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% Document Info
\author{eyeeyuu}
\pdfinfo{
  /Title (uv-and-fluorescence-spectroscopy.pdf)
  /Creator (Cheatography)
  /Author (eyeeyuu)
  /Subject (UV \& Fluorescence Spectroscopy Cheat Sheet)
}

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\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
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    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
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\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{UV \& Fluorescence Spectroscopy Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{eyeeyuu} via \textcolor{DarkBackground}{\uline{cheatography.com/159905/cs/33689/}}}
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\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}eyeeyuu \\
  \uline{cheatography.com/eyeeyuu} \\
  \end{tabulary}
\vfill
\columnbreak
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  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 17th August, 2022.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
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  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
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\end{multicols}}




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\begin{multicols*}{2}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{UV SPECTROSCOPY}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660652573_Screenshot 2022-08-16 at 13.20.10.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{Chromophore = portion of a molecule that absorbs light \newline  \newline Conjugated structure = 2+ adjacent C=C double bonds \newline More pi-electrons = more conjugated double bonds \newline ↳ compound will absorb more light and have a longer wavelength and chromophore}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Analytical purposes}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{When a beam of radiation is passed through a sample, \{\{nl\}\} - some radiation is {\bf{absorbed}} by the sample \{\{nl\}\} - some radiation is {\bf{reflected}} or {\bf{scattered}} \{\{nl\}\} - some radiation {\bf{passes}} straight through} \tn 
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% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{For analytical purposes, we are interested in the {\bf{amount ABSORBED}} by the sample and so we want to eliminate reflection and scattering.} \tn 
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% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{This is done by: \{\{nl\}\} - taking I0 as the intensity of the light passing through a cell when filled with a {\bf{blank solution}} (everything except substance being measured) \{\{nl\}\} taking I as the intensity passing through the cell when filled with the {\bf{sample}}} \tn 
% Row Count 14 (+ 6)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Calculating transmittance}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660653099_Screenshot 2022-08-16 at 13.31.09.png}}} \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Equations}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660653301_Screenshot 2022-08-16 at 13.34.46.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Beer-Lambert Law}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{Beer-Lambert law= dependence of absorption on concentration and path length} \tn 
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\mymulticolumn{1}{x{8.4cm}}{{\bf{A=acl}}} \tn 
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% Row 2
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\mymulticolumn{1}{x{8.4cm}}{a = absorption coefficient \{\{nl\}\} Represents the absorbance of a solution of unit concentration when measured in a cell of unit path length} \tn 
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\end{tabularx}
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\begin{tabularx}{8.4cm}{x{2.4 cm} x{5.6 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Quantitative analysis}}  \tn
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\SetRowColor{LightBackground}
\mymulticolumn{2}{x{8.4cm}}{Two methods are used to convert the measured absorbance into a concentration: \{\{nl\}\} 1. Calibration curve \{\{nl\}\} 2. Using the Beer-Lambert law with a given 'a' value} \tn 
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% Row 1
\SetRowColor{white}
Calibration curve & 5 or more standards are prepared from a sample of pure material to be determined. Their absorbance is measured and their values are used to construct a calibration curve. \{\{nl\}\} The sample absorbance is measured and its concentration is read off the curve. \{\{nl\}\} {\bf{A pure analyte sample must be available}} \tn 
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\seqsplit{Beer-Lambert} law & Use of {\bf{A=acl}} will be needed with additional steps to work out the dilution factor \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Relationship between path length and concentration}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660653221_Screenshot 2022-08-16 at 13.31.18.png}}} \tn 
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\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{The value of T (or I) depends on the cell's path length, concentration of absorbing substances and the nature of the substance. \newline - Increased path length = decreased intensity → light passes MORE through solution and interacts MORE with molecule}  \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Wavelength selection}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660654223_Screenshot 2022-08-16 at 13.38.30.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{The wavelength for the assay should be chosen so that only the substance of interest absorbs, with no impurities}}}  \tn 
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\end{tabularx}
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Analysis of mixtures}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660654460_Screenshot 2022-08-16 at 13.53.22.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{If we assume that the components of the mixture do not react with one another, then the absorbance at some wavelength = the sum of absorbance for each component}  \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Mixture of 2 substances}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660654736_Screenshot 2022-08-16 at 13.49.56.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{For a mixture of 2 substances with different chromophores, each will have different powers of light absorption at some wavelength(s) in the spectrum. \newline If measurements are made on the mixture at 1 and 2, then a pair of simultaneous equations can be set up to find the unknown concentrations.}  \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{FLUORESCENCE SPECTROSCOPY}}  \tn
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\mymulticolumn{1}{x{8.4cm}}{What is fluorescence?} \tn 
