Comparative Performance Evaluation of Large FPGAs with CNFET- and CMOS-based Switches in Nanoscale

Nano-Micro Letters - Routing resources are the major bottlenecks in improving the performance and power consumption of the current FPGAs. Recently reported researches have shown that carbon...     

Modeling and analysis of flow energy harvesters made of PZT ceramics considering different patches,cross-sections,and tip bodies

A nonlinear developed model for various PZT wind energy harvesters with arbitrary dimensions and location of electroceramics has been prepared. This model can describe unimorph and bimorph harvesters with different cantilever cross-sections attached to a tip body with different shapes. The system model has been validated with results reported in the literature. A set of parametric studies has been conducted to examine the influences of the cantilever shape in addition to the shape of the tip body. Furthermore, the impacts of load resistance and wind speed on the output power have been analyzed. The effects of number, position, and dimensions of piezoceramics on the harvester performance have also been investigated. It is found that by increasing the total area of electroceramics (including the length, width, or the number of PZT patches), the peak of the wind critical speed and the middle resistance range where the instability speed is very sensitive to the electrical load shifts toward the lower resistances. Moreover, several instrumental points to design efficient and affordable vibrating wind harvesters at low and high flows have been obtained.     

Five New MVL Current Mode Differential Absolute Value Circuits Based on Carbon Nano-tube Field Effect Transistors (CNTFETs)

Nano-Micro Letters - Carbon Nano-Tube Field Effect Transistors (CNTFETs) are being widely studied as possible successors to silicon MOSFETs. Using current mode has many advantages such as...     

A symmetric quantum-dot cellular automata design for 5-input majority gate

By the inevitable scaling down of the feature size of the MOS transistors which are deeper in nanoranges, the CMOS technology has encountered many critical challenges and problems such as very high leakage currents, reduced gate control, high power density, increased circuit noise sensitivity and very high lithography costs. Quantum-dot cellular automata (QCA) owing to its high device density, extremely low power consumption and very high switching speed could be a feasible competitive alternative. In this paper, a novel 5-input majority gate, an important fundamental building block in QCA circuits, is designed in a symmetric form. In addition to the majority gate, a SR latch, a SR gate and an efficient one bit QCA full adder are implemented employing the new 5-input majority gate. In order to verify the functionality of the proposed designs, QCADesigner tool is used. The results demonstrate that the proposed SR latch and full adder perform equally well or in many cases better than previous circuits.     

Powder Metallurgical Fabrication and Characterization of Nanostructured Porous NiTi Shape-Memory Alloy

Production of NiTi alloy from elemental powders was conducted by mechanical alloying (MA) and sintering of the raw materials. Effects of milling time and milling speed (RPM) on crystallite size, lattice strain, and XRD peak intensities were investigated by X-ray analysis of the alloy. Powder compaction and sintering time and temperature effects on pore percentage of the as-mixed and the mechanically alloyed samples were empirically evaluated. The crystallite size of the mechanically alloyed Ni₅₀Ti₅₀ samples decreased with MA duration and with the milling speed. Depending on the crystal structure of the raw materials, the lattice strain increases with the milling duration. Metallographic studies proved the existence of martensitic B19' after sintering of both the as-mixed and the mechanically alloyed samples. Its amount was, however, greater for the former. Sintering lowered the porosity of the samples; no matter what powder (as-mixed or mechanically alloyed) was used. The porosity was greater, however, for the MA powders. This difference seemed to be due to the sharper liquid phase sintering effect of the as-mixed samples.     

A fast and reliable multi-sender algorithm for peer-to-peer networks

Due to special constraints in peer-to-peer (P2P) networks (such as bandwidth limitation) and because of their highly dynamic characteristics, a single node cannot provide a reliable multimedia stream to the receivers. Several multi-sender algorithms are proposed to reliably deliver a media stream to the receiver through the intrinsically unreliable P2P networks. Based on upload bandwidths and availability of peers as well as the bandwidths of the links connecting the senders and the receiver, PROMISE selects a set of active senders to maximize the expected bit-rate delivered to the receiver. By careful investigation of PROMISE, in this paper, we present why and how it deviates from finding the optimal solution. The proposed algorithm, we call IPROMISE, consistently provides a higher media quality to the receiver, with a computational complexity similar to PROMISE. We also introduce FastIPROMISE which provides the same quality as IPROMISE but requires much less computations. That is achieved by shrinking the search space.     

