in 0·4 or 0·5 M mannitol solution showed more intact and inflated cells than other samples. © 1997 SCI     

Inorganic nanotubes reinforced polyvinylidene fluoride composites as low-cost electromagnetic interference shielding materials

Novel polymer nanocomposites comprising of MnO₂ nanotubes (MNTs), functionalized multiwalled carbon nanotubes (f-MWCNTs), and polyvinylidene fluoride (PVDF) were synthesized. Homogeneous distribution of f-MWCNTs and MNTs in PVDF matrix were confirmed by field emission scanning electron microscopy. Electrical conductivity measurements were performed on these polymer composites using four probe technique. The addition of 2 wt.% of MNTs (2 wt.%, f-MWCNTs) to PVDF matrix results in an increase in the electrical conductivity from 10^-16S/m to 4.5 × 10^-5S/m (3.2 × 10^-1S/m). Electromagnetic interference shielding effectiveness (EMI SE) was measured with vector network analyzer using waveguide sample holder in X-band frequency range. EMI SE of approximately 20 dB has been obtained with the addition of 5 wt.% MNTs-1 wt.% f-MWCNTs to PVDF in comparison with EMI SE of approximately 18 dB for 7 wt.% of f-MWCNTs indicating the potential use of the present MNT/f-MWCNT/PVDF composite as low-cost EMI shielding materials in X-band region.     

Lower bounds for dilation,wirelength, and edge congestion of embedding graphs into hypercubes

The Journal of Supercomputing - Interconnection networks provide an effective mechanism for exchanging data between processors in a parallel computing system. One of the most efficient...     

Jet flow characteristics of sinusoidal wavy nozzles

The flow characteristics of jets issued from a sinusoidal nozzle with in-phase and 180° out-of-phase exit configurations were investigated using PIV (particle image velocimetry) and flow visualization techniques. The experiments were carried out at a Reynolds number of about 6300 based on the mean width of the jet nozzle. Compared to a normal rectangular jet, the sinusoidal nozzle jets have smaller velocity deficits as the flow goes downstream. In addition, the turbulence intensity is suppressed in the horizontal center plane. For the case of in-phase wavy nozzle jet, the length of the potential core exhibits small variations along the lateral direction, while the 180° out-of-phase wavy nozzle jet shows large lateral variation in the length of potential core. The turbulent kinetic energy of the 180° out-ofphase nozzle jet also shows sinusoidal variation in the horizontal planes. Large-scale vortices shed from the sinusoidal edge of the nozzle interact strongly and migrate toward the center plane as the flow develops downstream.