def remove_nan_columns(dataframe):
    """Removes columns of data frame where any value is NaN.

    Args:
        dataframe (pandas.DataFrame):  Input dataframe.

    Returns:
        tuple: tuple containing:
            pandas.DataFrame: Dataframe with columns containing NaN values removed.
            numpy.array: Array of bools indicating which columns were kept.
    """
    df_copy = dataframe.set_index("timestamp")
    selected_columns_mask = df_copy.notnull().all().values
    return dataframe.dropna(axis=1, how="any"), selected_columns_mask