Construction of vertex-disjoint paths in alternating group networks

The existence of parallel node-disjoint paths between any pair of nodes is a desirable property of interconnection networks, because such paths allow tolerance to node and/or link failures along some of the paths, without causing disconnection. Additionally, node-disjoint paths support high-throughput communication via the concurrent transmission of parts of a message. We characterize maximum-sized families of parallel paths between any two nodes of alternating group networks. More specifically, we establish that in a given alternating group network AN _n , there exist n−1 parallel paths (the maximum possible, given the node degree of n−1) between any pair of nodes. Furthermore, we demonstrate that these parallel paths are optimal or near-optimal, in the sense of their lengths exceeding the internode distance by no more than four. We also show that the wide diameter of AN _n is at most one unit greater than the known lower bound D+1, where D is the network diameter.     

Weighted two-valued digit-set encodings: unifying efficient hardware representation schemes for redundant number systems

We introduce the notion of two-valued digit (twit) as a binary variable that can assume one of two different integer values. Posibits, or simply bits, in {0,1} and negabits in {-1,0}, commonly used in two's-complement representations and (n,p) encoding of binary signed digits, are special cases of twits. A weighted bit-set (WBS) encoding, which generalizes the two's-complement encoding by allowing one or more posibits and/or negabits in each radix-2 position, has been shown to unify many efficient implementations of redundant number systems. A collection of equally weighted twits, including ones with noncontiguous values (e.g., {-1,1} or {0,2}), can lead to wider representation range without the added storage and interconnection costs associated with multivalued digit sets. We present weighted twit-set (WTS) encodings as a generalization of WBS encodings, examine key properties of this new class of encodings, and show that any redundant number system (e.g., generalized signed-digit and hybrid-redundant systems), including those that are based on noncontiguous and/or zero-excluded digit sets, is faithfully representable by WTS encoding. We highlight this broad coverage by a tree chart having WTS representations at its root and various useful redundant representations at its many internal nodes and leaves. We further examine how highly optimized conventional components such as standard full/half-adders and compressors may be used for arithmetic on WTS-encoded operands, thus allowing highly efficient and VLSI-friendly circuit implementations. For example, focusing on the WBS-like subclass of WTS encodings, we describe a twit-based implementation of a particular stored-transfer representation which offers area and speed advantages over other similar designs based on WBS and hybrid-redundant representations.     

Bimetallic PtPd nanoparticles relying on CoNiO2 and reduced graphene oxide as a most operative electrocatalyst toward ethanol fuel oxidation

Of late, fuel cells have drawn great attentions owing to high-energy demands, fossil fuel depletion and worldwide environmental pollution. Direct ethanol fuel cell (DEFC) constituted as one of the most promising sources of green energy, howbeit the ethanol oxidation reaction (EOR) sluggish kinetic is one of the essential challenges toward the commercialization of DEFCs. Herein, we introduce bimetallic catalyst on CoNiO₂ modified reduced graphene oxide (rGO) to completely exploit the advantages of nano-surface structures as well as the reduction of Pt and Pd loading in fuel cells. With the combined advantages of PtPd, CoNiO₂ and rGO, a significant enhancement in electrocatalytic behavior, stability and CO poisoning tolerance of PtPd have been observed. Regarding the implications, PtPd/CoNiO₂/rGO is greatly preferable than Pt/CoNiO₂/rGO and Pd/CoNiO₂/rGO in terms of high electroactive surface area (ECSA), electro-catalytic activity, and lower onset potential (E_ons) towards the EtOH oxidation in alkaline media. Furthermore, the chronoamperometry curve (CA) illustrated 77% after 3600 s which is dramatically soared compared with the other electrodes (≤40%), demonstrating the high stability of the PtPd bimetallic nanoparticle electrocatalyst. Ultimately, PtPd/CoNiO₂/rGO nanocomposite is found to be an excellent anode electrocatalyst for application in DEFCs.     