\mymulticolumn{1}{x{8.4cm}}{\hspace*{6 px}\rule{2px}{6px}\hspace*{6 px}When molecules absorb UV-visible radiation, they absorbed energy is converted into kinetic energy due to collisions. \{\{nl\}\} A few excited molecules get rid of excess energy by emitting the absorbed energy as light = {\bf{FLUORESCENCE}}} \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Why use fluorescence?}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{Fluorescence is more selective than absorption of energy \{\{nl\}\} ↳ The chances of finding 2 substances which absorb {\bf{and emit}} at the same wavelength is {\bf{LESS}} than finding 2 substances that absorb at the same wavelength} \tn 
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% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{Not all substances fluoresce \{\{nl\}\} ↳ Advantage: it makes fluorimetry more selective for compounds that fluoresce \{\{nl\}\} Disadvantage: not all compounds fluoresce} \tn 
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% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{It's more selective than absorption spectrophotometry} \tn 
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\end{tabularx}
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Process of fluorescence}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660733496_Screenshot 2022-08-17 at 11.49.15.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{- The emitted radiation is of lower energy than the absorbed radiation \newline - Molecules in the ground state absorb light and are excited to a vibrational level in the 1st excited state \newline - Excess vibration is then lost by collisions with other molecules until they are in the V=0 level of the 1st excited state \newline - The molecules get rid of the remaining energy by emitting it as radiation and dropping to a vibrational level in the ground state}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
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\begin{tabularx}{8.4cm}{x{3.04 cm} x{4.96 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Types of fluorescence}}  \tn
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\SetRowColor{LightBackground}
{\bf{1. Chemi-luminescence}} & When the product molecules are left in an excited state, light is emitted when the molecules return to the ground state \tn 
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{\bf{2. Bio-luminescence}} & Biochemical reactions that produce light \tn 
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\end{tabularx}
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Relationship between structure and fluorescence}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{e.g. Fluorescein → fluorescent and rigid structure (prevents loss of energy) \newline e.g. Phenolphthalein → non-fluorescent and non-rigid structure (can twist which converts its absorbed energy into rotational and vibrational energy)}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\begin{tabularx}{8.4cm}{x{4.8 cm} x{3.2 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Fluorescence enhancers and inhibitors}}  \tn
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Fluorescence enhancers & Fluorescence inhibitors \tn 
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OH, OCH3, NH2, NHR, NR2 \{\{nl\}\} ↳ Increase the no. of delocalised electrons & COOH, NO2, NO, F, Cl, Br, I \tn 
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\end{tabularx}
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Factors affecting fluorescence intensity}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660736449_Screenshot 2022-08-17 at 12.09.50.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{More energy absorbed = more energy emitted \newline Intensity of fluorescence is PROPORTIONAL to amount of light absorbed \newline  \newline Relationship between I0 and I given by the Beer-Lambert law \newline - Intensity of emitted radiation is directly proportional to conc \newline - Fluorescence is directly proportional to intensity of excitation state \newline ↳ brighter lamp = greater fluorescence \newline - Fluorescence depends on molar absorption coefficient (E) \newline ↳ stronger absorbance = greater fluorescence}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Fluorescence intensity vs. concentration}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660737173_Screenshot 2022-08-17 at 12.50.47.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{At high concentrations, the fluorescence emission becomes concentrated near the {\bf{sides of the sample cell}} to which the exciting radiation enters. \newline As the exciting radiation passes through the sample, its intensity falls and the fluorescence produced also decreases. \newline  \newline {\bf{Under these conditions, the equation for fluorescence intensity no longer holds (as Ecl is no longer small}}}  \tn 
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\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Experimental measurement of fluorescence}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{p{8.4cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/eyeeyuu_1660736972_Screenshot 2022-08-17 at 12.44.54.png}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{1. Light source}} \newline - As intense as possible at wavelength of max absorption \newline - Continuous source \newline - Wavelength region of 200-500nm \newline  \newline {\bf{2. Excitor and detector monochromator}} \newline - Used to select excitation/emission wavelengths \newline - Low diminishing and high light gathering powers \newline - Filters can be used but are less versatile \newline  \newline {\bf{3. Sample cell}} \newline - Usually silica \newline - 1x1cm \newline - 4 clear, optically worked surfaces \newline  \newline {\bf{4. Detector}} \newline - Must be sensitive as possible (varies) \newline - Photomultiplier tube}  \tn 
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\begin{tabularx}{8.4cm}{x{3.52 cm} x{4.48 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Factors affecting fluorescence measurements}}  \tn
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{\bf{1. Lower limit of detection}} & Lowest concentration of substance that can be determined \tn 
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{\bf{2. Fluorescent impurities}} & Usually from the reagents or from the cell \{\{nl\}\} Ensure the cell is clean and is always placed in the same way (as the 4 sides have different background intensities) \tn 
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{\bf{3. Photodecomposition}} & The sample can undergo decomposition due to the high intensity of the exciting radiation samples, and standards should NOT be exposed to the radiation longer than necessary \tn 
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{\bf{4. Quenching}} & Substance fluorescence is affected more by its environment then the absorption of the sample \{\{nl\}\} {\bf{Quenching = when fluorescence is decreased by the presence of another sample}} \tn 
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% That's all folks
\end{multicols*}

\end{document}