Graphene/Ni–Fe layered double hydroxide nano composites as advanced electrode materials for glucose electro oxidation

NickelIron Layered Double Hydroxide nano composites were electrochemically synthesized on graphene/glassy carbon electrode at a constant potential. The surface morphology and the structure of the electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), elemental mapping analysis, X-ray diffraction (XRD) and Atomic force microscopy (AFM). This electrode was studied for glucose electro-oxidation reaction using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy (EIS) techniques. Results confirmed high catalytic activity, stability of the graphene/NiFe LDH electrode and glucose electro oxidation reaction on this electrode is under the effect of diffusion process. Also in comparison of some previous reported methods for the glucose electro oxidation, graphene/NiFe LDH shows a high diffusion coefficient as an electro catalyst for glucose electro oxidation. Electrical equivalent circuits for electrodes is obtained by using the Zview software. The low electrochemical charge transfer resistance (R_ct) was obtained on the graphene/NiFe LDH due to the presence of NiFe LDH nano composite.     

Puzzling Problems in Computer Engineering

University faculty have designed an engaging puzzle-based freshman seminar intended to motivate and retain computer engineering students.     

Scalability of Programmable FIR Digital Filters

Previous designs of programmable FIR digital filters have demonstrated that the use of broadcast data and control can lead to a high performance-to-cost ratio. As the technology advances to the deep sub-micrometer regime, such an approach should be re-examined by taking the effect of interconnections into account. In this paper, we show that the contribution of interconnect delay to the cycle time is no longer negligible and will hamper the scalability of such broadcast designs. Further speed and density improvements through scaling can be secured by the fully pipelined design in which both data and control signals are restricted to local connections.     

Double-least-significant-bits 2's-complement number representation scheme with bitwise complementation and symmetric range

A scheme is proposed for representing 2's-complement binary numbers in which there are two least-significant bits (LSBs). Benefits of the extra LSB include making the number representation range symmetric (i.e. from -2^k-1 to 2^k-1 for k-bit integers), allowing sign change by simple bitwise logical inversion, facilitating multiprecision arithmetic and enabling the truncation of results in lieu of rounding. These advantages justify the added storage and interconnect costs stemming from the extra bit. Operation latencies show little or no change relative to conventional 2's-complement arithmetic, thus making double-LSB representation attractive.     

Voting algorithms

This paper presents efficient n-way plurality and threshold voting algorithms based on the type of voting (exact, inexact, or approval), rule for output selection (plurality or threshold) and properties of the input object space (size and structure). Exact voting is the most common voting method and is the easiest to implement. Inexact voting algorithms are more complicated due to intransitivity of approximate equality. In approval voting, each input to the voting process consists of a finite or infinite set of values that have been “approved” by the corresponding computation channel and the value, or set of values, with the highest approval voting must emerge as output. Multiple approved values can result from a nonunique answer to a given problem or from uncertainties in the solution process. For exact voting, the complexity of an n-way voting algorithm depends on the structure of the input object space. Threshold voting often requires less time and space, except when the threshold is very small. The author extends the techniques for designing efficient exact voting algorithms to inexact and approval voting schemes. Results show that optimal linear-time (in n) voting algorithms are available when the input object space is small. Next in the time-complexity hierarchy is the case of a totally-ordered object space that supports worst-case order-[n·log(n)]-time algorithms for both exact and inexact voting as well as for certain approval-voting schemes     

Induction of P-selectin by oxidized lipoproteins. Separate effects on synthesis and surface expression

Leukocyte binding to the endothelium is one of the earliest events in the occurrence of atherosclerosis. Leukocyte adhesion molecules involved in this process have not been definitely identified. We have found that treatment of human aortic endothelial cells (HAECs) with minimally modified low-density lipoprotein (MM-LDL) for 24 hours caused a 2- to 3-fold increase of P-selectin protein, with little change in P-selectin surface expression. A 15-minute histamine treatment of cells exposed to MM-LDL caused a 50% to 100% increase in P-selectin surface expression compared with cells not treated with the lipoprotein. This increase resulted in a 2-fold increase in binding of leukocytes to the endothelium. Immunostaining of permeabilized HAECs after MM-LDL treatment also revealed a highly reproducible increase in intracellular P-selectin associated with rod-shaped structures, typical of Weibel-Palade bodies. Oxidized phospholipids were shown to be mainly responsible for the action of MM-LDL. This increased P-selectin expression was associated with MM-LDL-induced cAMP elevation. Like histamine, highly oxidized low-density lipoprotein, especially the oxidized fatty acids, caused immediate redistribution of P-selectin to the cell surface followed by reinternalization. Immunohistochemical staining showed that endothelial cells on human fatty streak lesions expressed increased levels of P-selectin compared with nonlesion areas. These studies suggest that P-selectin may play an important role in early recruitment of mononuclear cells to the subendothelium in human atherosclerosis and that oxidized lipoproteins may contribute to the increased expression of this molecule by increasing intracellular stores and causing redistribution to the cell surface.     

Imparting insect repellency to nylon 6 fibers by means of a novel MCT reactive dye

Insect repellency of fiber is a property which makes the fiber to be of interest in the field of military and health. The insect‐repellent substrate could be prepared using either functional finishing or applying an insect‐repellent dye. In this article, insect‐repellent nylon 6 is obtained using a novel insect‐repellent reactive dye containing N,N‐diethyl‐m‐toluamide. To do this, N,N‐diethyl‐m‐toluamide (DEET) was first nitrated at the p‐position relative to amide functionality. The nitrated product was reduced in the presence of C₂H₅OH, SnCl₂, and HCl. The produced amine was then condensed with 2,4,6‐trichloro‐1,3,5‐triazine (cyanuric chloride) as a reactive group in below 5°C. The resultant adduct was finally reacted with an amino group present in 6‐amino‐1‐hydroxy naphthalene‐3‐sulfonic acid (J‐acid) to produce 7‐(4‐chloro‐6‐(4‐(diethylcarbamoyl)‐2‐methylphenylamino)‐1,3,5‐triazin‐2‐ylamino)‐4‐hydroxynaphthalene‐2‐sulfonic acid. To synthesis azo dye, sulfanilic acid was diazotized using HCl and NaNO₂ and then coupled to the above prepared component to produce insect‐repellent reactive dye. An analog dye was prepared via the same route without insect‐repellent group making stage. The chemical structures of the novel dyes were characterized using FTIR and ¹H‐NMR spectroscopy. The spectroscopic properties of the dyes were determined in terms of λ_max and ε_max in aqueous solution. The novel dyes were then reacted with nylon 6 and bonded to it covalently to provide permanent insect‐repellent substrate. The insect‐repellent efficacy of the reacted nylon 6 was studied using standard methods for Anophele mosquito repellent. The insect‐repellent dye reacted nylon 6 showed insect‐repellent activity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012