Viscosity of Fe90B x Si(10 − x) melts

High Temperature - The temperature dependences of the viscosity of liquid Fe90B x Si(10 − x) alloys are studied in the mode of heating and subsequent cooling. The temperature dependences of...     

MULTI-WALL CARBON NANOTUBE-BASED DNA NANOSENSOR FOR DETERMINING MITOXANTRONE-DNA INTERACTION IN-VITRO

The present study involves the development of a carbon nanotube based DNA nanosensor to determine the toxicological behavior of mitoxantrone (MTX). Mitoxantrone intercalates with DNA and produces a MTX-DNA adduct, resulting in the blockade of protein synthesis and excessive production of free radicals in the myocardium which eventually leads to cardiac toxicity. So, our work employs a DNA nanosensor to investigate the interaction of MTX with DNA. Multi-wall carbon nanotubes (MWCNTs) were functionalized with carboxyl group and were used for immobilization of DNA to construct the DNA nanosensor. The DNA nanosensor was immersed in MTX solution to monitor MTX-DNA interaction with respect to time and alter the resistance of the nanosensor. It was observed that MTX-DNA interaction is fast initially and as time elapses, the change in interaction gets slow due to formation of MTX-DNA adduct. The limit of detection (LOD) and limit of quantification (LOQ) were found as 150 (ng/mL) and 456 (ng/mL), respectively, for DNA nanosensor. This study suggests that the potentiometric nanosensor allows real-time monitoring of the drug-DNA interaction changes by measuring the potential at DNA/sensor interface which can prove to be an important tool in drug discovery pipelines and molecular toxicology.     

Viscosity and supercooling of Fe-Cr (≤40 at % Cr) melts

We have studied the composition dependences of the kinematic viscosity (ν) and supercooling (Δt) of Fe-Cr melts at chromium contents of up to 40 at %. The results indicate that there is a minimum in viscosity at 5 at % Cr, a maximum at 12 at % Cr, and a sharp rise in the crystallization tendency of the solid solution in this composition range. The Δt(x) and ν(x) data obtained can be understood in terms of the composition dependence of the bonding energy, which is governed by the geometric and chemical short-range order in the atomic arrangement. Using a probabilistic approach to evaluation of various short-range order configurations and the experimental viscosity and supercooling data at chromium contents of 2.5 and 30 at %, we have calculated Δt(x) and ν(x) up to 40 at % Cr.     

Effects of the geometric orientations of the nozzle exit on the breakup of free liquid jet

Free liquid jets are produced through various geometric orientations of the nozzle exit. The breakup lengths of liquid jets under various geometric orientations of the nozzle exit were studied. Images of jets were captured using a high-speed camera with a maximum frame rate of 1000 frames per second and were analyzed to determine the dynamics between jets and breakup lengths. The breakup length of jets changes with the cut angle of the nozzle exit. In addition, adding polymer reduces the effect of the cut angle of the nozzle exit on the breakup length for an entire range of velocities. The effect of the cut angle on breakup length is predominant for aqueous solutions with surfactants. This work provides motivation for further computational research to study jet dynamics in a partially covered nozzle exit, such as the case in which the boundary conditions near the nozzle opening is more complex with the cut angle and its vertex position, which directly reflects liquid jet dynamics.     

Improving Performance of the Synthesis of Silica Nanoparticles by Surfactant-incorporated Wet Attrition Milling

Silicon - Abundant applications of silica nanoparticles (SiNPs) have motivated many research groups for silica nanoparticles synthesis with tuned properties. Here we show the formation of SiNPs...     

Recyclable Amberlyst-70 as a Catalyst for Biginelli Reaction: An Efficient One-Pot Green Protocol for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones

An environmentally benign aqueous protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using Amberlyst-70 as a recyclable catalyst has been developed. The use of resinous, nontoxic, thermally stable and inexpensive Amberlyst-70, as a recyclable heterogeneous catalyst, makes the process simple with negligible chemical waste. Thus renders this method an environmentally acceptable synthetic tool for Biginelli reaction.     

Structural model of the Ni2B amorphous alloy from the data of molecular dynamics simulation

The structure of the Ni₂B amorphous alloy has been investigated by the molecular dynamics method using the Heine-Abarenkov-Animalu and Animalu potentials. The amorphous state is reached by melting a microcrystal of the appropriate composition with subsequent cooling of the melt. The interatomic distances Ni-Ni, B-B, and Ni-B and the boron coordination numbers with respect to boron and nickel are determined from the calculated partial radial atomic distribution functions (RDFs). It is found that, upon transition from the crystalline state to the amorphous state, the antiprismatic-type structure transforms into the trigonalprismatic structure.     

Energy Conversion Efficiency of an Exponentially Graded Thermoelectric Material

This work describes an analytical model that predicts the effects of property gradients on the energy conversion efficiency of a functionally graded thermoelectric material (FGTEM) with an exponentially varying Seebeck coefficient S, electrical resistivity ρ, and thermal conductivity k. The figure-of-merit parameter, Z = S ²/(ρk), thus also varies exponentially. A closed-form solution for the temperature distribution in the FGTEM and the efficiency as a function of current density are obtained. The peak efficiency and the optimal current density are determined from the efficiency solution. It is found that the efficiency may be increased by about 30% using appropriate property gradients.