def calc_bpe_exchange_current(K_standard_rate_constant, c_bulk_oxidized, c_bulk_reduced, alpha_transfer_coefficient=0.5):
    """
    The exchange current density at a specific BPE location
    units: Coulombs/s*m2
    Notes:
        K_standard_rate_constant: usually between 2 and 6
        c_bulk (oxidized and reduced) can be taken as just the concentration of the bulk species
        alpha is set to 1/2 in Adjari, 2006
    """
    e = -1.602e-19  # (C) charge of an electron

    j_0 = e * K_standard_rate_constant * c_bulk_reduced**alpha_transfer_coefficient * c_bulk_oxidized**(1-alpha_transfer_coefficient)
    return j_0