Transport in the static diffusion cloud chamber revisited

The static diffusion chamber (SDC) allows the measurement of critical supersaturation and of nucleation rates and it is a powerful instrument for the vapor nucleation study. Earlier, within the scope of the International Nucleation Workshop Group, nucleation rates of the n-pentanol–helium system have been measured using different experimental techniques. Disagreement of experimental data obtained using the static diffusion chamber and data obtained using other methods, particularly the laminar flow diffusion chamber, can be explained by re-examining the mass and energy transport analysis used to describe static diffusion chamber operation. In the present research we describe the mass and energy transport in the SDC modeled as an effectively open system with mass and energy transport in one direction with a nonzero diffusion flux at the system boundaries. Calculated values for vapor supersaturation are compared with the n-pentanol nucleation rate experimental results of the American–Czech group [M. Rudek, J. L. Katz, I. Y. Vidensky et al., J. Chem. Phys. 111, 3623 (1999)] and with a nucleation rate Reference Equation obtained from an earlier investigation involving the n-pentanol–helium system. From our results one can see that there is a significant difference in the calculated supersaturation for all of the data. The magnitude of this difference is quite large even for the relatively small vapor mass fractions at a nucleation temperature of 260 K. We also note that the calculated nucleation temperatures from our analysis are slightly larger than those reported in the work of Rudek et al.4 We performed our calculations with and without the thermal diffusion term. We observed that the effect of thermal diffusion on the transport process is relativelly small and is not particularly essential to include in this comparison that we are making the effects of the different flux boundary conditions

Raman spectra of single-walled carbon nanotubes synthesized by aerosol CVD-method using ferrocene and CuNi nanoparticles

Properties of single-walled carbon nanotubes (SWCNTs) obtained by aerosol method of chemical deposition from the gas phase using ethanol, ferrocene, and CuNi nanoparticles are studied. The structural and vibrational characteristics of synthesis products are determined by Raman spectroscopy. The influence of the catalyst nanoparticles introduced into the reaction mixture on the properties of the synthesized SWCNTs is discussed

Raman spectra of single-walled carbon nanotubes synthesized by aerosol CVD-method using ferrocene and CuNi nanoparticles

Properties of single-walled carbon nanotubes (SWCNTs) obtained by aerosol method of chemical deposition from the gas phase using ethanol, ferrocene, and CuNi nanoparticles are studied. The structural and vibrational characteristics of synthesis products are determined by Raman spectroscopy. The influence of the catalyst nanoparticles introduced into the reaction mixture on the properties of the synthesized SWCNTs is discussed

Conductivity of thin films based on single-walled carbon nanotubes grown by chemical vapor deposition

Electrical and optical properties of thin films of single-walled carbon nanotubes (SWCNT) obtained by aerosol chemical vapor deposition using ethanol, ferrocene, and sulfur are studied. Structural and geometrical characteristics of the synthesis products are determined by the methods of Raman spectroscopy and transmission electron microscopy. The effect of sulfur on the properties of the SWCNTs and thin films based on them is found

Fused filament fabricated polypropylene composite reinforced by aligned glass fibers

3D printing using fused composite filament fabrication technique (FFF) allows prototyping and manufacturing of durable, lightweight, and customizable parts on demand. Such composites demonstrate significantly improved printability, due to the reduction of shrinkage and warping, alongside the enhancement of strength and rigidity. In this work, we use polypropylene filament reinforced by short glass fibers to demonstrate the effect of fiber orientation on mechanical tensile properties of the 3D printed specimens. The influence of the printed layer thickness and raster angle on final fiber orientations was investigated using X-ray micro-computed tomography. The best ultimate tensile strength of 57.4 MPa and elasticity modulus of 5.5 GPa were obtained with a 90° raster angle, versus 30.4 MPa and 2.5 GPa for samples with a criss-cross 45°, 135° raster angle, with the thinnest printed layer thickness of 0.1 mm.Peer reviewe