A silicon micromachining method that is able to create deep silicon dioxide blocks at selected locations in a silicon substrate is presented. The process combines deep-reactive-ion etching (DRIE), thermal oxidation, deposition of silicon dioxide and optional planarization. Design issues and parameters for the creation of such blocks are discussed. The selectively defined silicon dioxide blocks ...

The application of nanotechnology to medicine constitutes a major field of research nowadays. In particular, the use of mesoporous silica and carbon nanoparticles has attracted the attention of numerous researchers due to their unique properties, especially when applied to cancer treatment. Many strategies based on stimuli-responsive nanocarriers have been developed to control the drug release ...

In this paper we investigate the use of active coated nanoparticles (CNPs) for nano-sensing applications. Simulation results of the optical properties of an active CNP with a 24nm radius active silica core and 6nm thick plasmonic shell made of silver that has been functionalized by an additional spherical outer layer of varying thickness and refractive index are presented. In particular, the ef...

This study compared respirable dust and nanoparticle concentrations measured by different sampling devices at a titanium dioxide pigment factory. Respirable particle mass concentrations, nanoparticle concentrations, particle size distribution and particle metallic content were measured at different sampling locations. The sampling results of the Multi-orifice Uniform Deposit Impactor (MOUDI) sh...

background: agate is a hard silica stone with bands of various colors, which is used in jewelry. the agate grinding workers are exposed to silica dust. objective: to determine the prevalence of respiratory diseases in agate grinding workers and the associated factors. methods: in this cross-sectional study, 170 agate grinding workers from mashhad, northeastern iran, were examined. medical and o...

Understanding the delivered cellular dose of nanoparticles is imperative in nanomedicine and nanosafety, yet is known to be extremely complex because of multiple interactions between nanoparticles, their environment, and the cells. Here, we use 3-D reconstruction of agglomerates preserved by cryogenic snapshot sampling and imaged by electron microscopy to quantify the "bioavailable dose" that i...

Porous Carbon Nanoparticles (PCNs) with well-developed microporosity were obtained from bio-waste oil palm leaves (OPL) using single step pyrolysis in nitrogen atmosphere at 500-600 °C in tube-furnace without any catalysis support. The key approach was using silica (SiO2) bodies of OPL as a template in the synthesis of microporous carbon nanoparticles with very small particle sizes of 35-85 nm ...

A nitride spacer with an underlying deposited tetraethoxysilane oxide, that behaves as a convenient etch stop layer, is a popular choice for sidewall spacer in modern complementary metal–oxide– semiconductor process flows. In this work we have investigated the effect of the silicon nitride spacer process on the boron profile in silicon and the related dose loss of B from the Si into the silicon...

Cerium dioxide (CeO2) and silicon dioxide (SiO2) nanoparticles are of widespread use in modern life. This means that human beings are markedly exposed to them in their everyday life. Once passing biological barriers, these nanoparticles are expected to interact with endothelial cells, leading to systemic alterations with distinct influences on human health. In the present study we observed the ...

background and aim: this study investigated the reinforcing effect of silica nanoparticles when incorporated into the matrix phase of an experimental dental fiber reinforced composites (frc) through the evaluation of the flexural properties of the composites. materials and methods: in this experimental study frc samples were divided into two main groups (containing two or three bundles) either ...