High performance VLSI architecture design for H.264 CAVLC decoder

H.264 video standard achieves high quality video along with high data compression when compared to other existing video standards. H.264 uses context-based adaptive variable length coding (CAVLC) to code residual data in Baseline profile. In this paper we describe a novel architecture for CAVLC decoder including coeff-token decoder, level decoder total-zeros decoder and run-before decoder UMC library in 0.13 mu CMOS technology is used to synthesize the proposed design. The proposed design reduces chip area and improves critical path performance of CAVLC decoder in comparison with [1]. Macroblock level (including luma and chroma) pipeline processing for CAVLC is implemented with an average of 141 cycles (including pipeline buffering) per macroblock at 250MHz clock frequency. To compare our results with [1] clock frequency is constrained to 125MHz. The area required for the proposed architecture is 17586 gates, which is 22.1% improvement in comparison to [1]. We obtain a throughput of 1.73 * 10(6) macroblocks/second, which is 28% higher than that reported in [1]. The proposed design meets the processing requirement of 1080HD [5] video at 30frames/seconds.

Excellent performance of Pt-free cathode in alkaline direct methanol fuel cell at room temperature

We report the room temperature cell performance of alkaline direct methanol fuel cells (ADMFCs) with nitrogen-doped carbon nanotubes (NCNTs) as cathode materials. NCNTs show excellent oxygen reduction reaction activity and methanol tolerance in alkaline medium. The open-circuit-voltage (OCV) as well as the power density of ADMFCs first increases and then saturates with NCNT loading. Similarly, the OCV initially increases and reaches saturation with the increase in the concentration of methanol feed stock. Overall, NCNTs exhibit excellent catalytic activity and stability with respect to Pt based cathodes.

Superior Performance of a MoS2-RGO Composite and a Borocarbonitride in the Electrochemical Detection of Dopamine, Uric Acid and Adenine

A MoS2-RGO composite and borocarbonitride (BC5N) have been used as electrodes to selectively detect dopamine and uric acid in the presence of ascorbic acid. Both the electrodes show excellent eletrocatalytic activity towards the detection of dopamine, the detection limits being 0.55 mu M and 2.1 mu M in the case of MoS2-RGO and BCN respectively. MoS2-RGO shows a linear range of current over the 1-110 mu M concentrations of dopamine, while BCN shows over the 2.3-20 mu M range. BCN also exhibits satisfactory performance in the oxidation of uric acid with a detection limit of 3.8 mu M and the linear range from 4 to 40 mu M. The MoS2-RGO has also been used to detect adenine as well.

No More HF: Teflon-Assisted Ultrafast Removal of Silica to Generate High-Surface-Area Mesostructured Carbon for Enhanced CO2 Capture and Supercapacitor Performance

An innovative technique to obtain high-surface-area mesostructured carbon (2545m(2)g(-1)) with significant microporosity uses Teflon as the silica template removal agent. This method not only shortens synthesis time by combining silica removal and carbonization in a single step, but also assists in ultrafast removal of the template (in 10min) with complete elimination of toxic HF usage. The obtained carbon material (JNC-1) displays excellent CO2 capture ability (ca. 26.2wt% at 0 degrees C under 0.88bar CO2 pressure), which is twice that of CMK-3 obtained by the HF etching method (13.0wt%). JNC-1 demonstrated higher H-2 adsorption capacity (2.8wt%) compared to CMK-3 (1.2wt%) at -196 degrees C under 1.0bar H-2 pressure. The bimodal pore architecture of JNC-1 led to superior supercapacitor performance, with a specific capacitance of 292Fg(-1) and 182Fg(-1) at a drain rate of 1Ag(-1) and 50Ag(-1), respectively, in 1m H2SO4 compared to CMK-3 and activated carbon.

No More HF: Teflon-Assisted Ultrafast Removal of Silica to Generate High-Surface-Area Mesostructured Carbon for Enhanced CO2 Capture and Supercapacitor Performance

An innovative technique to obtain high-surface-area mesostructured carbon (2545m(2)g(-1)) with significant microporosity uses Teflon as the silica template removal agent. This method not only shortens synthesis time by combining silica removal and carbonization in a single step, but also assists in ultrafast removal of the template (in 10min) with complete elimination of toxic HF usage. The obtained carbon material (JNC-1) displays excellent CO2 capture ability (ca. 26.2wt% at 0 degrees C under 0.88bar CO2 pressure), which is twice that of CMK-3 obtained by the HF etching method (13.0wt%). JNC-1 demonstrated higher H-2 adsorption capacity (2.8wt%) compared to CMK-3 (1.2wt%) at -196 degrees C under 1.0bar H-2 pressure. The bimodal pore architecture of JNC-1 led to superior supercapacitor performance, with a specific capacitance of 292Fg(-1) and 182Fg(-1) at a drain rate of 1Ag(-1) and 50Ag(-1), respectively, in 1m H2SO4 compared to CMK-3 and activated carbon.

