Applied physics

A.Y. 2016/2017
Lesson for
Overall hours
Learning objectives
The purpose of this course is twofold:
- Consolidate the basic concepts essential for understanding molecular and biomolecular phenomena and technologies. Particular emphasis will be given to thermodynamics and to the proper use of the concept of energy;
- Introduce the basics of fluorescence and of optical microscopy, thereby allowing a proper understanding of some biotechnological basic methodologies.
In this class the student: (i) learns about the physical quantities of importance in the field of Biotechnologies, with a specific emphasis on thermodynamic quantities, and about their units of measurements; (ii) learns to use such quantities in quantitative problems; (iii) learns about the physical and technological foundations of optical microscopy and fluorescence.

Course structure and Syllabus

Active edition
Practicals: 24 hours
Lessons: 60 hours
Introduction to quantitative description of motions
Introduction to the physical quantities and to the proper use of their transformations
Description of the motion of bodies: space dimensions, velocity, acceleration, decomposition of the motion along orthogonal axes, parabolic motion, range of a projectile
The three laws of motion, the definition of mass and strength
Introduction to different types of forces: weight, static and dynamical friction force, reaction force,
elastic force
Introduction to the description of the fluids: pressure in a fluid, Stevino law, Archimedes force, the viscous friction (definition and viscous friction force on a sphere)
Work of forces
Kinetic energy theorem
Conservative and non-conservative forces
Potential energy (with examples containing elastic force and weight)
Conservation and dissipation of mechanical energy, definition of power

Zero law of thermodynamics: thermal contact
Thermometers and definition of thermometric scales (Kelvin and Celsius)
Heat and calorie
Thermal contact and thermal equilibrium
State equation of an ideal gas
Kinetic theory of gases (microscopical description of temperature, principle of energy equipartition)
Equivalence of work and heat (Joule experiment)
First law of thermodynamics
Transformations of an ideal gas (isothermal, isobaric, isochoric, adiabatic)
Internal energy and interaction potential
Thermalization and Boltzmann distribution (activated dynamics)
Random walk (and random chain) and diffusion (diffusion coefficient, Fick's law)
Second law of thermodynamics (Clausius, Kelvin)
Carnot cycle, thermal engine and yield
Definition of entropy
Irreversible processes in an isolated system (free expansion, thermalization of two bodies in
contact), yield of irreversible engines, lost work and energy degradation
Statistical description of entropy (the configuration and velocity space)
Free energy

Electrostatic and optics
Electric charge and Coulomb force,
Electrostatic potential energy, electric field, electric potential
Insulating and conducting materials (metals and electrolytes)
Electric current, resistance, global and local Ohm's laws
Joule effect
Nature of electromagnetic radiation: frequency, velocity of propagation, wavelength, wavevector
Spectrum of the radiation, light radiation, radiation power
Refractive index, refraction, total reflection

Physical basis of fluorescence and optical microscopy
Introduction to the concept of images and optical image formation by lenses.
Convergent and divergent lenses. Real and virtual images. Lens aberrations (chromatic aberration,
spherical aberration, field curvature).
Main properties of most used light sources (incandescent lamp, arc lamp, led and
laser) and light detectors (photodiodes, CCD, photomultipliers).
Introduction to light spectra. Methods of discriminating wavelengths in a spectrum
(dichroic filters and diffraction gratings).
Introduction to spectral measurements and to the basic structure of the spectrophotometer.
Introduction to fluorescence and to the basic structure of fluorimeters. Introduction to FRET.
Introduction to the structure of optical microscopes: optical components and microscope geometries; conjugated planes.
Magnification and resolution. Role of the numerical aperture in the resolution.
Illumination in the microscope. Use of the condenser.
Microscopy in bright field and in dark field, fluorescence microscopy, polarized microscopy,
phase contrast microscopy.
Lesson period
Second semester
Lesson period
Second semester
Assessment methods
Assessment result
voto verbalizzato in trentesimi