Stability improvement of an efficient graphene nanoribbon field-effect transistor-based sram design

The development of the nanoelectronics semiconductor devices leads to the shrinking of transistors channel into nanometer dimension. However, there are obstacles that appear with downscaling of the transistors primarily various short-channel effects. Graphene nanoribbon field-effect transistor (GNRFET) is an emerging technology that can potentially solve the issues of the conventional planar MOSFET imposed by quantum mechanical (QM) effects. GNRFET can also be used as static random-access memory (SRAM) circuit design due to its remarkable electronic properties. For high-speed operation, SRAM cells are more reliable and faster to be effectively utilized as memory cache. The transistor sizing constraint affects conventional 6T SRAM in a trade-off in access and write stability. This paper investigates on the stability performance in retention, access, and write mode of 15 nm GNRFET-based 6T and 8T SRAM cells with that of 16 nm FinFET and 16 nm MOSFET. The design and simulation of the SRAM model are simulated in synopsys HSPICE. GNRFET, FinFET, and MOSFET 8T SRAM cells give better performance in static noise margin (SNM) and power consumption than 6T SRAM cells. The simulation results reveal that the GNRFET, FinFET, and MOSFET-based 8T SRAM cells improved access static noise margin considerably by 58.1%, 28%, and 20.5%, respectively, as well as average power consumption significantly by 97.27%, 99.05%, and 83.3%, respectively, to the GNRFET, FinFET, and MOSFET-based 6T SRAM design. © 2020 Mathan Natarajamoorthy et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

On Multiphase-Linear Ranking Functions

Multiphase ranking functions ($\mathit{M{\Phi}RFs}$) were proposed as a means to prove the termination of a loop in which the computation progresses through a number of "phases", and the progress of each phase is described by a different linear ranking function. Our work provides new insights regarding such functions for loops described by a conjunction of linear constraints (single-path loops). We provide a complete polynomial-time solution to the problem of existence and of synthesis of $\mathit{M{\Phi}RF}$ of bounded depth (number of phases), when variables range over rational or real numbers; a complete solution for the (harder) case that variables are integer, with a matching lower-bound proof, showing that the problem is coNP-complete; and a new theorem which bounds the number of iterations for loops with $\mathit{M{\Phi}RFs}$. Surprisingly, the bound is linear, even when the variables involved change in non-linear way. We also consider a type of lexicographic ranking functions, $\mathit{LLRFs}$, more expressive than types of lexicographic functions for which complete solutions have been given so far. We prove that for the above type of loops, lexicographic functions can be reduced to $\mathit{M{\Phi}RFs}$, and thus the questions of complexity of detection and synthesis, and of resulting iteration bounds, are also answered for this class.Comment: typos correcte

Proving Termination Starting from the End

We present a novel technique for proving program termination which introduces a new dimension of modularity. Existing techniques use the program to incrementally construct a termination proof. While the proof keeps changing, the program remains the same. Our technique goes a step further. We show how to use the current partial proof to partition the transition relation into those behaviors known to be terminating from the current proof, and those whose status (terminating or not) is not known yet. This partition enables a new and unexplored dimension of incremental reasoning on the program side. In addition, we show that our approach naturally applies to conditional termination which searches for a precondition ensuring termination. We further report on a prototype implementation that advances the state-of-the-art on the grounds of termination and conditional termination.Comment: 16 page

Performance analysis of an efficient montgomery multiplier using 7nm FinFET and junctionless FinFET

The digital multipliers are the assertive sources of power exhaustion in the modern digital systems. To perform most efficient arithmetic based calculations, Montgomery multiplication can be one of the best alternatives for other conventional methods in digital architecture as high-speed multipliers are desired for its remarkable performance. The main drawback of the digital multipliers is that power exhaustion is very high when compared to the other elements of the digital circuit. Shift register is the one of the most important component in a digital multiplier which consumes comparatively higher power than the other components. Shift registers contains a series of D-flip flops to store the digital data. In order to obtain a notable improvement in terms of power consumption at the chip level, the flip-flop can be modified to achieve the reduction of average power in the multiplier. The Fin-Field Effect Transistor (FinFET) is a promising candidate to overcome fundamental limitations of its Silicon based alternative MOSFET. However, there seems to be an increase in leakage power and delay. The Junctionless FinFET with uniform doping in the channel proves to offer a better performance in terms of overall speed, power consumption and power delay product. The architecture has been designed in 7nm FinFET and JL-FinFET in Synopsys HSpice and Silvaco TCAD. The results of the Montgomery Multiplier affirms that the overall energy is improved by 55% and speed of the device by 35% as compared to the existing Montgomery Multiplier

