Electrothermal atomic absorption spectrometry has five major advantages for measurements of trace metals in biological materials, in comparison to measure­ ments by conventional flame atomic absorption analysis: (1) Trace metal contami­ nation is minimized by avoidance of preliminary chemical extractions and addi­ tions of reagents; (2) Sample volumes are small (1 to 50 /*1). The entire sample ...

Lithium and copper are distributed equally between cells and serum. However, red cells contain more magnesium, zinc, and iron than does serum. To assure analytical accuracy, hemolysis should be avoided. Also, cells and sera must be separated shortly after sample collection. Since aqueous solutions leach magnesium from glass containers, materials and reagents meant for magnesium analysis should ...

Flashing or thermodynamic breakup of a liquid jet occurs when a pressurized subcooled or saturated liquid is released to a lower pressure, resulting in violent vapor nucleation, expansion, and break up of the liquid phase. Flashing is known to produce very fine droplet atomization, often not possible by traditional mechanical means. In this work, flashing atomization is introduced in a spray bu...

Title of Document: SPRAY FLAME AND EXHAUST JET CHARACTERISTICS OF A PRESSURIZED SWIRL COMBUSTOR Martin Brendan Linck, Doctor of Philosophy, 2006 Directed By: Professor Ashwani K. Gupta Department of Mechanical Engineering This work describes an investigation of swirl-stabilized flames, created in a combustor featuring co-annular swirling airflows, under unenclosed, enclosed, and submerged condi...

The atomic absorption of aluminum with air-acetylene flame was interfered by the formation of involatile compounds in the flame. Amines promoted the atomization of aluminum in the flame. Aluminum could be determined by atomic absorption spectrometry with an air-acetylene flame. The absorption of aluminum increased and then attained a constant value as the concentration of amines increased. The ...

This article describes the concept of controlling and correcting interference resulting from flame instability and sample reduction in absorption atomic spectrometry with flame atomization. Using popular laboratory spectrometers, which enable simultaneous or fast sequential measurements of many elements in the course of a single analysis, methods of controlling and correcting problems with inst...

A new combustion model is developed and applied to simulate combustion in dual-fuel engines in which the premixed natural gas is ignited by the combustion flame initiated by a diesel spray. The model consists of a diesel auto-ignition model and a flame propagation model. A G-equation model previously developed to simulate SI engine combustion was incorporated with an auto-ignition model to simu...

Understanding the combustion characteristics of fuel droplets laden with energetic nanoparticles (NP) is pivotal for lowering ignition delay, reducing pollutant emissions and increasing the combustion efficiency in next generation combustors. In this study, first we elucidate the feedback coupling between two key interacting mechanisms, namely, secondary atomization and particle agglomeration; ...

Large-eddy simulation (LES) of kerosene spray combustion in a model supersonic combustor with cavity flame holder is carried out. Kerosene is injected through the ceiling of the cavity. The subgrid-scale (SGS) turbulence stress tensor is closed via the Smagorinsky’s eddyviscosity model, chemical source terms are modelled by a finite rate chemistry (FRC) model, and a four-step reduced kerosene c...

A study of the ignition of non-fire-resistant hydraulic fluid sprays was conducted by the National Institute for Occupational Safety and Health. Both an open flame and a hot steel surface were used as the external heat sources. With the open flame as the heat source, the minimum oil temperature and minimum spray nozzle pressure that resulted in an ignition were measured. The effects of the dist...