The BaO-BaO 2 reaction cycle was investigated in a range of temperatures from 973 to 1123 K and oxygen pressures from 0 to 0.2 MPa using the BaO 2 -MgO oxygen acceptor of different barium content and sample size prepared with barium peroxide and magnesium oxide. The rates of the oxidation of barium oxide and the reduction of barium peroxide by the BaO 2 -MgO oxygen acceptor during repeated cycling were little influenced by pellet sizes smaller than 16 mm in diameter, and an increase in the barium content of the sample led to a decrease in the reaction rate, while oxygen loading of the oxygen acceptor increased. In addition, fairly high reaction rates were obtained for the BaO 2 /MgO at ratios up to 1:1.4 (mol). The application of the BaO-BaO 2 reaction cycle to oxygen production or enrichment with regard to operation mode and conditions was also investigated using the BaO 2 -MgO oxygen acceptor.

Nanowire (NW) structures are being extensively investigated as components for energy devices such as solar cells [1] and batteries [2]. The large aspect ratio of NWs makes them ideal candidates for maximizing surface reactions, minimizing carrier transport distances, fabricating semi-transparent contact layers, and other device optimization pathways. Although methods for growing NWs are well established, and much current research is focused on device fabrication and characterization, much remains unknown about fundamental aspects of the nucleation and growth mechanisms, and the effect of such parameters as different substrates and catalysts. The work presented here focuses on the growth and microstructure of Ge and PbSe NWs. Ge NWs, while not a prime candidate for single-component solar cells, offer interesting opportunities for lattice matching in multijunction devices and as templates for novel architectures. Epitaxial Ge NWs are readily grown at low temperatures on Si substrates [3], so are easily integrated into current fabrication processes. PbSe is of interest for multi-exciton generation (MEG) devices and solar cells with PbSe quantum dots have been demonstrated. However, NWs provide a better morphology for building connected structures.Epitaxial Ge NWs grow vertically on (111) Ge or Si substrates, with Au nanoparticles acting as a catalyst [3]. However the NW yield and size distribution is consistently better on Ge than on Si. We have found that using porous Si as the substrate also improves the yield and uniformity; SIMS and EDS data show Ge and Au diffusion into the porous substrate (Fig.1). Cross-section TEM indicates that formation of the ternary eutectic phase at the substrate competes with binary phase melting at the Au surface, leading to embedded rather than vertical NWs (Fig.2). Porous Si diminishes this effect by diverting the ternary phase into the pores. Concomitantly, the greatly enhanced surface area provided by the pores (estimated as 900X) prevents Au nanoparticle coarsening and breakup, also leading to improved NW yield and uniformity.We observe both VLS (vapor-liquid-solid) and dislocation-mediated growth in PbSe NWs synthesized during the same processing run [4]. PbSe has a rocksalt structure and the NWs grow in the [001] direction, exhibiting secondary branching in the [100/010] directions as catalysts redeposit on the NW. Some of the NWs propagate via a screw dislocation down the center of the wire, exhibiting chiral structures observed in SEM as a rotating branch structure (Fig. 3.) Two-beam imaging confirms that the dislocation has pure screw character. The chirality is caused by the elastic strain of the axial screw dislocation, which produces a corresponding Eshelby Twist.

Carambola wuluh is one of Indonesia’s natural resources that is still less optimized in its utilization. Generally, people use Carambola wuluh only to be processed into sunti acid which is then used as a flavor enhancer in cooking. The content of oxalic acid in sunti acid can be utilized as a raw material for the gel electrolyte which will be used to recharge used batteries. This study aims to determine the potential of sunti acid extract for the recharging process of used batteries. The voltage obtained from the electrolyte gel of the sunti extract is greater when compared to the accuser voltage. The results showed that the best compositions for obtaining the optimum voltage and current strength was 7% (w / v), NaCl 1.25% (w / v) and Glycerol 40% (v / v) for the electrolyte gel and addition of 10% NaOH 1M and 0.01% KMnO4, based on the volume of the electrolyte gel, to increase the voltage and the strength of the resulting current. The results obtained are expected not only to turn on the LED lights and the motor drive (dynamo), but also be an alternative material for recharging used batteries.