Soil is commonly composed of particles of different sizes, and soil particle size may greatly affect the growth of plants because it affects soil physical and chemical properties. However, no study has tested the effects of soil particle heterogeneity on the growth of clonal plants. We conducted a greenhouse experiment in which individual ramets of the wetland plant Bolboschoenus planiculmis we...

We present measurements of the growth of long columnar ice crystals from water vapor over a broad range of temperatures and supersaturation levels in air. Starting with thin, caxis ice needle crystals, we observed their subsequent growth behavior in a vapor diffusion chamber, extracting the initial radial growth velocities of the needles under controlled conditions. Approximating the hexagonal ...

A theory is developed of concurrent growth and coarsening of a dispersion of spheres that accounts for the exchange of heat by diffusion among the spheres due to their curvature differences and between the spheres and the environment due to an externally imposed heat extraction rate. The results show that in concurrent growth and coarsening the average particle radius asymptotically increases w...

Conformal mapping models are used to study the competition of noise and anisotropy in Laplacian growth. For this purpose, a family of models is introduced with the noise level and directional anisotropy controlled independently. Fractalization is observed in both anisotropic growth and growth with varying noise. The fractal dimension is determined from the cluster size scaling with cluster area...

We introduce a Monte Carlo model of nonlinear diffusive shock acceleration allowing for the generation of large-amplitude magnetic turbulence, i.e., ∆B ≫ B0, where B0 is the ambient magnetic field. The model is the first to include strong wave generation, efficient particle acceleration to relativistic energies in nonrelativistic shocks, and thermal particle injection in an internally self-cons...

New particle formation and growth events have been observed in several urban areas and are of concern due to their potential negative effects on human health. The main purpose of this study was to investigate the chemistry of ultrafine particles during the growth phase of the frequently observed nucleation events in Pittsburgh (approximately 100 events per year) and therefore infer the mechanis...

We measured air ion size distributions with an air ion spectrometer in the size range of 0.34–40.3 nm both indoors (in July) and outdoors (in August) in Helsinki, Finland in 2004. At the same time we measured particle number concentrations and size distributions with two condensation particle counters (indoors) and differential mobility particle sizer (outdoors). Our main focus was to study new...

The delivery of therapeutic proteins has gained momentum with development of biotechnology. However, large molecular weight, hydrophilic nature and susceptibility to harsh environment of gastrointestinal tract (GIT) resulted in low absorption. The main objective of this work was the design of a particulate system for oral delivery of recombinant human growth hormone (rhGH) on the basis of parti...

Atmospheric new particle formation (NPF) is a key source of ambient ultrafine particles that may contribute substantially to the global production of cloud condensation nuclei (CCN). While NPF is driven by atmospheric nucleation, its impact on CCN concentration depends strongly on atmospheric growth mechanisms since the growth rate must exceed the loss rate due to scavenging in order for the pa...

The applications of supported metal catalysts vary widely, from selective hydrogenation in the fine chemicals industry to the control of vehicle emissions. Yet many basic questions about the structure, activity, and durability of these catalysts remain unanswered. For example, there is still much uncertainty about the mechanism of metal particle growth, or sintering, which is a major cause of c...