https://www.physlab-wiki.com/ 2026-04-17T08:15:09+00:00 https://www.physlab-wiki.com/ https://www.physlab-wiki.com/lib/tpl/UChicago/images/favicon.ico text/html 2023-05-05T17:48:03+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/atomic-and-molecular-spectra-and-oximetry?rev=1683323283&do=diff Atomic and molecular spectra and applications in oximetry This will be a two week lab. In the first week, we will be using the principles of diffraction to study the absorption and emission spectra of atomic gases. We will then see in the second week how analyzing the absorption spectrum of a substance can be of great use and importance in medicine and biosciences. In particular, you will develop your own “oximeter”, an important apparatus used in medicine to measure the saturation of oxygen in… text/html 2023-06-16T11:07:06+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/cell-membrane-potentials-as-complex-circuits?rev=1686928026&do=diff Cell membrane potentials as complex circuits When we first encounter electrical circuits in lecture, it is easy to get lost in an abstract sea of squiggles with no immediate applications. But these squiggles are an incredibly powerful tool that can allow us to understand the biological mechanisms that permit you to read this text. Indeed, the nerve impulse that is generated when a photon from the computer screen hits your retina and interacts with light-sensitive cells travels along the optic n… text/html 2024-01-16T13:16:22+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/electric-field-mapping?rev=1705428982&do=diff Electric Fields Part 1 Field Mapping In mechanics, we learned how to compute forces between different objects in order to determine how these objects would move. In many cases, we considered the forces between two simple objects at a single point --$\mathbf{F}$$q$$\mathbf{E}$$\mathbf{E} = \dfrac{\mathbf{F}}{q}$$(1)$$+Q$$+q$$+Q$$Q$$+q$$+Q$$\mathrm{b}$$f_1$$+Q$$f_2$$-Q$$R$$\mathrm{b}$$+Q$$+q$$+q$$V = \dfrac{W}{q}$$(2)$$V$$W$$q$$V$$\mathrm{B}$$\mathrm{C}$$\mathrm{B}$$a$$b$$\mathrm{B}$$\mathrm{C}$… text/html 2024-01-29T16:27:19+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/electrophoresis-of-pigments-2-v2?rev=1706563639&do=diff Electric Fields Part 3: Electrophoresis of pigments - testing the model In last week's lab, you started investigating the electrophoresis of pigments in chromatography paper. You saw that different pigment molecules seem to have different charge to mass ratios that affect how they move in the presence of an electric field. More specifically, these different ratios result in different terminal velocities, which allowed you to use the method to separate a mixture of pigments based on their proper… text/html 2023-11-06T11:29:16+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/electrophoresis-of-pigments-2?rev=1699288156&do=diff Electric Fields Part 3: Electrophoresis of pigments in chromatography paper, cont. In last week's lab, you started investigating the electrophoresis of pigments in chromatography paper. You saw that different pigment molecules seem to have different charge to mass ratios that affect how they move in the presence of an electric field. More specifically, the different ratios result in different terminal velocities, so that electrophoresis serves as a useful mechanism to separate mixture of molecu… text/html 2024-01-26T17:16:48+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/electrophoresis-of-pigments-v2?rev=1706307408&do=diff Electric Fields Part 2 Electrophoresis of Pigments in Chromatography Paper In last week's lab, you mapped out the electric fields for different configurations of charged electrodes in a tub of water. While you had the liberty to choose your configurations, we asked you to map the field given by oppositely charged parallel plates, which by now you know is given by $\vec{E} = \frac{V}{d}\hat{d}$$V$$d$$\hat{d}$$\text{SiO}_2$$\text{SiOH}$$\text{H}^+$$\text{H}_2\text{O}$$\text{SiO}^-$$q$$q$$\vec{E}… text/html 2024-01-04T13:05:18+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/electrophoresis-of-pigments?rev=1704391518&do=diff Electric Fields Part 2 Electrophoresis of Pigments in Chromatography Paper In last week's lab, you mapped out the electric fields for different configurations of charged electrodes in a tub of water. While you had the liberty to choose your configurations, we asked you to map the field given by oppositely charged parallel plates, which by now you know is given by $\vec{E} = \frac{V}{d}\hat{d}$$V$$d$$\hat{d}$$\text{SiO}_2$$\text{SiOH}$$\text{H}^+$$\text{H}_2\text{O}$$\text{SiO}^-$$q$$q$$\vec{E}… text/html 2023-03-28T17:55:00+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.physlab-wiki.com/phylabs/lab_courses/phys-120_130-wiki-home/new-120s/electrophoresis-of-silica-microspheres?rev=1680040500&do=diff Electrophoresis of silica microspheres in water In this experiment, we will be studying electrophoresis, the motion of charged particles suspended in a medium when they are subjected to an electric field. The dynamics of charged objects in aqueous media is particularly relevant in the study of living systems. Charged particles, such as proteins and ions in cells, generate electric fields that that act on other charged particles, forming the basis for many transport phenomena in living systems. …