A Novel Charge Recycling Design Scheme Based on Adiabatic Charge Pump

Power consumption has become a critical design criterion for integrated circuits given the growing importance of portable battery-operated devices. A typical CMOS gate driven by power supply (V_DD), draws energy equal to C_LV_DD ² during every cycle of operation. We propose a new approach to recycle the charge with an adiabatic charge pump that moves the slower adiabatic components away from the critical path of logic. The critical path of the system, and hence the delay, do not change. This is achieved by overlapping the adiabatic charge pump delays with the computing path logic delays. Many embedded high performance applications such as digital signal processing (DSP), which exhibit datapath parallelism, are ideal candidates for this scheme. The proposed method has been implemented in DSP computations. SPICE simulations-based results indicate that the proposed scheme reduces energy consumption in these DSP circuits by as much as 18% (on average 9.94%) with no perceptible loss in performance. The area penalty for these energy savings are in the 1%-2% range, The leakage energy reduction in 45-nm BPTM averages 46%.     

XRules: An effective algorithm for structural classification of XML data

XML documents have recently become ubiquitous because of their varied applicability in a number of applications. Classification is an important problem in the data mining domain, but current classification methods for XML documents use IR-based methods in which each document is treated as a bag of words. Such techniques ignore a significant amount of information hidden inside the documents. In this paper we discuss the problem of rule based classification of XML data by using frequent discriminatory substructures within XML documents. Such a technique is more capable of finding the classification characteristics of documents. In addition, the technique can also be extended to cost sensitive classification. We show the effectiveness of the method with respect to other classifiers. We note that the methodology discussed in this paper is applicable to any kind of semi-structured data. Editors: Hendrik Blockeel, David Jensen and Stefan Kramer An erratum to this article is available at .     

Changes in electronic and optical characteristics of halogen–alkali adsorbed WSe2 monolayer

Journal of Materials Science: Materials in Electronics - Adsorbing halogen and alkali metals atoms modify the optical and electrical characteristics of WSe2 monolayer (2D). The electrical and...     

Nanostructured La(Sr)CrO3 through gel combustion: sintering and electrical behavior

Nanostructured La(Sr)CrO3 (LSC) powders was prepared through glycine-nitrate gel combustion process. It was shown for the first time that the use of relatively inexpensive CrO3 as a starting material for chromium has a potential for the bulk preparation of sinter-active LSC powder. As-prepared powder when calcined at 700 degrees C resulted in LSC along with a small amount of SrCrO4 as a secondary phase. The powder was found to be composed of soft agglomerates with a particle size of approximately 70-270 nm. The average agglomerate size was found to be 0.95 microm. The cold pressing and sintering of the LSC powder at 1450 degrees C resulted in mono-phasic La0.8Sr0.2CrO3 with 94% of its theoretical density. This is the lowest sintering temperature ever reported for La0.8Sr0.2CrO3. The conductivity of the sintered La0.8Sr0.2CrO3 at 1000 degrees C was found to be approximately 18 S cm(-1).     

亚麻/粘胶混纺纱

亚麻是一种天然纤维 ,在中国种植了大约6 5万公顷 ,在印度、巴基斯坦、孟加拉等国也有大量栽培。基于亚麻的一些物理特性 ,例如强度和耐磨性 ,它早期的用途仅限于做包装及装饰织物。然而 ,最近关于亚麻纱线用途的研究表明 :不同细度及纤维混纺比的纱线可以用来生产新型的轻质服装、礼服、衬衫和床上用品。尽管由于亚麻纤维高的刚度会使这些织物手感粗糙 ,但是纤维的亲水特性开启了其在机织及针织服用纺织品领域新的发展。通过转杯纺、包缠纺和摩擦纺 ,可以将亚麻纤维纺成短纤纱。但是 ,在亚麻纱的机织和针织加工中要进一步解决其弹性低和短…     

Significance of Al on the morphological and optical properties of Ti1−xAlxN thin films

TiN and Ti_1−xAl_xN thin films with different aluminum concentrations (x = 0.35, 0.40, 0.55, 0.64 and 0.81) were synthesized by reactive magnetron co-sputtering technique. The structure, surface morphology and optical properties were examined using Grazing Incidence X-ray Diffraction (GIXRD), Atomic Force Microscopy (AFM), Raman spectroscopy and spectroscopic ellipsometry, respectively. The structure of the films were found to be of rocksalt type (NaCl) for x = 0.0–0.64 and X-ray amorphous for x = 0.81. AFM topographies show continuous mound like structure for the films of x between 0.0 and 0.64, whereas the film with x = 0.81 showed smooth surface with fine grains. Micro-Raman spectroscopic studies indicate structural phase separation of AlN from TiAlN matrix for x > 0.40. Ti_1−xAl_xN has the tendency for decomposition with the increase of Al concentration whereas c-TiN and hcp-AlN are stable mostly. The optical studies carried out by spectroscopic ellipsometry measurements showed a change from metallic to insulating behavior with the increase in x. These films are found to be an insulator beyond x = 0.81.     

