Search Results (6)
New approaches in calibration for multielement laser ablation inductively coupled plasma mass spectrometry analysis
One of commonly used analytical technique for direct elemental analysis of solid samples is Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Although widely used for the analysis of various samples, obtaining accurate quantitative results remains a major challenge as matrix-matched standards are required. The aim of this thesis was …
Temperature fractionation of mercury in the cement production process
Cement production is one of the main contributors to mercury emissions in to the atmosphere. Many national and international legal i nstruments aim to control and reduce Hg emissions. Hg enters the cement production process as an impurity in fuels and raw materials, with the latter being the main source …
Assessment of individual-level exposure to air pollutants using personal monitoring
A paradigm shift is occurring in the assessment of exposure to urban environmental stressors. Improved accuracy of personal monitors has enabled researchers to study exposure at the individual level. Monitoring stations are the primary reference point for air quality in urban environments, although there is a need to assess exposure …
Demand forecasting with machine learning methods
This thesis examines how machine learning can be applied in demand forecasting. In particular, it describes a novel approach toward lumpy and intermittent demand forecasting. It advocates using a two-fold model for forecasting lumpy (irregular demand occurrence, strong demand size variability) and intermittent (irregular demand occurrence, little demand size variability) …
Metrology of mercury measurements in the air
Atmospheric mercury (Hg) plays an important role in the biogeochemical Hg cycle. Hg species in the atmosphere are present in very low concentrations. While gaseous elemental mercury (GEM) is relatively inert, gaseous oxidized (GOM) and particulate-bound (PBM) mercury are highly reactive. These characteristics of atmospheric Hg species make the speciation …
Vacuum metrology and the role of surface conditions on the tangential momentum accommodation of molecules in a rarefied gas
The interactions between gas molecules and a surface strongly affect the behaviour of systems in a large array of research fields, such as vacuum science and metrology, microfluidics, particle physics, and nuclear physics. In this work, focus is given to the momentum accommodation of gas molecules. The parameter used in …