A brief review of the ionic conductivity enhancement for selected oxide electrolytes

The advantages of lowering the operation temperature of SOFCs have attracted great interest worldwide. One of the major barriers to decreasing the operation temperature is the ohmic loss of the electrolyte. Maximizing the electrolyte ionic conductivity is of significant importance, especially in the absence of new electrolyte materials. The ionic conductivity of electrolytes can be influenced by many parameters. There has been an enormous effort in the literature for the improvement of the electrolyte ionic conductivity. From a practical point of view, this paper reviews various approaches to enhancing the ionic conductivity of polycrystalline zirconia- and ceria-based oxide electrolytes in the light of composition, microstructure, and processing. Suggestions are given for future work.     

Cooperative multihop broadcast for wireless networks

We address the minimum-energy broadcast problem under the assumption that nodes beyond the nominal range of a transmitter can collect the energy of unreliably received overheard signals. As a message is forwarded through the network, a node will have multiple opportunities to reliably receive the message by collecting energy during each retransmission. We refer to this cooperative strategy as accumulative broadcast. We seek to employ accumulative broadcast in a large scale loosely synchronized, low-power network. Therefore, we focus on distributed network layer approaches for accumulative broadcast in which loosely synchronized nodes use only local information. To further simplify the system architecture, we assume that nodes forward only reliably decoded messages. Under these assumptions, we formulate the minimum-energy accumulative broadcast problem. We present a solution employing two subproblems. First, we identify the ordering in which nodes should transmit. Second, we determine the optimum power levels for that ordering. While the second subproblem can be solved by means of linear programming, the ordering subproblem is found to be NP-complete. We devise a heuristic algorithm to find a good ordering. Simulation results show the performance of the algorithm to be close to optimum and a significant improvement over the well known BIP algorithm for constructing energy-efficient broadcast trees. We then formulate a distributed version of the accumulative broadcast algorithm that uses only local information at the nodes and has performance close to its centralized counterpart.     

Remodeling of chromatin loops does not account for specification of replication origins during Xenopus development

The right mammary gland of 12 lactating goats was inoculated intracisternally with 1 ml of Mycoplasma capricolum subsp. capripneumoniae (Mcc) containing 10(6) colony-forming units (CFU), while their left mammary halves received 1 ml of sterile PPLO broth only. Two goats served as uninfected controls. The clinical mastitis that developed in the infected mammary halves within 24 h was initially acute but became increasingly chronic by the end of the experiment at 24 days post inoculation (DPI). The disease was characterized by atrophy of the infected mammary halves, leading to marked agalactia and an increase in somatic cell counts, with a preponderance of neutrophils initially and lymphocytes later. The Mycoplasma was re-isolated from infected mammary secretions up to 16 DPI but not from blood. Histopathology revealed that the mastitis was acute and purulent initially, followed by infiltration of lymphonuclear cells and fibroplasia in the lymphomononuclear cells and fibroplasia in the interacinar tissue, and later by massive fibrosis. Immunohistology demonstrated the presence of Mycoplasma-like bodies localized mainly on the surface of acinar/duct epithelial cells. The studies showed that Mcc was highly pathogenic in the caprine mammary gland.     

Discovery of New Antiproliferative Imidazopyrazole Acylhydrazones Able To Interact with Microtubule Systems

Even though immunotherapy has radically changed the search for anticancer therapies, there are still many different pathways that are open to intervention with traditional small molecules. To expand our investigation in the anticancer field, we report here a new series of compounds in which our previous pyrazole and imidazopyrazole scaffolds are linked to a differently decorated phenyl ring through an acylhydrazone linker. Preliminary tests on the library were performed at the National Cancer Institute (USA) against the full NCI 60 cell panel. The best compounds among the imidazopyrazole series were then tested by immunofluorescence staining for their inhibition of cell proliferation, apoptosis induction, and their effect on the cell cycle and on microtubules. Two compounds, in particular 4-benzyloxy-3-methoxybenzyliden imidazopyrazole-7-carbohydrazide showed good growth inhibition, with IC₅₀ values in the low-micromolar range, and induced apoptosis. Both compounds altered the cell-cycle phases with the appearance of polyploid cells. Immunofluorescence analysis evidenced microtubules alterations; tubulin polymerization assays and docking studies suggested the tubulin system to be the possible, although not exclusive, target of the new acylhydrazone series reported here.     

A new family of frequency-hop codes

We give an algebraic construction for a new family of frequency-hop codes. The construction is based on properties of finite fields: it is shown that for each field GF(p^m), there exists a large number of codes of length p^m. The codes are also shown to possess the best possible simultaneous two-dimensional autocorrelation and cross-correlation properties. Moreover, they include a family of codes: with a code length of a power of 2, which are ideally suitable for applications in digital communication systems     

Powder prepared by spray pyrolysis as an electrode material for solid oxide fuel cells

A variety of spray pyrolysis (SP) techniques have been developed to directly produce ceramic powders from solutions. Examples that are discussed include the following powders: (La_0.8Sr_0.2)_0.9MnO₃-YSZ (La(Sr)MnO₃-YSZ), La_0.6Sr_0.4CoO₃ (La(Sr)CoO₃), (CeO₂)_0.8(SmO_1.5)_0.2-NiO (SDC-NiO) and La_0.9Sr_0.1Ga_0.8Mg_0.2O₃-NiO (LSGM-NiO). For all these powders, spherical, non-agglomerated, submicrometer particles were obtained from aqueous solution of metal salts into a furnace using an ultrasonic atomizer at 1.7 MHz. After SP some of the particles exhibit a hollow-shell morphology. Subsequent calcination at 1000°C yielded crystalline particles. The electrical performance of Ni-SDC/LSGM/La(Sr)CoO₃ fuel cells operating at 800°C, prepared from the powders obtained by SP, is reported.     

Automatic digital correction of measurement data based onM-point autocalibration and inverse polynomial approximation

A microprocessor-controlled measurement system model comprising m-point autocalibration and inverse polynomial approximation of the measurement-system transfer characteristics is described. A voltage-to-frequency converter is used for an analog-to-digital conversion of an input quantity. The model is restricted to measurements of slow-varying analog input quantities, and it is suitable for application in severe temperature conditions, common to a variety of industrial environments. By utilizing the computing power of microprocessors, a higher accuracy of measurements can be achieved with low-performance electronic components