LAN Bridge Research Articles

Rare-Earth Single-Atom La-N Charge-Transfer Bridge on Carbon Nitride for Highly Efficient and Selective Photocatalytic CO2 Reduction.

Photocatalytic CO2 conversion into valuable solar fuels is highly appealing, but lack of directional charge-transfer channel and insufficient active sites resulted in limited CO2 reduction efficiency and selectivity for most photocatalytic systems. Herein, we designed and fabricated rare-earth La single-atoms on carbon nitride with La-N charge-transfer bridge as the active center for photocatalytic CO2 reaction. The formation of La single-atoms was certified by spherical aberration-corrected HAADF-STEM, STEM-EELS, EXAFS, and theoretical calculations. The electronic structure of the La-N bridge enables a high CO-yielding rate of 92 μmol·g-1·h-1 and CO selectivity of 80.3%, which is superior to most g-C3N4-based photocatalytic CO2 reductions. The CO production rate remained nearly constant under light irradiation for five cycles of 20 h, indicating its stability. The closely combined experimental and DFT calculations clearly elucidated that the variety of electronic states induced by 4f and 5d orbitals of the La single atom and the p-d orbital hybridization of La-N atoms enabled the formation of charge-transfer channel. The La-N charge bridges are found to function as the key active center for CO2 activation, rapid COOH* formation, and CO desorption. The present work would provide a mechanistic understanding into the utilization of rare-earth single-atoms in photocatalysis for solar energy conversion.

VLSI Design and Implementation of Low Power PBCAM: A Tutorial and Survey

Background: A CAM is a fully parallel operating device. For high speed data searching functions CAM provides very efficient hardware architecture1. Statistical Analysis: This paper presents novel developments in the recent design of high capacity Content Addressable Memory (CAM) and Pre-computational Based CAM (PB-CAM). A graphical analysis has been shown between PB-CAM using static parameter circuit and proposed parameter circuit for power, delay and power-delay product in 90nm CMOS technology. Findings: There are many techniques made for designing a CAM by taking in mind to get lowpower, low-noise, high-speed, less hardware cost and less data comparisons and with minimum number of transistors and gates. There are, Traditional Dynamic CAM architecture, Ones-Count PB-CAM, Parity function PB-CAM, Remainder function PB-CAM, Block-XOR PB-CAM and Master–Slave Match Line (MSML) design. In this paper we have compared 9T and 7T CAM cell operations. Static parameter circuit is compared with proposed parameter comparison circuit for powerdelay product in 45nm CMOS technology. Applications: CAM function can be used in broader applications, such as data compression, LAN bridges, data comparison, switches, Lookup tables, Asynchronous Transfer Mode (ATM) switches, databases, communication devices, communication networks, tag directories and high speed Ethernet etc.

Utilization of Wireless LAN Bridge

Utilization of Wireless LAN Bridge

Nine Post-translational Modifications during the Biosynthesis of Cinnamycin

Lantibiotics are ribosomally synthesized and post-translationally modified antimicrobial peptides that are characterized by the thioether cross-linked amino acids lanthionine (Lan) and methyllanthionine (MeLan). Cinnamycin is a 19 amino acid lantibiotic that contains one Lan and two MeLan. Cinnamycin also contains an unusual lysinoalanine (Lal) bridge formed from the ε-amino group of lysine 19 and a serine residue at position 6, and an erythro-3-hydroxy-l-aspartic acid resulting from the hydroxylation of l-aspartate at position 15. These modifications are critical in mediating the interactions of cinnamycin with its target, phosphatidylethanolamine. Recently, the cinnamycin biosynthetic gene cluster (cin) from Streptomyces cinnamoneus cinnamoneus DSM 40005 was reported. Herein, we investigated the biosynthetic machinery using both in vitro studies and heterologous expression in Escherichia coli. CinX is an α-ketoglutarate/iron(II)-dependent hydroxylase that carries out the hydroxylation of aspartate 15 of the precursor peptide CinA. In addition, CinM catalyzes dehydration of four Ser and Thr residues and subsequent cyclization of Cys residues to form the three (Me)Lan bridges. The order of the post-translational modifications catalyzed by CinM and CinX is interchangeable in vitro. CinX did not require the leader sequence at the N-terminus of CinA for activity, but the leader peptide was necessary for CinM function. Although CinM dehydrated serine 6, it did not catalyze the formation of Lal. A small protein encoded by cinorf7 is critical for the formation of the cross-link between Lys19 and dehydroalanine 6 as shown by coexpression studies of CinA, CinM, CinX, and Cinorf7 in E. coli.

