Define parameters local to a notebook section

Question

Is there a way to split a Mathematica worksheet, so that I can define parameters that are valid only for a section of the worksheet, like "local parameters" of a Matlab or C++ function?

1. I need a solution that does not require clearing the parameter each time and assigning them values again please.

2. I don't want to worry which part of the code I write above or below another.

For a minimal example:

In this section I assign value for C and Q, which should be valid in this section only:

 C=1; 
 f[x_]:=Sin[x*C] 
 Q=NIntegrate[f[x],{x,0,1}] 

In this section I want the parameters to remain free, but not to have to clear them, or define a whole different set of parameter names. The problem with the this trivial solution is that I have too many parameters so it is simply very annoying to do so. -->:

 f[x_]:=Sin[x*C] 
 Q=Integrate[f[x],{x,0,1}]  

Thanks!

Update1: Maybe my question is more clear as follows:

Is there a way to split the Mathematica worksheet, such that different section of it will work on different kernels?

Update2: I am looking for something that works like

 Block[{C = 1}, Q = Exp[C]], 

but for more then one calculation, namely for a whole section of the worksheet.

Answer 1

One possibility is to add sections for grouping, and then change the CellContext option of input cells to CellGroup. Then all of the input cells in a section will use the context of the cell group, which will be different for each section. As an example, here is some code to create a notebook with multiple sub-sub-sections, with an input cell in each section, and with a style sheet that gives input cells the option CellContext->CellGroup:

CreateDocument[
    {
    TextCell["Subsection 1", "Subsubsection"], 
    ExpressionCell[Defer[x=1], "Input"],
    TextCell["Subsection 2", "Subsubsection"],
    ExpressionCell[Defer[x], "Input"]
    },
    StyleDefinitions->Notebook[
        {
        Cell[StyleData[StyleDefinitions->"Default.nb"]],
        Cell[StyleData["Input"],CellContext->CellGroup]
        },
        StyleDefinitions->"PrivateStylesheetFormatting.nb"
    ]
];

And here is an animation showing the evaluation of each input cell in the created notebook: