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Minimizing power consumption is vitally important in embedded system design; power consumption determines battery lifespan. Ultra-low-power designs may even permit embedded systems to operate without batteries by scavenging energy from the environment. Moreover, managing power dissipation is now a key factor in integrated circuit packaging and cooling. As a result, embedded system price, size, weight, and reliability are all strongly dependent on power dissipation. Recent developments in nanoscale devices open new alternatives for low-power embedded system design. Among these, single-electron tunneling transistors (SETs) hold the promise of achieving the lowest power consumption. Unfortunately, most analysis of SETs has focused on single devices instead of architectures, making it difficult to determine whether they are appropriate for low-power embedded systems. Evaluating the use of SETs in large-scale digital systems requires novel architectural and circuit design. SET-based design imposes numerous challenges resulting from low driving strength, relatively large static power consumption, and the presence of reliability problems resulting from random background charge effects. We propose a fault-tolerant, hybrid SET/CMOS, reconfigurable architecture, named IceFlex, that can be tailored to specific requirements and allows tradeoffs among power consumption, performance requirements, operation temperature, fabrication cost, and reliability. Using IceFlex as a testbed, we characterize the benefits and limitations of SETs in embedded system designs. In particular, we focus on the use of SETs in room-temperature ultra-low-power embedded systems such as wireless sensor network nodes. We also consider high-performance applications such as multimedia consumer electronics. We see this work as a first step in determining the potential of ultra-low-power embedded system design using SETs. [ABSTRACT FROM AUTHOR]

Abstract: The layered double hydroxides (LDHs) containing nitrate as the interlayer anion has a high anion-exchange capacity in the presence of appropriate anions. In the light of this, ZnAl-NO3 LDHs have been employed to remove chloride ion from aqueous solution in a batch mode. The influences of conditions for chloride ion uptake, including dosage of LDHs, pH of aqueous solution, and temperature on anion-exchange have been investigated, respectively. The thermodynamic parameters including Gibbs free energy (ΔG 0), standard enthalpy change (ΔH 0), and standard entropy change (ΔS 0) for the process were calculated using the Langmuir constants. It was found from kinetics test that the pseudo-second order kinetics model could be used to well describe the uptake process. An E a value of 10.27kJ/mol provides evidence the anion-exchange process. The explanation of anion-exchange phenomenon has also been supported by X-ray diffraction and FT-IR spectra. [Copyright &y& Elsevier]