Sodalite‐type Cu‐based Three‐dimensional Metal–Organic Framework for Efficient Oxygen Reduction Reaction

Inspired by copper‐based oxygen reduction biocatalysts, we have studied the electrocatalytic behavior of a Cu‐based MOF (Cu‐BTT) for oxygen reduction reaction (ORR) in alkaline medium. This catalyst reduces the oxygen at the onset (E_onset) and half‐wave potential (E^1/2) of 0. 940 V and 0.778 V, respectively. The high halfway potential supports the good activity of Cu‐BTT MOF. The high ORR catalytic activity can be interpreted by the presence of nitrogen‐rich ligand (tetrazole) and the generation of nascent copper(I) during the reaction. In addition to the excellent activity, Cu‐BTT MOF showed exceptional stability too, which was confirmed through chronoamperometry study, where current was unchanged up to 12 h. Further, the 4‐electrons transfer of ORR kinetics was confirmed by hydrodynamic voltammetry. The oxygen active center namely copper(I) generation during ORR has been understood by the reduction peak in cyclic voltammetry as well in the XPS analysis.     

Code Optimization Techniques in Embedded DSP Microprocessors

We address the problem of code optimization for embedded DSP microprocessors. Such processors (e.g., those in the TMS320 series) have highly irregular datapaths, and conventional code generation methods typically result in inefficient code. In this paper we formulate and solve some optimization problems that arise in code generation for processors with irregular datapaths. In addition to instruction scheduling and register allocation, we also formulate the accumulator spilling and mode selection problems that arise in DSP microprocessors. We present optimal and heuristic algorithms that determine an instruction schedule simultaneously optimizing accumulator spilling and mode selection. Experimental results are presented.     

Power estimation methods for sequential logic circuits

Recently developed methods for power estimation have primarily focused on combinational logic. We present a framework for the efficient and accurate estimation of average power dissipation in sequential circuits. Switching activity is the primary cause of power dissipation in CMOS circuits. Accurate switching activity estimation for sequential circuits is considerably more difficult than that for combinational circuits, because the probability of the circuit being in each of its possible states has to be calculated. The Chapman-Kolmogorov equations can be used to compute the exact state probabilities in steady state. However, this method requires the solution of a linear system of equations of size 2^N where N is the number of flip-flops in the machine. We describe a comprehensive framework for exact and approximate switching activity estimation in a sequential circuit. The basic computation step is the solution of a nonlinear system of equations which is derived directly from a logic realization of the sequential machine. Increasing the number of variables or the number of equations in the system results in increased accuracy. For a wide variety of examples, we show that the approximation scheme is within 1-3% of the exact method, but is orders of magnitude faster for large circuits. Previous sequential switching activity estimation methods can have significantly greater inaccuracies     

CURE CHARACTERISTICS OF HYDROXYL TERMINATED POLYBUTADIENE PREPOLYMER WITH BLOCKED TOLUENE DIISOCYANATE-Ⅱ

Cure characteristics of hydroxyl terminated polybutadiene (HTPB) prepolymer with avariety of blocked toluene diisocyanate (TDI) in the presence of triethylamine (TEA) andchloroacetic acid catalyst are reported. Phenol, thiophenol, p-chloropheno1, p-nitrophenol,p-cresol, resorcinol, naphthols, caprolactam and butylated-hydroxytoluene were used as blockingagents. Viscosity measurements have been carried out using a mixture of HTPB and blocked TDIin cyclohexanone in the presence of the catalysts at 50℃ and 60℃ using Haake rotational vis-cometer. Viscosity measurements have also been carried out with 50% solids such as ammonium sulphate along with HTPB and TDI adduct.     

Hypergraphs with cyclomatic number zero,triangulated graphs,and an inequality

A parameter μ for hypergraphs generalizing the cyclomatic number of graphs is defined. Theorem: a hypergraph has μ = 0 if and only if its edges maximal with respect to inclusion are the cliques of a triangulated graph. The equality μ = 0 immediately implies an inequality previously proved by L. Lovász and by P. Hansen and M. Las Vergnas for more restricted classes of hypergraphs.     

A low power,low bandwidth protocol for remote wireless terminals

We present a low bandwidth protocol for wireless multimedia terminals targeted towards low power consumption on the terminal side. With the widespread use of portable computing devices, low power has become a major design criterion. One way of minimizing power consumption is to perform all tasks, other than managing hardware for the display and input, on a stationary workstation and exchange information between that workstation and the portable terminal via a wireless link. A protocol for such a system that emphasizes low bandwidth and low power requirements is presented herein. Such a protocol should address the issue of noisy wireless channels. We describe error correction and retransmission methods capable of dealing with burst error noise up to BERs of 10^-3. The final average bandwidth required is 140 Kbits/sec for 8bit color applications.     