Efficient CNTFET-based Ternary Full Adder Cells for Nanoelectronics

Nano-Micro Letters - This paper presents two new efficient ternary Full Adder cells for nanoelectronics. These CNTFET-based ternary Full Adders are designed based on the unique characteristics of...     

Low temperature followed by matrix solid-phase dispersion-sonication procedure for the determination of multiclass pesticides in palm oil using LC-TOF-MS

A simple and effective multiresidue method based on precipitation at low temperature followed by matrix solid-phase dispersion-sonication was developed and validated to determine dimethoate, malathion, carbaryl, simazine, terbuthylazine, atrazine and diuron in palm oil using liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS). Liquid-liquid extraction (LLE) followed by low temperature method were optimized by studying the effect of type and volume of organic solvent (acetonitrile, acetonitrile:n-hexane (3:2 v/v) and acetone) and time of freezing to obtain high recovery yield and low co-extract fat residue in the final extract. The optimal conditions for matrix solid-phase dispersion (MSPD) were obtained using 5 g of palm oil, 2 g of primary secondary amine (PSA) as dispersing sorbent, 1 g of graphitized carbon black (GCB) as clean-up sorbent and 15 mL of acetonitrile as eluting solvent under conditions of 15 min ultrasonication at room temperature. Method validation was performed in order to study sensitivity, linearity, precision, and accuracy. Average recoveries at three concentration levels (25, 50 and 100 μg kg(-1)) were found in the range of 72.6-91.3% with relative standard deviations between 5.3% and 14.2%. Detection and quantification limits ranged from 1.5 to 5 μg kg(-1) and from 2.5 to 9 μg kg(-1), respectively.     

Peridynamic assessment of mechanical and thermal characteristics of a defected PMMA/HA composite beam

Polymer-based composites are designed to improve mechanical and thermal characteristics. This study utilized a peridynamic methodology to simulate polymethyl methacrylate/hydroxyapatite composite beams. The simulation involved the crack growth within the computational domain, and an analysis was conducted to evaluate the mechanical and thermal properties of the defected system. The outcomes derived from the peridynamic analysis revealed that an augmentation in the hydroxyapatite ratio within the samples resulted in a decrease in their mechanical and thermal efficiencies. To elucidate further, at an impact velocity of 2 mm/s, the flexural modulus increased to 3.69 GPa, the flexural strength decreased to 132.34 MPa, and the thermal conductivity converged to 0.148 W/m·K, when the hydroxyapatite ratio was at 15%. In the course of the conducted investigations, it became evident that the impact velocity significantly influences the evolutionary behavior of particles within the samples. In particular, with an increase in the impact velocity up to 5 mm/s, the thermal conductivity decreased to 0.139 W/m·K. The results of this study indicate that by modifying the hydroxyapatite ratio and impact velocity, it is possible to control the mechanical and thermal properties of the polymethyl methacrylate/hydroxyapatite composite beams. This optimization allows for their suitability in various engineering applications.     

Developing a Model for Decision-Makers in Dynamic Modeling of Urban Water System Management

Water managers may modify many components of urban water systems to minimize water shortage. Since each modification activity has its own positive and negative effects, it is necessary to define an appropriate procedure to predict the consequences of each action. As the parameters of urban water supply and demand system have internal relationships in the time domain, a dynamic model is needed to forecast the result of changes and select the best modification activity. Here the Vensim® is applied as a modeling tool to choose the most effective water management activities in Tehran province. It has been found that the annual increase rate of water tariff by 16.4% and assigning 4.5% of revenue on reducing non-revenue water may be the most effective demand management activity to reduce water shortage in Tehran province. It has also been revealed that, even by implementing the most effective demand management activities in Tehran, the amount of required water in the next 10 years is more than the sustainable capacity of its resources and activities like seawater desalination are inevitable to prevent unsustainable use of water sources.