Pomace waste management scenarios in Québec--impact on greenhouse gas emissions

Fruit processing industries generate tremendous amount of solid wastes which is almost 35-40% dry weight of the total produce used for the manufacturing of juices. These solid wastes, referred to as, “pomace” contain high moisture content (70-75%) and biodegradable organic load (high BOD and COD values) so that their management is an important issue. During the management of these pomace wastes by different strategies comprising incineration, landfill, composting, solid-state fermentation to produce high-value enzymes and animal feed, there is production of greenhouse gases (GHG) which must be taken into account. In this perspective, this study is unique that discusses the GHG emission analysis of agro-industrial waste management strategies, especially apple pomace waste management and repercussions of value-addition of these wastes in terms of their sustainability using life cycle assessment (LCA) model. The results of the analysis indicated that, among all the apple pomace management sub-models for a functional unit, solid-state fermentation to produce enzymes was the most effective method for reducing GHG emissions (906.81 tons CO₂ eq. per year), while apple pomace landfill resulted in higher GHG emissions (1841.00 tons CO₂ eq. per year). The assessment and inventory of GHG emissions during solid-state fermentation gave positive indications of environmental sustainability for the use of this strategy to manage apple pomace and other agricultural wastes, particularly in Quebec and also extended to other countries. The analysis and use of parameters in this study were drawn from various analytical approaches and data sources. There was absence of some data in the literature which led to consideration of some assumptions in order to calculate GHG emissions. Hence, supplementary experimental studies will be very important to calculate the GHG emissions coefficients during agro-industrial waste management.     

A Wideband RF Frontend Architecture for Software Defined Radio

This paper presents an RF front-end architecture for wideband software defined radio to function in 400 MHz to 3.5 GHz frequency range. The frequency range covers almost all the existing standards (like GSM, UMYS, CDMA, WiFi etc.) as well as future standards (like WiMax which is still to be deployed). Although the 400 MHz–3.5 GHz band is taken, the architecture allows designers to design the front-end for any range of frequencies. In wideband front-ends, devices with high linearity are used to lower the level of intermodulation products. There are different front-end architectures available for catering to wideband operation. However, some of these, particularly the wideband ones suffer with intermodulation problem. This paper presents a partitioning mechanism that uses multiple medium bands to limit the intermodulation problem. The proposed frequency-partitioning scheme makes it possible to suppress intermodulation products further for front-end using devices of given linearity. Thus this helps in achieving better performance along with relaxing the linearity requirement of devices.     

Double-Doping Approach to Enhancing the Thermoelectric Figure-of-Merit of n-Type Mg2Si Synthesized by Use of Spark Plasma Sintering

We report significant enhancement of the thermoelectric figure-of-merit of Mg₂Si by double-doping with a combination of Bi, Pb, and Sb as doping elements. Addition of any two of these three elements to Mg₂Si increases the electrical conductivity by more than three orders of magnitude at 323 K, irrespective of the doping elements used. However, a corresponding decrease in the Seebeck coefficient is observed in comparison with undoped Mg₂Si. Irrespective of the combination of the three elements used for double doping, a figure-of-merit of approximately 0.7 at 873 K is obtained for Mg₂Si; this is primarily because of enhancement of the electrical conductivity.     

A Survey on Various Coherent and Non-coherent IR-UWB Receivers

The recent developments in radio technologies, paves its way to impulse radio (IR) ultra-wideband (UWB) communication, which is used for low power, short range and high bandwidth communication, thereby exploiting a large portion of radio spectrum. In this paper, a brief review of the work done by various researchers on coherent and non-coherent IR-UWB receivers has been analysed, based on their bit error rate (BER) performances, as well as pros and cons of using these receivers. An in depth study on the receivers concludes that, non-coherent IR-UWB receiver is preferred over its counterpart coherent IR-UWB receiver even though it comes at the expense of poor BER performance. The simulation results prove that, though the performances are same, the low complexity of energy detector (ED) receivers gives an edge over the autocorrelation receivers. Further, ED receiver suffers from noise, which paves way to using weighted ED (WED) receiver. The superiority of WED receivers over all the other non-coherent UWB receivers is further confirmed by the simulation performed in AWGN and IEEE 802.15.4a UWB channels. It can also be concluded from the review that, some special receivers such as generalized likelihood ratio test, multi-symbol differential detector and decision feedback differential transmitted reference, when clubbed with UWB systems, lead to further improvement in BER performance.