Electrochemical Preparation of Yttrium Hexacyanoferrate on Reduced Graphene Oxide and Its Application to Analgesic Drug Sensor

Herein, we report a template free and surfactant less electrochemical approach for the preparation of flower‐like yttrium hexacyanoferrate (YHCF) particles on reduced graphene oxide (RGO) modified glassy carbon electrode (GCE). The morphology of YHCF particles has been controlled by varying the molar ratio of Y(NO₃)₂ and K₃Fe(CN)₆ for the first time. The surface morphology of as‐prepared RGO/YHCF composite was characterized using SEM, EDX, IR and XRD methods. The electrocatalytic activity of the RGO/YHCF composite modified GCE towards Paracetamol (PA) oxidation has been investigated by using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). Besides, the practical feasibility of the fabricated modified GCE has been demonstrated through the determination of PA from commercially purchased Paracetamol tablets.     

Hardware-software architecture of the SWAN Wireless ATM network

The SWAN (Seamless Wireless ATM Network) system provides end-to-end ATM connectivity to mobile end-points equipped with RF transceivers for wireless access. Users carrying laptops and multimedia terminals can seamlessly access multimedia data over a backbone wired network while roaming among room-sized cells that are equipped with basestations. The research focus on how to make ATM mobile and wireless distinguishes SWAN from present day mobile-IP based wireless LANs. This paper describes the design and implementation of the ATM-based wireless last-hop, the primary components of which are the air-interface control, the medium access control, and the low-level ATM transport and signalling.The design is made interesting by its interplay with ATM; in particular, by the need to meaningfully extend over the wireless last-hop the service quality guarantees made by the higher level ATM layers. The implementation, on the other hand, is an example of hardware-software co-design and partitioning. A key component of the wireless hop implementation is a custom designed reconfigurable wireless adapter card called FAWN (Flexible Adapter for Wireless Networking) which is used at the mobiles as well as at the basestations. The functionality is partitioned three-way amongst dedicated reconfigurable hardware on FAWN, embedded firmware on FAWN, and device driver software on a host processor. Using an off-the-shelf 625 Kbps per channel radio, several of which can be supported by a single FAWN adapter to provide multiple channels, per-channel unidirectional TCP data throughput of 227 Kbps (or, 454 Kbps bidirectional) and per-channel unidirectional native ATM data throughput of 210 Kbps (or, 420 Kbps bidirectional) have been obtained.     

Synthesis, spectral characterization and biological activities of Mn(II) and Co(II) complexes with benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone

Mn(II) and Co(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone have been synthesized and characterized by the investigations of electronic and EPR spectra and X-ray diffraction. Based on the spectral studies, an octahedral geometry is assigned for the Mn(II) and Co(II) complexes. X-ray powder diffraction studies reveal that Mn(II) and Co(II) complexes have triclinic crystal lattices. The unit cell parameters of the Mn(II) complex are a=11.0469 ?, b=6.2096 ?, c=7.4145 ?, α=90.646°, β=95.127°, γ=104.776°, V=489.7 ?(3) and those of Co(II) complex are a=9.3236 ?, b=10.2410 ?, c=7.8326 ?, α=90.694°, β=99.694°, γ=100.476°, V=724.2 ?(3). When the free ligand and its metal complexes are subjected to antibacterial activity, the metal complexes are proved to be more active than the ligand. However with regard to in vitro antioxidant activity, the ligand exhibits greater antioxidant activity than its metal(II) complexes.     

On the trade-off between energy efficiency and estimation error in compressive sensing

Compressive sensing (CS) refers to the process of reconstructing a signal that is supposed to be sparse or compressible. CS has wide applications, such as in cognitive radio networks. In this paper, we investigate effective CS schemes for the trade-off between energy efficiency and estimation error. We propose an enhancement to a Bayesian estimation approach and an enhancement to the isotonic regression approach that is based on nearly isotonic regression. We also show how to compute the routing matrix for selecting active sensor nodes. The proposed enhancements are evaluated with trace-driven simulations. Considerable gaps are observed between the original approaches and the proposed enhancements in the simulation results. The near isotonic regression method achieves the best performance among all the CS schemes examined in this paper.