Experimental and analytical study on biodiesel and diesel spray characteristics under ultra-high injection pressure

In-vitro cell exposure studies for the assessment of nanoparticle toxicity in the lung - A dialog between aerosol science and biology

Engineered nanoparticles are becoming increasingly ubiquitous and their toxicological effects on human health, as well as on the ecosystem, have become a concern. Since initial contact with nanoparticles occurs at the epithelium in the lungs (or skin, or eyes), in vitro cell studies with nanoparticles require dose-controlled systems for delivery of nanoparticles to epithelial cells cultured at the air-liquid interface. A novel air-liquid interface cell exposure system (ALICE) for nanoparticles in liquids is presented and validated. The ALICE generates a dense cloud of droplets with a vibrating membrane nebulizer and utilizes combined cloud settling and single particle sedimentation for fast (~10 min; entire exposure), repeatable (<12%), low-stress and efficient delivery of nanoparticles, or dissolved substances, to cells cultured at the air-liquid interface. Validation with various types of nanoparticles (Au, ZnO and carbon black nanoparticles) and solutes (such as NaCl) showed that the ALICE provided spatially uniform deposition (<1.6% variability) and had no adverse effect on the viability of a widely used alveolar human epithelial-like cell line (A549). The cell deposited dose can be controlled with a quartz crystal microbalance (QCM) over a dynamic range of at least 0.02-200 μg/cm2. The cell-specific deposition efficiency is currently limited to 0.072 (7.2% for two commercially available 6-er transwell plates), but a deposition efficiency of up to 0.57 (57%) is possible for better cell coverage of the exposure chamber. Dose-response measurements with ZnO nanoparticles (0.3-8.5 μg/cm2) showed significant differences in mRNA expression of pro-inflammatory (IL-8) and oxidative stress (HO-1) markers when comparing submerged and air-liquid interface exposures. Both exposure methods showed no cellular response below 1 μg/cm2 ZnO, which indicates that ZnO nanoparticles are not toxic at occupationally allowed exposure levels. The ALICE is a useful tool for dose-controlled nanoparticle (or solute) exposure of cells at the air-liquid interface. Significant differences between cellular response after ZnO nanoparticle exposure under submerged and air-liquid interface conditions suggest that pharmaceutical and toxicological studies with inhaled (nano-)particles should be performed under the more realistic air-liquid interface, rather than submerged cell conditions.

/pdf/a-dose-controlled-system-for-air-liquid-interface-cell-3sbbuoim42.pdf

A dose-controlled system for air-liquid interface cell exposure and application to zinc oxide nanoparticles.

The use of hot electrons generated from the decay of surface plasmons is a novel concept that promises to increase the conversion yield in solar energy technologies. Titanium nitride (TiN) is an emerging plasmonic material that offers compatibility with complementary metal-oxide-semiconductor (CMOS) technology, corrosion resistance, as well as mechanical strength and durability, thus outperforming noble metals in terms of cost, mechanical, chemical, and thermal stability. Here, it is shown that plasmonic TiN can inject into TiO2 twice as many hot electrons as Au nanoparticles. TiO2 nanowires decorated with TiN nanoparticles show higher photocurrent enhancement than decorated with Au nanoparticles for photo-electrochemical water splitting. Experimental and theoretical evidence highlight the superior performance of TiN in hot carrier collection due to several factors. First, TiN nanoparticles provide broadband absorption efficiency over the wavelength range 500–1200 nm combined with high field enhancement due to its natural cubic morphology. Second, TiN forms an Ohmic junction with TiO2, thus enabling efficient electron collection compared to Au nanoparticles. Since TiN nanoparticles have strong plasmon resonances in the red, the entire solar spectrum is covered when complemented with Au nanocrystals. These findings show that transition metal nitrides enable plasmonic devices with enhanced performance for solar energy conversion.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adom.201601031

Broadband Hot Electron Collection for Solar Water Splitting with Plasmonic Titanium Nitride

Direct combustion of recyclable metal fuels for zero-carbon heat and power

CFD modeling of the in-cylinder flow in direct-injection Diesel engines

Development and validation of a theoretical model for diesel spray penetration

Computational Study of Heat Transfer to the Walls of a DI Diesel Engine

Computational study on the deposition of ultrafine particles from Diesel exhaust aerosol

We thank the European Commission for partially funding of this work through the Project "COMETNANO" (FP7-NMP4-SL-2009-229063).

A. Gil

Papers

CFD modeling of the in-cylinder flow in direct-injection Diesel engines

Development and validation of a theoretical model for diesel spray penetration

Computational Study of Heat Transfer to the Walls of a DI Diesel Engine

Computational study on the deposition of ultrafine particles from Diesel exhaust aerosol

Study of Basic Oxidation and Combustion Characteristics of Aluminum Nanoparticles under Enginelike Conditions