Dim productID = 100
Using context As New AdventureWorksEntities()
    Dim queryString As String = "SELECT VALUE product FROM AdventureWorksEntities.Products AS product " & _
            " WHERE product.ProductID < @productID"
    Dim productQuery As New ObjectQuery(Of Product)(queryString, context, MergeOption.NoTracking)

    Dim productQuery2 As New ObjectQuery(Of Product)(queryString, context, MergeOption.NoTracking)

    Dim productQuery3 As ObjectQuery(Of Product) = productQuery.Union(productQuery2)

    productQuery3.Parameters.Add(New ObjectParameter("productID", productID))

    Console.WriteLine("Result of Union")
    Console.WriteLine("------------------")

    ' Iterate through the collection of Product items, 
    ' after the Union method was called on two queries. 
    For Each result As Product In productQuery3
        Console.WriteLine("Product Name: {0}", result.ProductID)
    Next
End Using