Non-polynomial Worst-Case Analysis of Recursive Programs

We study the problem of developing efficient approaches for proving worst-case bounds of non-deterministic recursive programs. Ranking functions are sound and complete for proving termination and worst-case bounds of nonrecursive programs. First, we apply ranking functions to recursion, resulting in measure functions. We show that measure functions provide a sound and complete approach to prove worst-case bounds of non-deterministic recursive programs. Our second contribution is the synthesis of measure functions in nonpolynomial forms. We show that non-polynomial measure functions with logarithm and exponentiation can be synthesized through abstraction of logarithmic or exponentiation terms, Farkas' Lemma, and Handelman's Theorem using linear programming. While previous methods obtain worst-case polynomial bounds, our approach can synthesize bounds of the form $\mathcal{O}(n\log n)$ as well as $\mathcal{O}(n^r)$ where $r$ is not an integer. We present experimental results to demonstrate that our approach can obtain efficiently worst-case bounds of classical recursive algorithms such as (i) Merge-Sort, the divide-and-conquer algorithm for the Closest-Pair problem, where we obtain $\mathcal{O}(n \log n)$ worst-case bound, and (ii) Karatsuba's algorithm for polynomial multiplication and Strassen's algorithm for matrix multiplication, where we obtain $\mathcal{O}(n^r)$ bound such that $r$ is not an integer and close to the best-known bounds for the respective algorithms.Comment: 54 Pages, Full Version to CAV 201

Efficiency Droop Of InGaN/GaN Led With Different Indium Composition

III-nitride light emitting diodes (LEDs) have attracted considerable attraction due to their various applications in displays and illumination lighting. Nevertheless, the majority of InGaN/GaN LEDs suffer from the efficiency droop. This droop would limit the potential of the LEDs in high current applications. As widely reported, high indium content in InGaN/GaN multiquantum well active region of the LED promotes indium fluctuation that degrades the efficiency of the LED. In this work, we will present results of the efficiency droop for InGaN/GaN LED with indium content of 18% and 8%, respectively. The efficiency droop of the LED with 18% of indium shows higher efficiency droop than the LED with 8% of indium content

Insights on the climatic evolution at the pre-Jaramillo to Jaramillo transition in Europe using mineralogical analysis of the Quibas palaeontological site (Early Pleistocene, southern Iberian Peninsula)

© The Authors, 2023. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits use, copy, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source. This document is the Published version of a Published Work that appeared in final form in Spanish Journal of Palaeontology. To access the final edited and published work see https://doi.org/10.7203/sjp.27562The palaeontological site of Quibas is a karst outcrop with an age between 1.1 and 0.9 Ma (late Early Pleistocene). It represents the unique continuous sequence of terrestrial vertebrates of pre-Jaramillo to Jaramillo age in Europe. It is formed by two main structures: Quibas-Sima (divided into units QS-1 to QS-7) and Quibas-Cueva (QC-1– QC-6). In this work, we analyse the mineralogical composition of the sediments that form the stratigraphic units of Quibas-Sima using X-ray diffraction analysis, electrical conductivity, ion chromatography and optical emission spectrometry, to evaluate climatic trends in the sequence. Preliminary results indicate that there is an increase in the proportions of carbonates, gypsum and halite from QS-2 towards QS-4 and QS-5 (1.07–0.99 Ma), suggesting a progressive decrease in precipitation in south-eastern Iberian Peninsula a million years ago. Our data are consistent with the onset of a glacial phase, which is supported by the progressive disappearance of taxa related to forests and water bodies in Quibas-Sima, such as the flying squirrel Hylopetes sp. and the semiaquatic shrew Neomys sp., in favour of the appearance of taxa linked to open areas such as the Montpellier snake (Malpolon monspessulanus) and the snub-nosed viper (Vipera latastei). El yacimiento paleontológico de Quibas es un afloramiento kárstico con una edad comprendida entre 1,1 y 0,9 Ma (Pleistoceno Inferior tardío). Representa la única secuencia continua de vertebrados terrestres de edad pre-Jaramillo a Jaramillo de Europa. Está formado por dos estructuras principales: Quibas-Sima (dividida en las unidades QS-1 a QS-7) y Quibas-Cueva (QC-1 a QC-6). En este trabajo se estudia la composición mineralógica de los sedimentos que conforman las unidades estratigráficas de QuibasSima, a través e análisis de difracción de rayos X, conductividad eléctrica, cromatografía iónica y espectrometría de emisión óptica por plasma de argón, con el objetivo de evaluar tendencias paleoclimáticas en la secuencia. Los resultados preliminares indican que hay un aumento en las proporciones de carbonatos, yesos y halita desde QS-2 hacia QS-4 y QS-5 (1,07–0,99 Ma), lo que sugiere una progresiva disminución de las precipitaciones en el sureste peninsular hace un millón de años. Los datos son consistentes con el inicio de una fase glaciar, lo cual viene apoyado por la desaparición progresiva en Quibas-Sima de taxones afines a bosques y cursos de agua estables como la ardilla voladora Hylopetes sp. y el musgaño Neomys sp., en favor de la aparición de taxones ligados a espacios abiertos como la culebra bastarda (Malpolon monspessulanus) y la víbora hocicuda (Vipera latastei)

