Climate models show that particles formed by nucleation can affect cloud cover and, therefore, the earth's radiation budget. Measurements worldwide show that nucleation rates in the atmospheric boundary layer are positively correlated with concentrations of sulfuric acid vapor. However, current nucleation theories do not correctly predict either the observed nucleation rates or their functional...

The results of a field investigation, vapor extraction tests, and long-term monitoring at a PCE-contaminated site in Saga, Japan, are reported. The field investigation indicated that PCE likely was trapped in a surface clayey sand layer (vadose zone), and soil vapor extraction (SVE) was adopted as the remediation approach. The field test results the effectiveness of SVE in removing volatile org...

Using a previously shown method, we prepared 2”-GaN wafers as templates for a self separation process. Self separation is happening during cooldown after growing thick layers of GaN in our hydride vapor phase epitaxy (HVPE) reactor. Our templates consist of GaN grown by metalorganic vapor phase epitaxy (MOVPE) directly on sapphire. These GaN layers are masked with 200nm of SiN that are structur...

The carbon nanostructure composed of an array of vertically aligned carbon nanotubes (CNTs) and a planar graphite layer (PGL) located at the top of the array has been obtained by the injection chemical vapor deposition method, realized using high temperature catalytic pyrolysis of xylene-ferrocene mixture. The carbon nature of the planar layer was identified using Auger electron spectroscopy. S...

The physical properties of HfO2 and Hf-silicate layers grown by the atomic layer chemical vapor deposition are characterized as a function of the Hf concentration and the annealing temperature. The peaks of Fourier transform infrared spectra at 960, 900, and 820 cm−1 originate from Hf–O–Si chemical bonds, revealing that a Hf-silicate interfacial layer began to form at the HfO2/SiO2 interface af...

The concept of co-catalytic layer structures for controlled laser-induced chemical vapor deposition of carbon nanotubes is established, in which a thin Ta support layer chemically aids the initial Fe catalyst reduction. This enables a significant reduction in laser power, preventing detrimental positive optical feedback and allowing improved growth control. Systematic study of experimental para...

This study examines both high-flux flow boiling and critical heat flux (CHF) under highly subcooled conditions using FC-72 as working fluid. Experiments were performed in a horizontal flow channel that was heated along its bottom wall. High-speed video imaging and photomicrographic techniques were used to capture interfacial features and reveal the sequence of events leading to CHF. At about 80...

The dynamics of single vapor bubbles in FC-72 generated by a transient heat pulse applied to a square 260 · 260 lm microheater are investigated for different heat fluxes between 3 and 44 MW/m. It is found that in all cases the growth consists of two steps, a first relatively violent one, followed by a shrinking of the vapor mass and a subsequent slower expansion. At the higher heat fluxes, the ...

Heterogeneous nucleation of a liquid droplet on a solid surface was simulated with the molecular dynamics method. Argon vapor was represented by 5,760 Lennard-Jones molecules and the solid surface was represented by one layer of 4,464 harmonic molecules with the constant temperature heat bath model using the phantom molecules. The potential parameter between a solid molecule and a vapor molecul...

Liquid droplets of water and argon surrounded by their vapor have been simulated by the molecular dynamics method. To explore the surface phenomena of clusters, each molecule is classified into 'liquid', 'surface', or 'vapor' with respect to the number of neighbor molecules. The contribution of a 'surface' molecule of the water cluster to the far infrared spectrum is almost the same as that of ...