Punch-through impact ionization MOSFET (PIMOS): From device principle to applications

In the present work a punch-through impact ionization MOSFET (PIMOS) is presented, which exploits impact ionization in low-doped body-tied Ω- and tri-gate structures to obtain abrupt switching (3–10 mV/decade) combined with a hysteresis in the I_D(V_DS) and I_D(V_GS) characteristics. The PIMOS device shows an extraordinary temperature stability up to 125 °C. The influence of various parameters on device performance as abrupt switch or memory cell is investigated. Reduction of the electrical channel length, i.e. of gate length and/or substrate doping, reduces the breakdown voltage and hence the DRAM operating voltage, but also increase the I_off. Two architectures for a capacitor-less DRAM cell are demonstrated and evaluated. In addition, a PIMOS n-type hysteretic inverter is demonstrated, which may serve as a 1T SRAM cell.     

Reducing the Number of Comparators in Multibt $Delta Sigma $ Modulators

Multibit feedback, being one way of lowering DeltaSigma modulators power consumption, has a major obstacle: the number of components in the internal analog-to-digital converter (ADC) and digital-to-analog converter (DAC). Nevertheless, the number of comparators in the ADC can be significantly reduced depending on the order of noise-shaping and the oversampling ratio. In this paper, we propose an auto-ranging algorithm with a mechanism to keep the structure stable that emulates more quantization levels than that allowed by the number of comparators. As the recourse to segmented DACs allows lowering the complexity of the mismatch shaping encoder, the auto-ranging ADC brings the benefits of multibit feedback without the usual increase in size and power consumption. The internal number of bits in DeltaSigma modulators is no more restricted by the difficulty of building the flash ADC with a low voltage supply.     

Simultaneous Determination of Naproxen and Diflunisal using Synchronous Luminescence Spectrometry

Binary mixtures of naproxen and diflunisal can be resolved by using zero-crossing first derivative emission spectrofluorimetry, first derivative constant wavelength synchronous luminescence spectrometry and first derivative constant energy synchronous luminescence spectrometry. These methods do not require any previous separation steps. The lowest quantitation limits for both drugs were obtained with first derivative constant wavelength synchronous luminescence spectrometry (0.002 and 0.015 μg ml⁻¹ for naproxen and diflunisal, respectively). The measurements were performed in 40% methanolic aqueous medium at pH 8.0 provided by adding 0.02 M phosphate buffer solution. The proposed methods were successfully applied to the simultaneous determination of naproxen and diflunisal in pharmaceuticals and human serum samples with high precision and accuracy. Linearity, accuracy, precision, limits of detection, limits of quantitation, and other aspects of analytical validation are included in the text.     

Graphene to graphite; a layer by layer experimental measurements and density function theory calculations of electric conductivity

ABSTRACT

We measured the electric conductivity of large (25?×?50?mm) graphene films as a function of number of layers in the range of 1–20 layers. We also calculated the energy gap for such samples using density function theory. Our results showed a conductivity slightly above that of ITO for monolayer graphene and an exponential decrease as the number of graphene layers increased. Both experimental and simulation results showed a convergence of graphene into graphite at as little as 18–20 layers.     

Implementing IoT/WSN based smart Saskatchewan Healthcare System

Wireless Networks - The Internet of Things (IoT) technology has recently experienced popularity and growth in every facet of life, and it has been applied to every industry in recent years. The...     

One-pot synthesis,spectroscopic characterization and DFT study of novel 8-azacoumarin derivatives as eco-friendly insecticidal agents

A series of sixteen 8-azacoumarin derivatives bearing aryl moieties at C-5 and C-7 was designed and synthesized by a concise and facile procedure utilizing grinding and ultrasound approaches. The efficient multi-component protocols proceeded smoothly and in the absence of solvent to furnish the target products in moderate to good yields. All the synthesized molecules were characterized via ¹HNMR, ¹³CNMR, IR, mass spectra, and elemental analyses. The density functional theory (DFT) was then used to discover the structural and electronic characteristics of such compounds. Finally, an insecticidal study against Plutella xylostella and Helicoverpa armigera on the synthesized compounds is reported. The bioassay results indicated that some of the tested compounds showed potency ranging from good to moderate. In particular, analogs 6i and 6l, among the tested compounds, showed even more potency than commercial chlorpyrifos. On the other hand, the rest of the tested compounds showed moderate to weak activities.     

Arylhydrazonals as the aldehyde component in Baylis-Hillman reactions

Arylhydrazonals were added to acrylonitrile or methyl vinyl ketone in the presence of DABCO or benzotriazole to yield the intermediate Baylis-Hillman adduct that cyclized under the reaction conditions with water elimination to yield dihydropyridazines. A pyridazine reacted with DMAD to yield a pyridine via a [4+2] Diels-Alder addition followed by retro Diels-Alder elimination of methylene aniline. Two pyridazines were condensed with DMFDMA to yield the corresponding enaminones that reacted with NH₂NH₂ to afford the pyrazolylpyridazines.     

Gas‐phase thermolysis of benzotriazole derivatives. Part 4. Pyrolysis of 1‐acylbenzotriazole phenylhydrazones. Interesting direct routes towards N‐aminobenzimidazoles

Flash vacuum pyrolysis (FVP) of 1‐acylbenzotriazole phenylhydrazones gave benzonitriles, aniline and 2‐arylbenzimidazole derivatives. Static pyrolysis of the same substrates at 180 °C gave exclusively the corresponding N‐anilino‐2‐arylbenzimidazole derivatives. Pyrolysis of the isomeric 2‐acylbenzotriazole phenylhydrazones gave similar products.     

Glucose-based surfactants with hydrogenated, fluorinated, or hemifluorinated tails: synthesis and comparative physical-chemical characterization

(Hemi)fluorinated hydrophobic chains have been found to minimize the denaturating propensity of surfactants toward membrane proteins. The work reported herein deals with the synthesis of a new series of non-ionic glucose-based surfactants endowed with a hybrid hemifluorocarbon chain. The convergent synthesis is based on a one-pot reduction/alkylation of hemifluorinated thioacetate and glucosylated trishydroxymethyl acrylamidomethane using NaBH4 in methanol. This "mild" alkylation was studied in order to improve yields and to pass up the use of an excess of commercially unavailable hemifluorinated thiols. The physical-chemical properties in aqueous solution of this novel series were studied by surface tension measurement and dynamic light scattering (DLS), as well as their behavior upon reverse-phase chromatography, and were compared with those of their hydrogenated and perfluorinated analogues. The atypical effect of the additional ethyl tip to the fluorinated chain was demonstrated by higher critical micellar concentration values and abnormal hydrophobicities measured by reverse-phase chromatography. Moreover, according to Israelachvili's concept, DLS studies showed that surfactants bearing bulkier polar head self-assemble into small and well-defined aggregates, suggesting the formation of spherical micelles rather than the cylindrical ones usually observed with classical fluorinated surfactants.