A method to reduce memory requirements for a packet loss concealment algorithm in the event of packet loss in a receiver of pulse code modulated voice signals. The flat plates have the same length as an inner diameter of a collecting part 6, and are formed at central positions thereof with slits S1 and S2 facing each other to be joined with each other like a cross shape. Also disclosed herein are azeotropic or near azeotropic refrigerant and heat transfer fluid compositions comprising 1,1,1,2,2,4,5,5,5-nonafluoro-4–3-pentanone and at least one hydrocarbon.