Study of a simulated stream machine for dataflow computation

In this paper, a stream-based dataflow architecture is proposed, and its simulation model, which has helped to evaluate the effectiveness of the proposed architectural concept, is discussed. The machine integrates the conventional Von Neumann type of control flow subsystem with a dataflow processing element of token storage type. The control flow unit tackles the dynamic nature of the stream structure including input/output whereas the dataflow unit does the computation part in an applicative style. A pipelined version of the stream machine is also discussed. The effectiveness of the machine is studied by running a few example programs in the simulated machine. The machine is expected to be useful in real time signal processing applications.     

Enhancement of Corrosion Resistance of Zinc Coatings Using Green Additives

In the present work, morphology, microstructure, and electrochemical behavior of Zn coatings containing non-toxic additives have been investigated. Zn coatings were electrodeposited over mild steel substrates using Zn sulphate baths containing four different organic additives: sodium gluconate, dextrose, dextrin, and saccharin. All these additives are “green” and can be derived from food contents. Morphological and structural characterization using electron microscopy, x-ray diffraction, and texture co-efficient analysis revealed an appreciable alteration in the morphology and texture of the deposit depending on the type of additive used in the Zn plating bath. All the Zn coatings, however, were nano-crystalline irrespective of the type of additive used. Polarization and electrochemical impedance spectroscopic analysis, used to investigate the effect of the change in microstructure and morphology on corrosion resistance behavior, illustrated an improved corrosion resistance for Zn deposits obtained from plating bath containing additives as compared to the pure Zn coatings.     

Physicochemical Characterization of Interaction of Ibuprofen by Solid-State Milling with Aluminum Hydroxide

This present study is a preliminary exploration of the affinity between a carboxylic model drug ibuprofen and aluminum hydroxide. Ibuprofen was comilled with aluminum hydroxide in different weight ratios in the solid state and was characterized by scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and in vitro dissolution studies. XRD and SEM studies indicated complete interaction of ibuprofen with aluminum hydroxide and complete amorphization of aluminum hydroxide–ibuprofen complexed salt as well, on comilling with aluminum hydroxide at 1:2 ratio. FTIR data showed the disappearance of acid carbonyl peak with the appearance and the corresponding increase in absorbance of new signal at 1,682 cm^?1 in the 1:1 and 1:2 ibuprofen–aluminum hydroxide-comilled powder. The accompanied increase in the absorbance of carboxylate peak in the ibuprofen–aluminum hydroxide physical mixture, and 1:0.1, 1:0.5, 1:1, and 1:2 (IBA_pm, and IB₁A_0.1, IB₁A_0.5, IB₁A₁, and IB₁A₂, respectively) comilled powder indicated an acid–base reaction between ibuprofen and aluminum hydroxide. On storage at 40°C and 75% relative humidity (RH) for 10 weeks, XRD study showed the absence of reversion to the crystalline state and FTIR data revealed continued increase of new signal at 1,682 cm^?1 relative to carboxylic acid peak and no reappearance of carboxylic acid peak. In vitro dissolution studies revealed that the percent release of ibuprofen from the aluminum hydroxide-comilled powder is in the following order: IB₁A₂ < IB₁A₁ < ibuprofen crystal < ibuprofen milled alone < IB₁A_0.1 < IB₁A_0.5. Aluminum metal cation might have interacted to form a complex through the carboxyl and carbonyl groups of ibuprofen. Improved dissolution of drug associated with IB₁A_0.1 and IB₁A_0.5 is because of the absence of a new signal at 1,682 cm^?1 and improved amorphization of the drug to some extent. Dissolution of drug affected in IB₁A₂ and IB₁A₁ may be because of the insoluble stable complex formation.     

Mechanistic origins of multi-scale reinforcements in segmented polyurethane-clay nanocomposites

The objective of the present work is to get insights into the mechanistic origin of the reinforcement effects of nanoclay on a segmented polybutadiene polyurethane-urea system. To this end, a convergent analysis of the hard domain morphology and conformational state of soft segment in the nanocomposites was carried out by using a combination of complementary characterization techniques, namely, Fourier transform infrared spectroscopy, small angle neutron scattering, transmission electron microscopy, modulated differential scanning calorimetry and dynamic mechanical analysis. Analysis of small angle neutron scattering data by a combination of Percus–Yevick hard sphere and Zernike-Ornstein model coupled with direct visualization of the dispersed hard domain morphology from transmission electron microscopy provided insight on clay induced changes in the hard domain morphology. A monotonic decrease in the domain size as well as the average interdomain distance was observed with increasing nanoclay content in the polymer matrix. Analysis of the carbonyl stretching region from FTIR showed increased degree of hydrogen bonding for the urethane carbonyl groups of the nanocomposites compared to the neat matrix. A combination of calorimetric and dynamic mechanical analysis revealed the existence of a constrained amorphous region; quantified to be ≈ 16% at the highest clay content experimented. The manifestation of these morphological and conformational changes on the nano-, micro- and macro scale reinforcements in the nanocomposites was investigated by mechanical properties at these length scales using nanoindentation, DMA and tensile testing, respectively.     

Development of Minimal Diguanosinyl Motif toward RNA G-Quadruplex-Like Structures in Solution

Among the non-canonical structures of B-DNA, the G-quadruplex is of particular interest because of its well-defined conformation, high stability, and versatility. Herein we report our studies on the development of an amide-linked minimal diguanosinyl motif that forms a G-quadruplex-like structure in solution in the presence of potassium cations; various linear guanosine amino acid dimers were synthesized with linkers of different chain lengths to investigate the optimum flexibility required to form such structures.     

Energy and Network Balanced Distributed Clustering in Wireless Sensor Network

Wireless Personal Communications - Balancing energy consumption of sensor nodes to extend the network lifetime is a major concern for the energy constrained wireless sensor network. Improper load...     

Development of a framework for sustainable improvement in performance of coal mining operations

Clean Technologies and Environmental Policy - India is a developing country, where boosting of modern energy supply is the primary requirement for economic growth. About two-thirds of this energy...     

Developmental differences in implicit learning of spatial context.

The authors examined whether a form of implicit memory that has been unambiguously dissociated from conscious awareness--learning of spatial context on the contextual cuing task introduced by M. M. Chun and Y. Jiang (1998)--is mature in childhood as predicted by an evolutionary view of cognition. School-aged children did not show reliable learning relative to adults who performed the same version of the task or another version that slowed responses to match those of children. Thus, unreliable learning in childhood was mediated by immature implicit representations of spatial context rather than by slower baseline response speed. The present finding is inconsistent with the prediction of the evolutionary view of cognition but consistent with incomplete maturation of medial temporal lobes known to mediate contextual learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)