Transplantation of canine olfactory ensheathing cells producing chondroitinase ABC promotes chondroitin sulphate proteoglycan digestion and axonal sprouting following spinal cord injury

Olfactory ensheathing cell (OEC) transplantation is a promising strategy for treating spinal cord injury (SCI), as has been demonstrated in experimental SCI models and naturally occurring SCI in dogs. However, the presence of chondroitin sulphate proteoglycans within the extracellular matrix of the glial scar can inhibit efficient axonal repair and limit the therapeutic potential of OECs. Here we have used lentiviral vectors to genetically modify canine OECs to continuously deliver mammalian chondroitinase ABC at the lesion site in order to degrade the inhibitory chondroitin sulphate proteoglycans in a rodent model of spinal cord injury. We demonstrate that these chondroitinase producing canine OECs survived at 4 weeks following transplantation into the spinal cord lesion and effectively digested chondroitin sulphate proteoglycans at the site of injury. There was evidence of sprouting within the corticospinal tract rostral to the lesion and an increase in the number of corticospinal axons caudal to the lesion, suggestive of axonal regeneration. Our results indicate that delivery of the chondroitinase enzyme can be achieved with the genetically modified OECs to increase axon growth following SCI. The combination of these two promising approaches is a potential strategy for promoting neural regeneration following SCI in veterinary practice and human patients

Impact of phonon scattering mechanisms on the performance of silicene nanoribbon field-effect transistors

Rigorous efforts are invested globally in the semiconductor industry to leverage next-generation nanoelectronics beyond Moore's law. Among them, silicene is foreseen as a viable two-dimensional (2D) material for future transistor applications. In this study, we assessed the performance of field-effect transistors (FETs) based on silicene nanoribbons (SiNRs) in terms of width scaling, length scaling and non-ballistic phonon scattering effects. Simulation of the channel material and transistor is performed based on the nearest neighbour tight-binding model and the top-of-the-barrier nanotransistor model, respectively. The device performance is analysed by graphically extracting the on-to-off current ratio, subthreshold swing and drain-induced barrier lowering from the current–voltage characteristics. It is also revealed that the impact of phonon scattering effects becomes less significant as the channel lengths of the SiNR FETs become shorter than the mean free paths. Overall, it is shown that the width and length scaling are among the crucial factors in designing nanoribbon-based FETs owing to their unique properties

Reakcija β-amino-α,γ-dicianokrotononitrila s acetofenonom: sinteza derivata piridina, piridazina i tiofena s antimikrobnim djelovanjem

Condensation of β-amino-α,γ-dicyanocrotononitrile (1) with acetophenone gave the 2-amino-4-phenylpenta-1,3-diene-1,1,3-tricarbonitrile (2). The latter product was used in a series of heterocyclization reactions when react with different reagents like diazonium salts, hydrazines, hydroxylamine and elemental sulfur to give pyridazine, pyrazole, isoxazole and thiophene derivatives, respectively. On the other hand, it gave pyridine derivatives with aromatic aldehydes followed by reaction with cyanomethylene reagents. The MIC values for the newly synthesized product were measured against E. coli, B. cereus, B. subtilis and C. albicansKondenzacijom β-amino-α,γ-dicijanokrotononitrila 1 s acetofenonom dobiven je 2-amino-4-fenilpenta-1,3-dien-1,1,3-trikarbonitril (2) koji je upotrebljen u reakcijama heterociklizacije s različitim reagensima poput diazonijevih soli, hidrazina, hidroksilamina i elementarnog sumpora pri čemu su nastali derivati piridazina, pirazola, izoksazola, odnosno tiofena. Spoj 2 je u reakciji s aromatskim aldehidima te naknadno sa cijanometilenima dao derivate piridina. Određene su MIC vrijednosti za novosintetizirane spojeve protiv E. coli, B. cereus, B. subtilis i C. albicans