A novel solid polymer electrolyte: Synthesis and characterization

Summary A new polyether network was prepared using a polyethylene oxide (PEO) triol and a PEO diisocyanate, the latter component arising from the chemical modification of commercial PEO diamines. The physico-chemical properties of the network alone and with LiClO₄ were assessed in comparison with those of previously obtained structures. Ionic conductivities were found to be higher with this new system. Replacement of LiClO₄ by LiN(CF₃SO₂)₂ improved the conductivity further because of the plasticizing role of the imidic anion.     

The reactivity of 2-furaldehyde and its derivatives in polymerisation reactions involving the carbonyl bond

The homopolymerisation of 2-furaldehyde, 5-methyl-2-furaldehyde and 2-furyl methyl ketone and their cationic copolymerisation (BF₃. Et₂) with olefins were investigated. All attempts to obtain homopolymers failed because of thermodynamic restrictions. 2-Furaldehyde and α-methylstyrene gave an alternating copolymer of low degree of polymerisation, 2-methyl-2-furaldehyde and α-methylstyrene gave copolymers rich in 5-methyl-2-furaldehyde, indicating a penultimate effect in the growth mechanism. The use of less basic comonomers (cyclopentadiene, styrene, isoprene, etc.) resulted in inhibition or strong retardation of the polymerisation. The use of more basic comonomers (acenaphthy-lene, N-vinylcarbazole) resulted in their homopolymerisation. Furyl methyl ketone inhibited the polymerisation of all comonomers tried. A complex between BF₃. Et₂O and 2-furaldehyde was isolated and characterised. A general mechanism is offered to explain the behaviour of these systems.     

Electrolytes for solid-state batteries: glass transition temperature of polyether networks with and without alkali metal salts

Summary A detailed study was conducted on the dependence of the Tg of polyether networks as a function of type and size of polyether chain, nature of the crosslinking structure and alkali metal salt concentration. The nature of the branching moiety affects Tg but not the salt interactions with the network. A general law concerning the salt-containing network is obtained. It is characterized by the dominating interactions of the salt with polyethylene oxyde chains.This work has thus allowed the establishment of further general features characterizing the behaviour of polyether networks containing ionic species.     

Mechanism of ionic conduction in polyether-polyurethane networks containing lithium perchlorate

The swelling behaviour of polyethylene oxide-urethane networks (with and without LiClO₄) was studied with several organic liquids and water. All the results are consistent with a model for the network-salt interaction involving the solvation of Li⁺ ions by oxygen atoms of the ether. More specifically, strong interactions take place between ionic quadrupoles and two polyether chains leading to reversible physicochemical (ionic) crosslinks. The number of such interactions grows with salt concentration up to a limit characterised by one ionic crosslink every twelve ethylene oxide units. An ionic transport mechanism (conduction) is proposed on the basis of this model considered in a dynamic context.     

Performance of Cinta Senese pigs and their crosses with Large White 2. Physical, chemical and technological traits of Tuscan dry-cured ham

Technological, chemical and physical traits of cured ham from Cinta Senese and Large White pigs, and their crosses were investigated. Hams were obtained from 29 Cinta Senese (CS), 29 Large White × Cinta Senese (LW × CS) and 12 Large White (LW) pigs, fed a commercial mixture. Sensory and chemical–physical analysis was performed on a sample-slice and on muscles (Biceps femoris – BF; Semimembranosus – SM; Semitendinosus – ST) and subcutaneous fat. CS showed the highest trimming loss and the lowest salting loss. Hams of CS pigs scored higher for fatness than those of LW pigs, LW × CS showing intermediate values. On sample-slice, CS exhibited higher firmness, redness and marbling of lean, and greater fat extension than LW, with crosses having intermediate scores. Muscle moisture was lowest in CS, while both SM and BF from LW had the highest percentage of protein and the lowest of ash. CS showed higher intramuscular fat content than LW × CS and LW. Shear force of BF was higher in CS than in LW × CS and LW. With respect to LW, CS had lower values of L^* in muscles, and higher values of a^* in subcutaneous fat. Subcutaneous fat of CS contained less SFA and more MUFA than LW × CS and LW.     

Selection with inbreeding control in simulated young bull schemes for local dairy cattle breeds

Local breeds are rarely subject to modern selection techniques; however, selection programs will be required if local breeds are to remain a viable livelihood option for farmers. Selection in small populations needs to take into account accurate inbreeding control. Optimum contribution selection (OCS) is efficient in controlling inbreeding and maximizes genetic gain. The current paper investigates genetic progress in simulated dairy cattle populations from 500 to 6,000 cows undergoing young bull selection schemes with OCS compared with truncation selection (TS) at an annual inbreeding rate of 0.003. Selection is carried out for a dairy trait with a base heritability of 0.3. A young bull selection scheme was used because of its simplicity in implementation. With TS, annual genetic gain from 0.111 standard deviation units with 500 cows increases rapidly to 0.145 standard deviation units with 4,000 cows. Then, genetic gain increases more slowly up to 6,000 cows. At the same inbreeding rate, OCS produces higher genetic progress than TS. Differences in genetic gain between OCS and TS vary from to 2 to 6.3%. Genetic gain is also improved by increasing the number of years that males can be used as sires of sires. When comparing OCS versus TS at different heritabilities, we observe an advantage of OCS only at high heritability, up to 8% with heritability of 0.9. By increasing the constraint on inbreeding, the difference of genetic gain between the 2 selection methods increases in favor of OCS, and the advantage at the inbreeding rate of 0.001 per generation is 6 times more than at the inbreeding rate of 0.003. Opportunities exist for selection even in dairy cattle populations of a few hundred females. In any case, selection in local breeds will most often require specific investments in infrastructure and manpower, including systems for accurate data recording and selection skills and the presence of artificial insemination and breeders organizations. A cost-benefit analysis is therefore advisable before considering the implementation of selection schemes in local dairy cattle breeds.