The fractal nature of hydrodynamic features during nucleate boiling is illustrated in this study. Earlier reports in the literature explored the fractal nature of the thermal features in pool boiling. In these studies typically the time-delay technique was used to obtain chaos quantifiers in boiling from wall temperature fluctuation measurements. In this study experiments were performed at diff...

By performing near-critical fluid experiments in the weightlessness of an orbiting space vehicle, we have suppressed buoyancy-driven flows and gravitational constraints on the liquid-gas interface of a large gas bubble. At equilibrium, the liquid completely wets the walls of a cylindrical cell, and the bubble is pushed to the sidewall. In these experiments the system's temperature T is increase...

The production of machine parts usually ends with some kind of a heat treatment. A proper heat treatment, like quenching, provides increased surface hardness, which improves wear resistance. The quenching process must be fast to achieve the required hardness, but not too fast to prevent surface damage. Monitoring of the quenching process in real time, and an appropriate control can improve the ...

Forced convection boiling in microchannels is studied experimentally under the uniform heat flux boundary condition. Several microchannel heat sinks with integrated temperature sensors, spanning two orders of magnitude in height 5–500 μm, have been fabricated with designed nucleation sites on the bottom surfaces. The microchannels are capped by a glass wafer to monitor bubble activity using vid...

Owing to their high intrinsic thermal conductivity, carbon nanotubes (CNTs) have previously been incorporated into a variety of thermal management applications to improve cooling performance. Implementation of controlled CNT growth techniques and functionalization methods are applied herein to enhance boiling heat transfer from the porous capillary wicking surfaces widely used in high heat flux...

Pool boiling experiments are generally conducted with electrically heated surfaces in laboratories to obtain the heat transfer coefficient data. In many process applications however, a fluid stream is employed as the heating medium. The heat transfer data generated with the electrically heated test sections therefore raises the question of their applicability to practical equipment design. Simi...

The importance of liquid viscosity in chemical process design makes it one of the most measured transport properties. Nevertheless, of the 1893 compounds in the DIPPR 801 pure-component database, liquid viscosity and its temperature dependence (at 1 atm, or 0.1 MPa) have been predicted for nearly 50% of the compounds because no experimental data are available. Unfortunately, prediction methods ...

A ligand free, copper-catalyzed N-arylation reaction of amines with diheteroaryl halides in heterogeneous medium at room temperature has been developed. The protocol is very effective for low boiling amines and useful for amines available in aqueous solution. The reaction gives chemospecific arylation of amines with diheteroaryl halides in the mixture monoheteroaryl halides, diheteroaryl halide...

The present paper is an experimental investigation of roughness effects on nucleate pool boiling of refrigerant R113 on horizontal circular copper surfaces. The copper samples were treated by different sand paper grit sizes to achieve different surface roughness. The average surface roughness of the four samples was 0.901, 0.735, 0.65, and 0.09, respectively. The experiments were performed in t...

Background. Phenolic acids were repeatedly pointed out as powerful antioxidants. The studies in the past prove the differences in the phenolic acids content in malts and worts. In this work, the influence of wort boiling and whirlpool separation on the phenolic acid content was studied. Material and methods. Worts were produced in the local brewery by the infusion method using pale pilsner-type...