="l00043"></a><span class="lineno">   43</span>&#160;Time Period</div>
<div class="line"><a name="l00044"></a><span class="lineno">   44</span>&#160;\begin{equation}</div>
<div class="line"><a name="l00045"></a><span class="lineno">   45</span>&#160;   [T]=\sage{Time_period}</div>
<div class="line"><a name="l00046"></a><span class="lineno">   46</span>&#160;\end{equation}</div>
<div class="line"><a name="l00047"></a><span class="lineno">   47</span>&#160;</div>
<div class="line"><a name="l00048"></a><span c