Quantitative detection of species-specific DNA in feedstuffs and fish meals

A sensitive and rapid method for the quantitative detection of bovine-, ovine-, swine-, and chicken-specific mitochondrial DNA sequences based on real-time PCR has been developed. The specificity of the primers and probes for real-time PCR has been tested using DNA samples of other vertebrate species that may also be present in rendered products. The quantitative detection was performed with dual-labeled probes (TaqMan) using absolute quantification with external standards of single species meat-and-bone meals. This method facilitates the detection of 0.01% of the target species-derived material in concentrate feed mixtures and fish meals.     

Microfluidic switchboards with integrated inertial pumps

Arrays of H-shaped microfluidic channels connecting two different fluidic reservoirs have been built with silicon/SU8 microfabrication technologies utilized in production of thermal inkjet printheads. The fluids are delivered to the channels via slots etched through the silicon wafer. Every H-shaped channel comprises four thermal inkjet resistors, one in each of the four legs. The resistors vaporize water and generate drive bubbles that pump the fluids from the bulk reservoirs into and out of the channels. By varying relative frequencies of the four pumps, input fluids can be routed to any part of the network in any proportion. Several fluidic operations including dilution, mixing, dynamic valving, and routing have been demonstrated. Thus, a fully integrated microfluidic switchboard that does not require external sources of mechanical power has been achieved. A matrix formalism to describe flow in complex switchboards has been developed and tested.     

Self-assembled silver nanoislands formed on glass surface via out-diffusion for multiple usages in SERS applications

We demonstrate that silver nanoisland film self-assembled on the surface of silver-containing glass in the course of thermal processing in hydrogen is capable to detect 10⁻⁷ M concentration of rhodamine 6G in water using surface enhanced Raman spectroscopy (SERS) technique. The film can be multiply restored on the same glass substrate via annealing of the glass in hydrogen. We showed that the film can be self-assembled after as much as ten circles of the substrate cleaning followed by annealing. The proposed technique of the silver nanoisland film formation enables multiple usage of the same glass substrate in SERS experiments.     

Controllable Generation of a Submillimeter Single Bubble in Molten Metal Using a Low-Pressure Macrosized Cavity

Metallurgical and Materials Transactions B - We develop a method for generation of a single gas bubble in a pool of molten metal. The method can be useful for applications and research studies...     

Effect of ternary solute interaction on interfacial segregation and grain boundary embrittlement

Effect of ternary solute interaction on interfacial segregation and grain boundary embrittlement in an M–I–J system is modeled on the basis of combined Guttmann and Rice–Wang approaches. It is clearly shown that repulsive I–J interaction strengthens interfacial segregation of the impurity I, suppresses segregation of the solute J, and substantially enhances intergranular embrittlement. Attractive interaction exhibits an opposite effect. Generally, the effect of the ternary interaction is weaker than that of the binary one. Although there are only rare experimental data in this respect, their comparison to model calculations shows a very good agreement.