Electrochemical studies of zirconium and hafnium in alkali chloride and alkali fluoride-chloride molten salts

The electrochemical reduction of zirconium and hafnium in alkali chloride or fluoride-chloride molten salts on platinum electrodes has been investigated by means of linear and cyclic voltammetry. It has been found that fluoride ions greatly influenced the reduction of zirconium and hafnium in fluoride-chloride melts. It has been proposed that the mechanism for reduction of zirconium and hafnium in baths containing a low concentration of fluoride compounds is different from the mechanism in baths containing a higher fluoride concentration.     

Development of quasi-end-fired waveguide plastic dye laser

A quasi-end-fire (QEF) pumping scheme was proposed and studied as a novel laser-pumping-scheme for a laser-dye-doped plastic waveguide laser with distributed feedback. This pumping scheme resembled longitudinal pumping, but also has the advantage of controllable absorption length of the injected pump beam. A first demonstration of the QEF was performed and the pumping beam controlling was also investigated.     

Multiple-availability-level ATM network architecture

Because of their high flexibility, ATM networks have the potential to achieve two objectives: switch cost reduction and multi-level network availability. For that purpose, this article proposes to use virtual circuit (VC) route self-healing schemes to achieve a multiple-availability-level ATM network. Flexible multi-QoS logical ATM network (Full-Net), a new concept for ATM networks, is now being studied at NTT Laboratories. Full-Net is a very flexible network design strategy for survivable networks that is based on a self-healing VC network. Defining several logical configurations of the VC network allows us to support multiple levels of network availability, simplifies the adaptation to future and unknown service requirements, and significantly reduces overall ATM network cost. Offering different levels of availability not only saves the network's resources, but also allows the network operator to provide its customers with services at the most appropriate cost. We introduce the advantages of VC route restoration for ATM networks, and compare virtual path (VP) level and physical level restoration strategies. We explain Full-Net's concept, propose a VC route self-healing scheme, and show the impact of the logical network configurations on network survivability and resource management     

A 10-Gb/s (1.25 Gb/s×8)4×2 0.25-μm CMOS/SIMOX ATMswitch based on scalable distributed arbitration

This paper presents the design and implementation of a scalable asynchronous transfer mode switch. We fabricated a 10-Gb/s 4×2 switch large-scale integration (LSI) that uses a new distributed contention control technique that allows the switch LSI to be expanded. The developed contention control is executed in a distributed manner at each switch LSI, and the contention control time does not depend on the number of connected switch LSI's. To increase the LSI throughput and reduce the power consumption, we used 0.25-μm CMOS/SIMOX (separation by implanted oxygen) technology, which enables us to make 221 pseudo-emitter-coupled-logic I/O pins with 1.25-Gb/s throughput. In addition, power consumption of 7 W is achieved by operating the CMOS/SIMOX gates at -2.0 V. This consumption is 36% less than that of bulk CMOS gates (11 W) at the same speed at -2.5 V. Using these switch LSI's, an 8×8 switching multichip module with 80-Gb/s throughput was fabricated with a compact size     

Scalable 10 Gbit/s 4×20.25 μm CMOS/SIMOX ATM switch LSIcircuit based on distributed contention control

A scalable 10 Gbit/s 4×2 ATM switch LSI circuit has been fabricated. It employs a new distributed contention control technique that makes the LSI circuit expandable. To increase the LSI circuit throughput, 0.2 μm CMOS/SIMOX (separation by implanted oxygen) technology is used. It allows the LSI circuit to offer 221 I/O pins, an operating speed of 1.25 Gbit/s and 7 W power consumption     

Concurrent fault detection for a multiple-plane packet switch

In high-speed and high-capacity packet switches, system reliability is critical to avoid loss of huge amounts of information and retransmission of traffic. We propose a series of concurrent fault-detection mechanisms for a multiple-plane crossbar-based packet switch. Our switch model, called the m+z model, has m active planes and z spare planes. This switch has distributed arbiters on each plane. The spare planes, used for substitution of faulty active ones, are also used in the fault-detection mechanism, thus providing fault detection and fault location for all switching planes. Our detection schemes are able to detect a single fault quickly without increasing transmission overhead. The proposed schemes can be used for switches with different numbers of active planes and a small number of spare planes.     