Design, implementation and performance analysis of the CAN/ATM local bridge

In this paper, a method describing connection between CAN and ATM systems is presented. 1 1 This paper is a combined, updated and extended revision of [I. Ozcelik, I. Erturk, H. Ekiz, F. Selçuk, Design and Implementation of a CAN/ATM LAN Bridge, Proceedings of the ELECO, pp 256–260, 7–11 November 2001, Bursa, Turkey.; I. Ozcelik, I. Ertürk, H. Ekiz, F. Selçuk, Performance Analysis of a CAN/ATM LAN Bridge Under Various Loads, CS&I 2002, pp 314–318, 8–14 March, 2002, Durham, NC, USA] studies. The proposed method reveals the usage of ATM at the cell level of the CIM architecture. This leads to the fact that a new bridge based on CAN and ATM features should be designed. The new bridge is called as CAN/ATM Local Bridge. This study is concerned with not only CAN and ATM interconnection requiring worst-case translation but also the performance analysis of the model provided CACI Network II.5.

The HALO network/sup TM/

The High Altitude Long Operation Network/sup TM/ is a broadband wireless metropolitan area network, with a star topology, whose solitary hub is located in the atmosphere above the service area at an altitude higher than commercial airline traffic. The HALO/Proteus airplane is the central node of this network. It will fly at altitudes higher than 51,000 ft. The signal footprint of the network, its "Cone of Commerce", will have a diameter on the scale of 100 km. The initial capacity of the network will be on the scale of 10 Gb/s, with growth beyond 100 Gb/s. The network will serve the communications needs of each subscriber with bit rates in the multimegabit per second range. A variety of spectrum bands licensed by the FCC for commercial wireless services could provide the needed millimeter wavelength carrier bandwidth. An attractive choice for the subscriber links is the LMDS band. The airplane's fuselage can house switching circuitry and fast digital network functions. An MMW antenna array and its related components will be located in a pod suspended below the aircraft fuselage. The antenna array will produce many beams, typically more than 100. Adjacent beams will be separated in frequency. Electronic beamforming techniques can be used to stabilize the beams on the ground, as the airplane flies within its station keeping volume. For the alternative of aircraft-fixed beams, the beams will traverse over a user location, while the airplane maintains station overhead, and the virtual path will be changed to accomplish the beam-to-beam handoff. For each isolated city to be served, a fleet of three aircraft will be operated in shifts to achieve around-the-clock service. In deployments where multiple cities will be served from a common primary flight base, the fleet will be sized for allocating, on average, two aircraft per city to be served. Flight operational tactics will be steadily evolved and refined to achieve continuous presence of the node above each city. Many services will be provided, including but not limited to T1 access, ISDN access, Web browsing, high-resolution videoconferencing, large file transfers, and Ethernet LAN bridging.

100Base-T/IEEE 802.12/packet switching

Three LAN technologies look set to satisfy the ever-increasing demand for LAN bandwidth. Two of these technologies are 100 Mb/s shared-medium LANs: 100Base-T (aka IEEE 802.3 Fast Ethernet) and IEEE 802.12 (aka 100VG-AnyLAN or 100VG). The third technology is packet switching, which is really an extension of existing LAN bridge technology, but offers excellent performance gains at very low cost. The authors describe the three technologies and provide a comparison between the two 100 Mb/s LANs. Also presented are results that compare the measured performance of 100 Mb/s shared-medium LANs with switched LANs.

The IBM 8209 LAN bridge

The issues involved in bridging 802.5 (token-ring) and 802.3 (Ethernet) networks at the media access control (MAC) layer are discussed. The issues concern incompatibilities between the two networks in six areas: routing schemes, station addresses, frame formats, and local area network speeds. An approach incorporated in the IBM 8209 LAN bridge for resolving the incompatibilities is described. The IBM 8209 LAN bridge, a two-port MAC bridge, supports source routing on the token ring/802.5 side and transparent bridging on the Ethernet/802.3 side. Recently proposed changes in the token-ring source routing standards are discussed. >

Some experience with LAN interconnection via frame relaying

Recent work on new ISDN packet-mode services has shown that frame relaying is particularly well-suited to the task of connecting remote bridges between physically distant local area networks. The authors summarize their experience gained through the building and trial use of a bridge that interconnects token rings by means of frame relaying. They conclude that frame relaying provides a balance between functionality and speed that is very well suited to the needs of LAN bridges for wide area network (WAN) connectivity. The access line rates can be significantly higher that is often conventionally cost effective. These speeds can be effectively utilized because of the very low protocol overheads, and they are cost effective because they can be shared among many logical connections. >

Local area network bridges

In this paper the authors describe local area network bridges and how they may be used to link networks. The functionality and the relative advantages and disadvantages of LAN bridges, compared to other network interconnection methods, are discussed. An alternative source routing bridge for token ring networks is also outlined.