At the end of the course, the students will: -Understand the effects of airborne particulate on outdoor and indoor air quality and the basics of aerosol behavior, including diffusion and charging. -Gain fundamental knowledge of the laws governing aerosols' mechanical, optical, and electrical properties. -Learn about state-of-the-art instruments for airborne particles from micrometer to nanometer size range. -Understand basic principles to generate, sample, measure, and control airborne particles. -Learn how to measure and interpret experimental data using particle size statistics. -Learn how to model indoor particulate matter concentration and its control. -Develop soft skills related to project report preparation and presentation.

Basic concepts of Mathematics, Chemistry, and Physics as obtained in the bachelor's degree program. Mandatory precedence of Fluid Mechanics, Thermodynamics, and Heat Transfer courses. Basic IT applications: text editor, calculation spreadsheet, and presentation tools.

Aerosol technology applications and basic definitions. Particulate matter health effects on humans. Air quality standards for outdoor air. Indoor air quality. Categories of airborne contaminants. Particle properties and characterization. Equivalent sphere concept. Properties of gases. Kinetics theory of gases. Mean free path and Knudsen number. Particle Reynolds number. Mechanics of aerosol particles. Newton's and Stokes’s laws: terminal settling velocity, slip correction, and aerodynamic diameter. Straight-line particle acceleration and curvilinear particle motion. Stokes number. Single and multiple impactors. Instruments measuring aerodynamic particle size. Particle size statistics. Probability density and cumulative distribution functions. Moments of a distribution and physical meaning for particle distributions. Lognormal frequency function and its properties. Conversion of parameters from one moment distribution to another. Adhesion of aerosol particles to surfaces. London-van der Waals and electrostatic forces. Surface tension of adsorbed liquid films. Detachment of particles. Resuspension. Particle reentrainment and bounce. Brownian motion and diffusion. Stokes-Einstein equation. Diffusion coefficient of an aerosol particle. Deposition by diffusion. Rate of particle deposition on surfaces: laminar and turbulent regimes. Diffusion batteries. Air filtration. Air filter elements, media, and systems. Deep and surface filtration. Layer efficiency in fibrous filtration. Most penetrating particle size. Airflow resistance and quality factor of an air filter element. Deposition mechanisms: interception, inertial impaction, diffusion, gravitational settling, electrostatic attraction. Performance measurement and rating of air filters. Size range of a typical atmospheric aerosol and most common "loading" dusts. Surface and depth loading. PM-based approach for air filter classification system with ePMx rating. Strategies for controlling indoor pollution. Typical ventilation system with components and operating modes. Design of a ventilation system and choice of air filters based on the mass balance of contaminants in a confined environment. Position and purpose of air cleaners. Bioaerosols: viable and non-viable. Bioaerosols size range, aerosolization, and sampling. Aerosol emission by humans. Health effects of bioaerosols. Respiratory deposition and health hazards. Respiratory system. Particle clearance mechanisms. Inhalable, thoracic, and respirable fractions. Performance assessment of personal protection equipment for the respiratory tract, medical masks, and community face coverings. Atmospheric aerosols. Natural and anthropogenic sources of particles. Charging ions in the atmosphere. Typical modal parameters for an urban aerosol. Nucleation, accumulation and coarse mode in urban aerosols. Global effects of atmospheric aerosols. Electrical properties of aerosols. Charging mechanisms. Corona discharge. Boltzmann equilibrium charge distribution. Electrostatic precipitators. Optical properties of aerosols. Light scattering. Optical diameter. Mie theory. Optical particle spectrometers and photometers. Condensation Nuclei Counter. Electrical mobility diameter. Differential Mobility Analyzer. Scanning Mobility Particle Sizer (SMPS). Aerosol sampling. Particle condensation and evaporation. Laboratory applications: • Calculation of PM indoor concentration. Effect of supply airflow rate, air filter efficiency, and internal generation on particulate contamination in the occupied environment. • Air filter performance assessment. Measurement of the resistance to airflow as a function of the airflow rate and correction to reference air density. Determination of the filter fractional efficiency values. Calculation of ePMx rating following a PM-based approach. • Calculation of the properties of lognormal distributions using a set of plastic spheres to represent a polydisperse aerosol at a 1000:1 scale. Students’ project: Use of low-cost PM sensors. Literature search. Analysis of a scientific paper taken as a reference for the student's final report. Working with the Arduino Module and importing data from sensors. Using software tools to import the data and analyze them. Support for assembling and programming the low-cost PM sensor module used for the project

Students will develop a hands-on project about particulate matter monitoring or measurement. Additional information is available with a video at this link: https://youtu.be/OpFWb2JAm84 Other information is also available at: https://aerosoltech.polito.it

Experimental activities will support theoretical lectures and application exercises. Laboratory practices will help the student learn the measurement techniques of airborne particles and understand the mechanisms of particle generation, transport, and loss. The students will understand the control technologies of airborne pollutants and learn how to choose among them. The students, in teams, will develop a research project on aerosol technology, focusing on air quality assessment and control. They will produce a technical research report describing their motivation, literature review, methods, and results and summarize their research with a presentation. If the circumstances allow, the course will include a guided visit to a measuring station or a manufacturing facility. Students will complete three individual assignments, primarily to encourage critical thinking about relevant topics covered in the course. Both the research project and the assignments will contribute to the final grade.

Hinds W.C., Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles, Wiley, 1999. Kulkarni P., Baron P., Willeke K., Aerosol Measurement: Principles, Techniques, and Applications, Wiley, 2011. Seinfeld J.H., Pandis S.N., Atmospheric Chemistry and Physics - from Air Pollution to Climate Change, Wiley, 2006. Lecture notes.

Lecture slides; Text book; Lab exercises; Video lectures (previous years);

Exam: Compulsory oral exam; Group project;

Concerning the project mentioned above, students will perform a detailed analysis and format their report as a formal research article/conference paper. As part of the exam, students will complete a final report (one week in advance before the exam or the date agreed upon before the exam) and present it. That includes also answering questions and clarifying doubts. This part is intended to assess the student's ability to understand and put into practice the knowledge provided by the lectures and the laboratories. Three homework assignments during the course will combine hand calculations, spreadsheet development, and learning the basics of some software packages typically used in the field. The students will complete the homework before the final exam. This part aims to evaluate the ability to apply what was learned but cannot be evaluated through the project and its presentation. Course grades will be determined by the total number of points accumulated through the project and the assignments. Each category's maximum total number of points is: - Assignments (in due time): 15/32 points - Project report: 8/32 points - Project presentation and discussion: 9/32 points The students unable or willing to perform the project will take an oral exam. For those students, each category's total number of points is: - Oral exam about assignments: 15/30 points - Oral exam about theory: 15/30 points

In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.