Lactic acid bacteria isolated from ethnic preserved meat products of the Western Himalayas

We used culture- and molecular-biology-based methods to investigate the diversity of lactic acid bacteria (LAB) in the ethnic chevon (goat) meat products chartayshya, jamma and arjia of the Western Himalayas. In six chartayshya, six jamma and four arjia samples, LAB were the predominant microbial component involved in the fermentation of these samples, and the total LAB population in arjia (7.8 ± 0.1 log cfu g⁻¹; mean ± SD) was significantly higher (P < 0.05) than in chartayshya (6.9 ± 0.1 log cfu g⁻¹) and jamma (7.5 ± 0.1 log cfu g⁻¹). We identified 53 LAB samples by 16S rRNA and phenylalanyl-tRNA synthase (pheS) genes sequencing. The LAB isolates were identified as Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Leuconostoc citreum, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria. These results revealed that there is a high level of diversity of LAB in the Himalayan ethnic preserved meat products.     

A New Lead Identification Strategy: Screening an sp3-rich and Lead-like Compound Library Composed of 7-Azanorbornane Derivatives

Although the advantages of sp³-rich, sterically complicated molecules in drug development have been pointed out, modern screening libraries are filled with planar, sp²-rich components. Compounds that are sp³-rich are difficult to synthesize, and thus we aimed to invent an efficient method to construct sp³-rich libraries. By modifying sp³-rich 7-azanorbornane scaffolds through click chemistry, we efficiently prepared a small set of compounds. These compounds were not only sp³-rich, but also had sufficient “lead-like” properties in view of molecular weights and hydrophobicity. Screening assays of this library provided weak κ opioid receptor agonists and growth hormone secretagogue receptor agonists with high hit rates. These results indicate that the 7-azanorbornane scaffold may be a “privileged structure” for lead identification in drug discovery.     

Effects of metal support interaction on dry reforming of methane over Ni/Ce-Al2O3 catalysts

Dry (CO₂) reforming of methane is conducted over two newly synthesized Ni20/Ce-γAl₂O₃ and Ni20/Ce-meso-Al₂O₃ catalysts. The x-ray diffraction (XRD) patterns indicated that Ni20/Ce-meso-Al₂O₃ exhibits a better dispersion of nickel, while Ni20/Ce-γAl₂O₃ has larger amounts of nickel crystallites. The temperature programmed desorption (TPD) kinetics analysis indicated that Ni20/Ce-meso-Al₂O₃ had a lesser metal-support interaction than the Ni20/Ce-γAl₂O₃. The thermal gravimetric analysis (TGA) indicated that the incorporation of ceria into the Al₂O₃ matrix helps to stabilize Ni20/Ce-meso-Al₂O₃ during dry reforming of methane. The temperature programmed reduction (TPR) indicated that the synthesized catalysts were sufficiently reducible below 750 °C. A fixed bed reactor evaluation (at 750 °C) showed that both catalysts can facilitate methane reforming to syngas with minimal coking throughout the 30 hours time-on-stream (TOS). However, Ni20/Ce-meso-Al₂O₃ is more promising in terms of prolonged stability for dry reforming applications. Moreover, the syngas yield for Ni20/Ce-γAl₂O₃ is close to equilibrium prediction during the first 1 hour of reaction time.     

[4.3.1]Bicyclic FKBP Ligands Inhibit Legionella Pneumophila Infection by LpMip-Dependent and LpMip-Independent Mechanisms**

Legionella pneumophila is the causative agent of Legionnaires’ disease, a serious form of pneumonia. Its macrophage infectivity potentiator (Mip), a member of a highly conserved family of FK506-binding proteins (FKBPs), plays a major role in the proliferation of the gram-negative bacterium in host organisms. In this work, we test our library of >1000 FKBP-focused ligands for inhibition of LpMip. The [4.3.1]-bicyclic sulfonamide turned out as a highly preferred scaffold and provided the most potent LpMip inhibitors known so far. Selected compounds were non-toxic to human cells, displayed antibacterial activity and block bacterial proliferation in cellular infection-assays as well as infectivity in human lung tissue explants. The results confirm [4.3.1]-bicyclic sulfonamides as anti-legionellal agents, although their anti-infective properties cannot be explained by inhibition of LpMip alone.