From 4ddc0bcecdd172e6fbed0df2e80dfc7663b6ab73 Mon Sep 17 00:00:00 2001 From: Blaise Thompson Date: Sun, 12 Nov 2017 18:51:13 -0600 Subject: structure --- public.tex | 120 ------------------------------------------------------------- 1 file changed, 120 deletions(-) delete mode 100644 public.tex (limited to 'public.tex') diff --git a/public.tex b/public.tex deleted file mode 100644 index 9c859e7..0000000 --- a/public.tex +++ /dev/null @@ -1,120 +0,0 @@ -% http://scifun.chem.wisc.edu/Thesis_Awards/chapter_guidelines.html - -\chapter{Public} - -\section{Chemical systems} % --------------------------------------------------------------------- - -Chemical systems are complex! % -They contain many molecules ($10^{25}$ in a cup of coffee, 1 trillion in each human cell). % -These molecules have multiple interaction modes, both internal (intramolecular) and external -(intermolecular). % -The reactivity of the system taken as a whole can be dominated by very rare but very important -species, \textit{e.g.} catalysts. % - -Despite this complexity, scientists have gotten very good at describing chemical systems through -representations of dynamic equilibrium. % -In such situations, several key parameters emerge: % -\begin{itemize} - \item concentration - \item timescale (rate) - \item lengthscale -\end{itemize} - -\subsection{Concentration} - -\subsection{Timescale} - -% TODO: dynamics in chemical systems: collision time, dephasing, rotation, relaxation, diffusion... - -\subsection{Lengthscale} - -\section{Analytical chemistry} % ----------------------------------------------------------------- - -Traditionally, chemists have seen fit to divide themselves into four specializations: analytical, -inorganic, organic, and physical. % -In recent years, materials chemistry and chemical biology have become specializations in their own -right. % -This dissertation focuses on analytical chemistry. % - -Analytical chemists separate, identify, and quantify chemical systems. % -To do this, we build instruments that exploit physical properties of the chemical components: % -\begin{itemize} - \item separation science (chromatography, electrophoresis) - \item mass spectrometry - \item electrochemistry - \item microscopy - \item spectroscopy -\end{itemize} -Spectroscopy is a family of strategies that exploit the interaction of chemical systems with -light. % - -\section{Spectroscopy} % ------------------------------------------------------------------------- - -Molecules respond to electric fields. % -Static electric fields cause charged molecules (ions) to move, as in electrophoresis and mass -spectrometry. % -Oscillating electric fields, also known as light, can interact directly with the molecules -themselves, driving transitions. % -However, these transitions can only be driven with the appropriate frequency of light -(resonance). % -Different frequencies (colors) of light interact with different kinds of transitions, revealing -different features of the molecule of interest. % - -% TODO: different energy ranges / transition types (nuclear, rotational, vibrational, electronic) - -% TODO: how is a photon created or absorbed? - -\subsection{Nonlinear spectroscopy} - -Spectroscopy is fantastic, but sometimes simple experiments don't reveal everything. % -Nonlinear spectroscopy uses multiple electric fields simultaniously, revealing even more -information about the chemical system. % - -% TODO: simple graphic of homogeneous vs inhomogeneous broadening - -% TODO: 2D freq-freq with increasing inhomogeneity (from Dan's theory work) - -\section{Instrumentation} % ---------------------------------------------------------------------- - -To accomplish nonlinear spectroscopy, specialized light sources are needed: % -\begin{itemize} - \item gigantic electric fields - \item ultrafast time resoution - \item tunable frequencies -\end{itemize} - -\subsection{LASER} - -These sources are made using Light Amplified by the Stimulated Emission of Radiation (LASER). % - -% TODO: discussion of the original LASER, basic LASER physics - -% TODO: discuss temporal coherence - -% TODO: discuss pulsed sources - -By keeping a wide range ofr colors in phase simulatniously, we are able to create truly ultrafast -pulses of light. % -The work presented in this dissertation was primarily taken using a 35 fs 1 KHz system. % - -35 fs ($35\times10^{15}$ second) pulses are incredibly short: -\begin{equation} - \frac{\text{pulse duration (35 fs)}}{\text{time between pulses (1 ms)}} \approx - \frac{\text{5.75 months}}{\text{age of universe (13.7 billion years)}} % TODO: cite age -\end{equation} -proportionally, our sample spends 6 months in the ``sun'' for every age of the unverse in the -dark. % - -Because all of the energy within the pulse is compressed to such a short period of time, these -pulses are also incredibly powerful: -\begin{equation} - \frac{\text{energy per pulse (4 mJ)}}{\text{pulse duration (35 fs)}} \approx - \frac{\text{US electricity generation} (5.43\times10^{11} W)}{5} % TODO: cite generation -\end{equation} -this laser outputs electric fields one fifth as powerful as total US electricity generation (2016). - -% TODO: pulses are very thin (draw circle, use thickness of paper) to motivate 'hard to handle' - -\subsection{OPA} - -% https://osf.io/vwhjk/ \ No newline at end of file -- cgit v1.2.3