The top 100 questions of importance to the future of global agriculture

Despite a significant growth in food production over the past half-century, one of the most important challenges facing society today is how to feed an expected population of some nine billion by the middle of the 20th century. To meet the expected demand for food without significant increases in prices, it has been estimated that we need to produce 70-100 per cent more food, in light of the growing impacts of climate change, concerns over energy security, regional dietary shifts and the Millennium Development target of halving world poverty and hunger by 2015. The goal for the agricultural sector is no longer simply to maximize productivity, but to optimize across a far more complex landscape of production, rural development, environmental, social justice and food consumption outcomes. However, there remain significant challenges to developing national and international policies that support the wide emergence of more sustainable forms of land use and efficient agricultural production. The lack of information flow between scientists, practitioners and policy makers is known to exacerbate the difficulties, despite increased emphasis upon evidence-based policy. In this paper, we seek to improve dialogue and understanding between agricultural research and policy by identifying the 100 most important questions for global agriculture. These have been compiled using a horizon-scanning approach with leading experts and representatives of major agricultural organizations worldwide. The aim is to use sound scientific evidence to inform decision making and guide policy makers in the future direction of agricultural research priorities and policy support. If addressed, we anticipate that these questions will have a significant impact on global agricultural practices worldwide, while improving the synergy between agricultural policy, practice and research. This research forms part of the UK Government's Foresight Global Food and Farming Futures project.

Transverse plane wave analysis of short elliptical chamber mufflers: An analytical approach

Short elliptical chamber mufflers are used often in the modern day automotive exhaust systems. The acoustic analysis of such short chamber mufflers is facilitated by considering a transverse plane wave propagation model along the major axis up to the low frequency limit. The one dimensional differential equation governing the transverse plane wave propagation in such short chambers is solved using the segmentation approaches which are inherently numerical schemes, wherein the transfer matrix relating the upstream state variables to the downstream variables is obtained. Analytical solution of the transverse plane wave model used to analyze such short chambers has not been reported in the literature so far. This present work is thus an attempt to fill up this lacuna, whereby Frobenius solution of the differential equation governing the transverse plane wave propagation is obtained. By taking a sufficient number of terms of the infinite series, an approximate analytical solution so obtained shows good convergence up to about 1300 Hz and also covers most of the range of muffler dimensions used in practice. The transmission loss (TL) performance of the muffler configurations computed by this analytical approach agrees excellently with that computed by the Matrizant approach used earlier by the authors, thereby offering a faster and more elegant alternate method to analyze short elliptical muffler configurations. (C) 2010 Elsevier Ltd. All rights reserved.

Tracking and Erosion of Silicone Rubber Nanocomposites under DC Voltages of both Polarities

In order to improve the tracking and erosion performance of outdoor polymeric silicone rubber (SR) insulators used in HV power transmission lines, micron sized inorganic fillers are usually added to the base SR matrix. In addition, insulators used in high voltage dc transmission lines are designed to have increased creepage distance to mitigate the tracking and erosion problems. ASTM D2303 standard gives a procedure for finding the tracking and erosion resistance of outdoor polymeric insulator weathershed material samples under laboratory conditions for ac voltages. In this paper, inclined plane (IP) tracking and erosion tests similar to ASTM D2303 were conducted under both positive and negative dc voltages for silicone rubber samples filled with micron and nano sized particles to understand the phenomena occurring during such tests. Micron sized Alumina Trihydrate (ATH) and nano sized alumina fillers were added to silicone rubber matrix to improve the resistance to tracking and erosion. The leakage current during the tests and the eroded mass at the end of the tests were monitored. Scanning Electron Microscopy (SEM) and Energy dispersive Xray (EDX) studies were conducted to understand the filler dispersion and the changes in surface morphology in both nanocomposite and microcomposite samples. The results suggest that nanocomposites performed better than microcomposites even for a small filler loading (4%) for both positive and negative dc stresses. It was also seen that the tracking and erosion performance of silicone rubber is better under negative dc as compared to positive dc voltage. EDX studies showed migration of different ions onto the surface of the sample during the IP test under positive dc which has led to an inferior performance as compared to the performance under negative dc.