Platinum–Iron nanoparticles supported on reduced graphene oxide as an improved catalyst for methanol electro oxidation

Platinum–Iron nanoparticles supported on reduced graphene oxide powder are synthesized by chemical reduction method as an anode catalyst for the methanol electro oxidation. The characterization of the catalyst has been investigated using physical and electrochemical methods. Prepared catalyst was characterized by scanning electron microscopy (SEM), TEM (Transmission electron microscopy), FT-IR (Fourier-transform infrared spectroscopy), Raman spectroscopy and, X-ray diffraction (XRD) and energy dispersive analysis of X-ray (EDX). Pt and Pt-Fe nanoparticles are uniformly dispersed on the surface of reduced graphene oxide (rGO) powder nanocomposite support. The catalytic properties of the catalyst for methanol electro-oxidation were thoroughly studied by electrochemical methods that involved in the cyclic voltammetry, linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The Pt-Fe/rGo exhibits high electrocatalytic activity, catalyst tolerance for the CO poisoning and catalyst durability for electro-oxidation of methanol compared to the Pt/rGo and commercial Pt/C catalyst. Therefore, the Pt-Fe/rGo catalyst is a good choice for application in direct methanol fuel cells.     

DIRECT ELECTROCHEMICAL POWER GENERATION FROM CARBON IN FUEL CELLS WITH MOLTEN HYDROXIDE ELECTROLYTE

Historically, despite its compelling cost and performance advantages, the use of a molten metal hydroxide electrolyte has been ignored by direct carbon fuel cell (DCFC) researchers, primarily due to the potential for formation of carbonate salt in the cell. This article describes the electrochemistry of a patented medium-temperature DCFC based on a molten hydroxide electrolyte, which overcomes the historical carbonate formation.

An important technique discovered for significantly reducing carbonate formation in the DCFC is to ensure a high water content of the electrolyte. To date, four successive generations of DCFC prototypes have been built and tested to demonstrate the technology – all using graphite rods as their fuel source. These cells all used a simple design in which the cell containers served as the air cathodes and successfully demonstrated the ability to deliver more than 40 A with the current density exceeding 250 mA/cm². Conversion efficiency greater than 60% was achieved.     

Oxy210, a Semi-Synthetic Oxysterol,Exerts Anti-Inflammatory Effects in Macrophages via Inhibition of Toll-like Receptor (TLR) 4 and TLR2 Signaling and Modulation of Macrophage Polarization

Inflammatory responses by the innate and adaptive immune systems protect against infections and are essential to health and survival. Many diseases including atherosclerosis, osteoarthritis, rheumatoid arthritis, psoriasis, and obesity involve persistent chronic inflammation. Currently available anti-inflammatory agents, including non-steroidal anti-inflammatory drugs, steroids, and biologics, are often unsafe for chronic use due to adverse effects. The development of effective non-toxic anti-inflammatory agents for chronic use remains an important research arena. We previously reported that oral administration of Oxy210, a semi-synthetic oxysterol, ameliorates non-alcoholic steatohepatitis (NASH) induced by a high-fat diet in APOE*3-Leiden.CETP humanized mouse model of NASH and inhibits expression of hepatic and circulating levels of inflammatory cytokines. Here, we show that Oxy210 also inhibits diet-induced white adipose tissue inflammation in APOE*3-Leiden.CETP mice, evidenced by the inhibition of adipose tissue expression of IL-6, MCP-1, and CD68 macrophage marker. Oxy210 and related analogs exhibit anti-inflammatory effects in macrophages treated with lipopolysaccharide in vitro, mediated through inhibition of toll-like receptor 4 (TLR4), TLR2, and AP-1 signaling, independent of cyclooxygenase enzymes or steroid receptors. The anti-inflammatory effects of Oxy210 are correlated with the inhibition of macrophage polarization. We propose that Oxy210 and its structural analogs may be attractive candidates for future therapeutic development for targeting inflammatory diseases.     

Synthesis of Clay/Poly (styrene/2-ethylhexyl acrylate) Nanocomposite Latexes via Emulsion Polymerization

Silicon - In this research, nanocomposite latex based on polystyrene-co-2-ethylhexyl acrylate with layered silicate was synthesized by emulsion polymerization procedure. For increasing...