Porcine oocyte-cumulus complexes were cultured in bovine serum albumin(BSA)-free North Carolina State University (NCSU)23 medium containing porcine follicular fluid (10%), cysteine (0.1 mg/ml)and hormonal supplements (eCG and hCG: 10IU/ml each) for 22h. They were then cultured in the same medium but without hormonal supplements for an additional 22h. After culture, cumulus cells were removed and oocytes were co-incubated with frozen-thawed ejaculated boar spermatozoa in tissue culture medium (TCM)199 containing caffeine (5mM), fetal calf serum (FCS; 10%) and varying concentrations (26–56 mM)of NaHCO3 for 9h(experiment 1). In experiment 2, chlortetracycline (CTC) was used to assess the functional state of spermatozoa incubated under different NaHCO3 concentrations. Experiment 3 examined the effect of FCS (1% and 10%)and NaHCO3 (26 and 46 mM) on fertilisation parameters. Compared with 26 mM, penetration rate was significantly higher (p<0.05)at 36–56mM NaHCO3. Polyspermy showed a similar pattern although no difference was observed between 26 and 36 mM. At 46mM NaHCO3, the mean number of spermatozoa (MNS) penetrated per oocyte increased significantly (p< 0.05). A significantly higher proportion of spermatozoa were capacitated and acrosome reacted at 46 and 56mM NaHCO3, respectively. The fertilisation medium containing 46mM NaHCO3 and 1% FCS showed a higher penetration rate (84%)with a relatively low incidence of polyspermy (39%). The results indicate that NaHCO3 stimulates capacitation and/or the acrosome reaction of boar spermatozoa in a dose-dependent manner and thus affects fertilisation parameters.

Agglomerates of aligned crystals of CaxCo2O4 with a layer of CoO2 were grown using a chloride flux technique, and their thermoelectric properties in air were determined. The agglomerates take the form of a very thin flakelike cluster of crystals with a typical size of almost 3 × 2 × 0.07 mm. The values of thermoelectric power along the ab-plane are larger than 200 μV K−1 at temperatures above 873 K and reach almost 300 μV K−1 at 973 K. The temperature dependence of the electrical resistivity along the ab-plane shows bends around 450 and 825 K, and the ln ρab−T−1 curve followed an Arrhenius-type behavior below 450 K. Temperature dependence of thermal conductivity indicated that stacking faults along the c axis induce phonon scattering like that in a misfit-layered structure. The effect of the CoO2 layer on thermoelectric performance is discussed in comparison with related compounds.

We have grown single crystals of Bi-substituted Ca3Co4O9 by a solution method. The cationic ratio (Ca, Bi)/Co of the grown crystals measured by an energy dispersive X-ray spectrometer tended to exceed that of the starting ratio (Ca, Bi)/Co=3/4. For instance, the average cationic composition of the grown crystals was Ca:Bi:Co=3.3:0.3:4, while that of the starting material was Ca:Bi:Co=2.7:0.3:4. So, the crystallographic structure of the obtained crystals may correspond to the Ca2Co2O5 phase rather than the Ca3Co4O9 phase. Thermoelectric properties in the direction of ab-axis were measured at various temperatures. Seebeck coefficient (S) of Ca3.3Bi0.3Co4O9+δ is positive and increases with increasing temperature from 130 to 200 μV/K in a temperature region of 300–973 K. The electrical resistivity (ρ) of the sample is about 1.5 mΩcm at whole temperature region of 300–973 K. This value is lower than that of non-substituted Ca3Co4O9. The thermoelectric power factor (S 2/ρ) is improved by the Bi-substitution, resulting from the reduction of resistivity.

A high-throughput screening technique has been developed and was utilized in the discovery of a new n-type oxide possessing good thermoelectric properties. Screening of metal binary systems consisting of 3d transition metals using this technique showed LaNiO3 to possess the desired n-type properties. Electrical resistivity (ρ) of this oxide is favorably quite low, however, the Seebeck coefficient (S) is as small as –25 μV/K. To enhance the thermoelectric properties of LaNiO3, high-throughput screening was employed to examine candidates from the metal ternary La1–xMxNiO3 and LaNi1–xNxO3 systems. Bi substitution in the La1–xMxNiO3 systems and Cu substitution in the LaNi1–xNxO3 systems were found to be effective for improvement of S and ρ respectively.

We report preparation of highly grain-aligned and densified [Ca2CoO3-δ]0.62CoO2 bulks and a change of thermoelectric performance for their bulks with different oxygen deficiencies (dgrl). The highly c-axis aligned and highly densified samples which showed low electronic resistivities at room temperature, were obtained by combination of magnetic alignment and spark plasma sintering methods. Electronic resistivity p and Seebeck coefficient S along the ab plane were systematically changed with oxygen contents and a power factor was consequently enhanced up to 3.5×10--6 Wcm-1K-2 at 300K for the sample annealed at 500°C in air. Moreover, the magnetic properties also showed a systematic change with oxygen contents.

We report preparation and thermoelectric properties of c-axis aligned and densified Ca3Co4O9 and [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 polycrystals. The c-axis alignment and densification were accomplished by magnetic alignment and spark plasma sintering methods, respectively. The obtained samples showed high degrees of c-axis orientation and relative densities, which were close to those of single crystals, resulting in the highest values of power factors in Ca3Co4O9 and [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 polycrystals.

The effect of the doping on the growth and superconducting properties of whiskers in the Bi–Sr–Ca–Cu–X–O system (where X = Na, B, Ga, and Pb, respectively), prepared by heating a glassy melt-quenched plate in flowing oxygen, is reported. The thermal behavior of the glassy samples (studied by DTA, XRD, and SEM techniques) was found to be dependent on the dopant as well as on its concentration. The Bi2Sr2CaCu2Ox (2212 phase) whiskers were grown only from the Ga-doped system annealed at 855 °C. The dependence of the mechanism of the whiskers' growth on the dopant is also discussed.