\documentclass[11pt]{article}
\usepackage[a4paper,margin=18mm]{geometry}
\usepackage{tikzphysics}
\pagestyle{empty}
\begin{document}
\section*{Percentage anchors and connected heat-transfer surfaces}
\begin{center}
\begin{tikzpicture}[>=latex,font=\small]
 \node[composite wall,rotate=20] (C) {};
 \foreach \p in {0,50,100}{
  \fill (C.interface-\p) circle (1.5pt);
  \node[right=3pt] at (C.interface-\p) {\p};
 }
 \node[below=20pt] at (C.south) {Interface: bottom to top};
 \node[radiating body,radiation ray length=.5cm] (R) at (7,0) {$T$};
 \foreach \p/\pos in {0/above right,25/above right,50/above left,75/below right}{
  \fill (R.rim-\p) circle (1.5pt);
  \node[\pos] at (R.rim-\p) {\p};
 }
 \node at (7,-2) {Rim: counterclockwise from the right};
\end{tikzpicture}
\end{center}
\bigskip
\begin{center}
\begin{tikzpicture}[>=latex,font=\small]
 \node[conduction slab,conduction width=.6cm,conduction height=3cm] (B) {$T_b$};
 \foreach \p in {20,50,80}{
  \node[cooling fin,fin length=3cm,fin base height=.7cm,anchor=heat-left] (F\p) at (B.right-\p) {};
  \draw[->] (F\p.axis-20)--(F\p.axis-60);
 }
 \node[below=12pt] at (B.south) {Three fins connected at percentage anchors on the base};
\end{tikzpicture}
\end{center}
The interface, radiating-body rim, and contact coordinates retain their direction
and location under rotation. Fin placement uses physical boundaries rather than
text padding or minimum-size settings.

\clearpage
\section*{Apparatus composition and contraction}
\begin{center}
\begin{tikzpicture}[>=latex,font=\small]
 \node[calorimeter,calorimeter width=4cm,calorimeter height=3.2cm,calorimeter level=.7] (C) {};
 \node[thermometer,fill=white,anchor=bulb-center,thermometer level=.65] (T) at ($(C.liquid-center)+(.7,0)$) {};
 \node at ($(C.liquid-center)+(-.5,0)$) {liquid};
 \node[below=10pt] at (C.south) {Thermometer bulb placed in the calorimeter liquid};
\end{tikzpicture}
\end{center}
\bigskip
\begin{center}
\begin{tikzpicture}[>=latex,font=\small]
 \node[expansion rod,expansion rod length=5cm,thermal expansion ratio=.85,rotate=10] (R) {};
 \foreach \p in {0,50,100}{
  \fill (R.expanded-\p) circle (1.4pt);
  \node[above=3pt] at (R.expanded-\p) {\p};
 }
 \node[right] at (R.expanded-end) {$0.85L$};
 \node[right] at (R.original-end) {$L$};
 \draw[densely dashed] (R.original-start)--(R.expanded-start);
\end{tikzpicture}
\end{center}
Both rod families run left to right. A ratio below one illustrates contraction;
it does not derive a coefficient of thermal expansion or a temperature change.
The liquid level and thermometer column remain independent author inputs.
\end{document}