The effectiveness factor is widely used to account for the interaction between pore diffusion and reactions on pore walls in porous catalytic pellets and solid fuel particles. The effectiveness factor is defined as the ratio of the reaction rate actually observed to the reaction rate calculated if the surface reactant concentration persisted throughout the interior of the particle, i.e., no rea...

A number of enzyme digestion assays show apparent first-order kinetics of reactant depletion. There are four possible explanations of this phenomenon: (i) the reaction is dominated by a first-order limiting step, (ii) the digestion follows a pseudo-first-order kinetics under the excess of a reactant species, (iii) the first-order kinetics is only applicable to the slow transient of the reaction...

Uniform dumbbell-like ZnO microcrystals had been successfully fabricated on a large scale via a facile solution technique under mild conditions. Obtained ZnO, with length of 1.2 to 1.6 μm and diameters of 350 to 600 nm, exhibited well-defined dumbbell-like morphology and hexagonal wurtzite structure and grew along the [001] direction. Effects of the reactant concentration on the sizes and morph...

microbial calcium carbonate, by bridging sand particles, can play an important role in sand dune stability. a study was carried out on the cementation of sand grains and infilling of pore spaces by caco3. two bacterial species (sporosarcina pasteurii and sporosarcina ureae), three reactant concentrations (0.5, 1 and 1.5m), and six reaction times (12, 24, 48, 96, 192 and 288 hours) were tested i...

This work describes a technology for performing and monitoring simultaneously several reactions confined in strings of microdroplets having identical volumes but different composition, and travelling with the same speed in parallel channels of a microfluidic device. This technology, called parallel microdroplets technology (PmicroD), uses an inverted optical microscope and a charge-coupled devi...

Real-time polymerase chain reaction (PCR) is one of the most sensitive and accurate methods for quantifying transcript levels especially for those expressed at low abundance. The selective amplification of target DNA over multiple cycles allows its initial concentration to be determined. The amplification rate is a complex interplay of the operating conditions, initial reactant concentrations, ...

Electrosynthesis has much to offer to the synthetic organic chemist. But in order to be widely accepted as a routine procedure in an organic synthesis laboratory, electrosynthesis needs to be presented in a much more user-friendly way. The literature is largely based on electrolysis in a glass beaker or H-cells that often give poor performance for synthesis with a very slow rate of conversion a...

Thermal explosions are often influenced by the complex interaction between transport and reaction phenomena. In particular, reactant consumption can promote safer, non-explosive operation conditions of combustion systems. However, in liquids or gases, the presence of forced convection can affect the behaviour of a system, instigating oscillations in the temperature, reactant concentration and v...