Radix-8 Booth Encoded Modulo Multiplier

Abstract To design an efficient integrated circuit in terms of area, power and speed, has become a challenging task in modern VLSI design field. The encryption and decryption of PKC algorithms are performed by repeated modulo multiplications these multiplications differ from those encountered in signal processing and general computing applications. The Residue Number System (RNS) has emerged as a promising alternative number representation for the design of faster and low power multipliers owing to its merit to distribute a long integer multiplication into several shorter and independent modulo multiplications. The multipliers are the essential elements of the digital signal processing such as filtering, convolution, transformations and Inner products. RNS has also been successfully employed to design fault tolerant digital circuits. The modulo multiplier is usually the noncritical data path among all modulo multipliers in such high-DR RNS multiplier. This timing slack can be exploited to reduce the system area and power consumption without compromising the system performance. With this precept, a family of radix-8 Booth encoded modulo multipliers, with delay adaptable to the RNS multiplier delay, is proposed. In this paper, the radix-8 Booth encoded modulo multipliers whose delay can be tuned to match the RNS delay. In the proposed multiplier, the hard multiple is implemented using small word-length ripple carry adders (RCAs) operating in parallel. The carry-out bits from the adders are not propagated but treated as partial product bits to be accumulated in the CSA tree. The delay of the modulo multiplier can be directly controlled by the word-length of the RCAs to equal the delay of the critical modulo multiplier of the RNS. By combining radix-8 Booth encoded modulo multiplier, CSA and prefix architecture of multiplier, for high speed and low-power is achieved

The chromatin architectural proteins HMGD1 and H1 bind reciprocally and have opposite effects on chromatin structure and gene regulation

Background: Chromatin architectural proteins interact with nucleosomes to modulate chromatin accessibility and higher-order chromatin structure. While these proteins are almost certainly important for gene regulation they have been studied far less than the core histone proteins. Results: Here we describe the genomic distributions and functional roles of two chromatin architectural proteins: histone H1 and the high mobility group protein HMGD1 in Drosophila S2 cells. Using ChIP-seq, biochemical and gene specific approaches, we find that HMGD1 binds to highly accessible regulatory chromatin and active promoters. In contrast, H1 is primarily associated with heterochromatic regions marked with repressive histone marks. We find that the ratio of HMGD1 to H1 binding is a better predictor of gene activity than either protein by itself, which suggests that reciprocal binding between these proteins is important for gene regulation. Using knockdown experiments, we show that HMGD1 and H1 affect the occupancy of the other protein, change nucleosome repeat length and modulate gene expression. Conclusion: Collectively, our data suggest that dynamic and mutually exclusive binding of H1 and HMGD1 to nucleosomes and their linker sequences may control the fluid chromatin structure that is required for transcriptional regulation. This study provides a framework to further study the interplay between chromatin architectural proteins and epigenetics in gene regulation

Kinetic modeling studies of heterogeneously catalyzed biodiesel synthesis reactions

The heterogeneously catalyzed transesterification reaction for the production of biodiesel from triglycerides was investigated for reaction mechanism and kinetic constants. Three elementary reaction mechanisms Eley-Rideal (ER), Langmuir-Hinshelwood-Hougen-Watson (LHHW), and Hattori with assumptions, such as quasi-steady-state conditions for the surface species and methanol adsorption, and surface reactions as the rate-determining steps were applied to predict the catalyst surface coverage and the bulk concentration using a multiscale simulation framework. The rate expression based on methanol adsorption as the rate limiting in LHHW elementary mechanism has been found to be statistically the most reliable representation of the experimental data using hydrotalcite catalyst with different formulations

Two-scale Moving Boundary Dynamics of Cancer Invasion:Heterotypic Cell Populations Evolution in Heterogeneous ECM

This book contains a collection of original research articles and review articles that describe novel mathematical modeling techniques and the application of those techniques to models of cell motility in a variety of contexts. The aim is to highlight some of the recent mathematical work geared at understanding the coordination of intracellular processes involved in the movement of cells. This collection will benefit researchers interested in cell motility as well graduate students taking a topics course in this area.

Photocatalytic behavior of Ba(Sb/Ta)2O6 perovskite for reduction of organic pollutants: Experimental and DFT correlation

We have synthesized closely packed hexagonal 2D plates and clustered nanoparticle morphologies of Ba(Sb/Ta)2O6 (BSTO) perovskite via the polymerizable complex method for photocatalytic dye degradation activities. The BSTO crystallized in a hexagonal structure. The presence of Ba2+, Sb5+, Ta5+, and O2− chemical states identified from XPS confirmed the formation of mixed Ba(Sb/Ta)2O6 phase accompanied with a minor amount of TaOx. Furthermore, BSTO showed excellent photocatalytic activity for the degradation of various organic dyes. The kinetic studies revealed 65.9%, 77.3%, 89.8%, and 84.2%, of Crystal Violet (CV), Methylene Blue (MB), Rhodamine blue (RhB), and Methylene Orange (MO), respectively, after irradiation of 180 min without using a cocatalyst. The formation of and OH−surface radicals, which are believed to facilitate the degradation of the dyes, are unveiled through first-principles Density Functional Theory (DFT) calculations and scavenging studies. Our results suggest that BSTO holds promise as an excellent photocatalyst with better degradation efficiency for various organic dyes

On the influence of Si:Al ratio and hierarchical porosity of FAU zeolites in solid acid catalysed esterification pretreatment of bio-oil

A family of faujasite (FAU) zeolites with different Si:Al ratio, and/or hierarchical porosity introduced via post-synthetic alkaline desilication treatment, have been evaluated as solid acid catalysts for esterification pretreatments of pyrolysis bio-oil components. Acetic acid esterification with aliphatic and aromatic alcohols including methanol, anisyl alcohol, benzyl alcohol, p-cresol and n-butanol was first selected as a model reaction to identify the optimum zeolite properties. Materials were fully characterised using N2 porosimetry, ICP, XRD, XPS, FT-IR, pyridine adsorption, NH3 TPD, In-situ ATR and inverse gas chromatography (IGC). IGC demonstrates that the surface polarity and hence hydrophobicity of FAU decreases with increased Si:Al ratio. Despite possessing a higher acid site loading and acetic acid adsorption capacity, high Al-content FAU possess weaker acidity than more siliceous catalysts. Esterification activity increases with acid strength and decreasing surface polarity following the order FAU30>FAU6>FAU2.6. The introduction of mesoporosity through synthesis of a hierarchical HFAU30 material further enhances esterification activity through improved acid site accessibility and hydrophobicity. Methanol was the most reactive alcohol for esterification, and evaluated with HFAU30 for the pretreatment of a real pyrolysis bio-oil, reducing the acid content by 76% under mild conditions

Catalysing sustainable fuel and chemical synthesis

Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this century’s grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands