Abstract: A method for determining airborne concentrations of an ensemble of particulate matter below the size fraction 2.5 ?m in aerodynamic diameter (PM2.5). The method is to be composed of a sharp cut PM2.5 cyclone, optical sensor capable of producing scattering coefficients dependent on particle size, temperature and humidity sensors for adapting to changes in the environment, and a processing system for applying logic-based algorithm to convert raw sensor values into PM concentrations. The optical sensor is a dual wavelength integrating nephelometer capable of yielding particle characteristic scattering coefficients at two wavelengths. The particle scattering ratios between two wavelengths are used in conjunction with temperature and humidity in the method's algorithm to reduce particle growth bias and to ultimately yield PM2.5 concentrations.

Abstract: A method for determining airborne concentrations of an ensemble of particulate matter below the size fraction 2.5 ?m in aerodynamic diameter (PM2.5). The method is to be composed of a sharp cut PM2.5 cyclone, optical sensor capable of producing scattering coefficients dependent on particle size, temperature and humidity sensors for adapting to changes in the environment, and a processing system for applying logic-based algorithm to convert raw sensor values into PM concentrations. The optical sensor is a dual wavelength integrating nephelometer capable of yielding particle characteristic scattering coefficients at two wavelengths. The particle scattering ratios between two wavelengths are used in conjunction with temperature and humidity in the method's algorithm to reduce particle growth bias and to ultimately yield PM2.5 concentrations.

Abstract: A battery module includes a plurality of cells arranged in a battery pack. The battery pack includes a first tray configured to receive a first row of cells and a second row of cells. A second tray is provided over the first tray, the first row of cells, and the second row of cells. The second tray is configured to receive a third row of cells and a fourth row of cells. A third tray is provided over the second tray, the third row of cells, and the fourth row of cells. The first row of cells and the second row of cells are arranged between the first tray and the second tray and the third row of cells and the fourth row of cells are arranged between the second tray and third tray.